EP0662997B1 - Method for stabilising crude oils at the outlet of a well, and device therefor - Google Patents

Method for stabilising crude oils at the outlet of a well, and device therefor Download PDF

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Publication number
EP0662997B1
EP0662997B1 EP94923753A EP94923753A EP0662997B1 EP 0662997 B1 EP0662997 B1 EP 0662997B1 EP 94923753 A EP94923753 A EP 94923753A EP 94923753 A EP94923753 A EP 94923753A EP 0662997 B1 EP0662997 B1 EP 0662997B1
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EP
European Patent Office
Prior art keywords
crude oil
column
hydrocarbons
pipe
cut
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EP94923753A
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German (de)
French (fr)
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EP0662997A1 (en
Inventor
Jean-Paul Gourlia
Jacques Tournier Lasserve
Georges Bihn-Cirlot
Jean Vandermeersch
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Societe National Elf Aquitaine
Societe Nationale Elf Aquitaine Production SA
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Societe National Elf Aquitaine
Societe Nationale Elf Aquitaine Production SA
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    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G7/00—Distillation of hydrocarbon oils
    • C10G7/02—Stabilising gasoline by removing gases by fractioning
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
    • E21B43/34—Arrangements for separating materials produced by the well

Definitions

  • the present invention relates to a method of stabilization of crude oils at the well exit of extraction and the device for implementing the process.
  • the crude oil stabilization process is understood to mean the operation which consists in reducing the flow pressure of the crude oil leaving the well, generally between 10 and 100 bars at atmospheric pressure, while respecting a Reid vapor pressure of the around 0.69 bar at 38 ° C determined by API standard D323 while limiting losses to the atmosphere of light hydrocarbons, especially C 3 + hydrocarbons, that is to say made up of three to seven atoms of carbon commonly known as C 3 , C 4 , C 5 , C 6 and C 7 .
  • C 3 + hydrocarbons that is to say made up of three to seven atoms of carbon commonly known as C 3 , C 4 , C 5 , C 6 and C 7 .
  • This flash method does not allow the selective separation of C 3 hydrocarbons - from crude oil without degassing other products with higher added value.
  • the presence of C 3 - in stabilized crude oil makes it more sensitive to variations in temperature and pressure during subsequent operations, since these, C 3 - , can degas inadvertently.
  • the aim of the present invention is therefore to obtain a stabilized crude oil in which a maximum of C 4 + hydrocarbons will be recovered, that is to say the C 4 to C 7 hydrocarbons, generally not fully recovered. by techniques known to a person skilled in the art and adjusting the quantity of C 3 hydrocarbons in order to obtain the optimum Reid vapor pressure for its storage or subsequent transport.
  • the present invention therefore relates to a process for stabilizing crude oils at the outlet of the extraction well comprising a decompression step consisting of partially degassing and decanting part of the extracted reservoir water and a separation step consisting distilling said crude oil under pressure, said method being characterized in that during the decompression step, the vaporized C 4 to C 7 hydrocarbons are absorbed in an absorption liquid which is then mixed with said petroleum degassed and in that during the separation step, the said mixture is introduced into the middle part of a distillation column and distilled in at least two sections, including a gaseous section of C 1 to C 5 hydrocarbons recovered at the head of the column, and a cut of stabilized crude oil recovered below the point of injection of the native crude oil into the column.
  • Degassing, absorption, mixing operations and settling occur simultaneously in the same enclosure, or in separate enclosures, the liquid absorption being introduced against the flow of gas to trap hydrocarbons from C4 to C7 degassed during degassing by decompression of native crude oil.
  • the liquid absorption is a hydrocarbon from the group consisting of distilled cuts of stabilized crude oil and the stabilized crude oil itself and crude oil is decompressed for a decompression rate corresponding to ratio of the inlet pressure to the outlet pressure of the crude oil between 1 and 7.
  • distillation is done in a known conventional manner skilled in the art, that the column is lined with trays or includes fillings. So, we are going to create a reflux liquid at the top of the column and an upward flow of vapor, counter-current of liquid reflux, at the bottom of the column.
  • the part of the column located above the injection point of the native crude oil has the function of separating the hydrocarbons from C 1 to C 5 from the heavier hydrocarbons.
  • the part of the column located below this said injection point has the function of eliminating the C 1 , C 2 hydrocarbons and part of the C 3 from the crude oil, which allows the adjustment of the tension of stabilized crude oil vapor.
  • the native crude oil is distilled in two cuts, said cut gas at the top of the column and the crude oil cut stabilized at the bottom of the column, part of the cut stabilized crude oil being vaporized and then reinjected into bottom of column to create the rising steam flow.
  • the native crude oil entering the column is distilled in at least three cuts, a gaseous cut of C 1 to C 5 hydrocarbons drawn off at the head of the column, then a cut of stabilized crude oil drawn off in the middle part of the column and finally a heavy section of hydrocarbons, drawn off at the bottom of the column and consisting mainly of hydrocarbons having at least eight carbon atoms per molecule.
  • the gas cut is fractionated so as to be able to create a liquid reflux of C 4 and C 5 hydrocarbons containing a little C 3 hydrocarbons at the top of the column.
  • Part of the heavy cut of hydrocarbons is vaporized, then reinjected, i.e. recycled into the column to create the rising vapor flow necessary for the proper functioning of the distillation column.
  • the other part of this heavy cup, drawn at the bottom of column is advantageously recycled as a liquid absorption for the decompression stage, which avoids any consumption of additional product generating additional operating costs.
  • the minimum pressure inside the column distillation is chosen so as to avoid reaching a temperature below 0 ° C at the top of the column.
  • Pressure internal column will generally be between 4 bars and 15 bars.
  • Another object of the invention is the device implementing said method.
  • This device is characterized in that it includes a decompression unit partial native crude oil consisting of an enclosure closed with an inlet pipe at the top gas absorption liquid, and a distillation column including an oil charge line raw after decompression to be distilled, and at least two draw-off lines for gas cutting of hydrocarbons at the top of the column, and for cutting crude oil in below the crude oil injection point in the column.
  • the distillation column is connected at the head of the column, to at least one selective separation circuit by the draw-off line of the gas cut and by a line for injecting liquid hydrocarbons mainly of C 4 and C 5 , located below. the point of withdrawal of said gaseous cut in the column.
  • the selective separation circuit includes advantageously at least one selective separator of gaseous hydrocarbons chosen from the group of separators consisting of cryogenic groups, reactors adsorption / desorption, membrane separators selective, and at least one gas / liquid condenser.
  • the preferred selective separation circuit of the invention comprises at least one reactor adsorption / desorption filled with at least one adsorbent chosen from the group consisting of activated carbon, wool residues and molecular sieves.
  • the circuit comprises at least two activated carbon reactors operating alternately for the continuous implementation of the process adsorption / desorption of gases, as an adsorber reactor gas selection or as a desorber reactor.
  • a vapor stream is sent to the activated carbon, which requires an additional phase of drying thereof.
  • desorption times gas and activated carbon drying is at most equal to adsorption time of these, desorption operations and drying of the first reactor will happen easily while the gases are adsorbed on the activated carbon of the second reactor.
  • the partial decompression unit of native crude oil is constituted by an enclosure in the shape of an ovoid balloon comprising in its upper part an appendage comparable to a mini-distillation column of at least two theoretical plates, said enclosure comprising an inlet pipe for native crude oil, an outlet pipe for decanted water in its lower part, an outlet pipe for decompressed crude oil, added with absorption liquid loaded with C 4 to C 7 , a discharge pipe for light hydrocarbons, mainly C 1 and C 2 hydrocarbons, at the upper end of the appendix, and an inlet pipe for the absorption liquid.
  • the partial decompression unit for native crude oil can be replaced by a partial decompression circuit comprising a device characterized in that it comprises, upstream of the distillation column, a partial decompression circuit native crude oil constituted by a decompression chamber for native oil connected by a gas evacuation pipe to a separation-absorption column for degassed C 1 to C 7 hydrocarbons comprising a gas outlet pipe from C 1 to C 3 , an inlet pipe for the absorption liquid and an outlet pipe for the absorption liquid loaded with C 4 to C 7 hydrocarbons, and by a pipe for discharging the decompressed crude oil to a mixing / decantation enclosure comprising an inlet pipe for the absorption liquid loaded with C 4 to C 7 hydrocarbons, an outlet pipe for decanted water and an outlet pipe for the mixture angel crude oil-liquid to be distilled.
  • a partial decompression circuit native crude oil constituted by a decompression chamber for native oil connected by a gas evacuation pipe to a separation-absorption column for degassed C 1 to
  • the stabilized crude oil withdrawal line is located at the bottom of the column.
  • the distillation column is then connected at the bottom of the column, to a recycling circuit of a part of stabilized crude oil fitted with a reboiler through the crude oil withdrawal line stabilized and by a crude oil injection pipe vaporized, located above said draw-off line.
  • the distillation column comprises at least three draw-off lines, one for gas cutting in column head, one for stabilized crude oil in the middle part of the column, and finally one for the cut heavy with hydrocarbons at the bottom of the column.
  • the outlet pipe of said cut heavy is connected to the liquid inlet pipe absorption inside the decompression unit, to recycle the heavy cut of hydrocarbons as liquid absorption.
  • the distillation column is connected, at the head of column, to a selective section separation circuit gas by the withdrawal and injection lines previously described, and, at the bottom of the column, to a circuit recycle including a reboiler by the line of withdrawal of said heavy cut and by a pipe injection located above this draw point.
  • This recycles stabilized vaporized crude oil improves the economics of the stabilization process according to the invention.
  • This recycles has the effect of heating the charge of the mixture crude oil / adsorption liquid entering the column.
  • the invention in order to limit energy consumption for vaporizing the heavy cut in the reboiler of the recycling circuit, it is advantageous to replace the trays or the upholstery present in the middle part of the column, above the point of withdrawal of crude oil stabilized, by a device for exchanging material and heat which has the same separation function as trays or that the lining but which also allows reheat the charge in the column.
  • the device also comprises at least two exchangers, the first being placed on the pipe bringing the liquid absorption in the decompression chamber for the purpose of cool to the maximum and the second on the pipe of stabilized crude oil to bring this last at the required storage temperature.
  • the method according to the invention and its device will be easily transposable by a person skilled in the art to the treatment of condensate fields which are essentially gaseous deposits containing C 1 to C 4 hydrocarbons.
  • the aim is not to stabilize the fluids but to recover the liquid condensates of C 4 to C 8 hydrocarbons.
  • a hydrocarbon fraction distilling between 200 and 300 ° C., preferably gas oil will be introduced into the fluids to be distilled and recycled as adsorption liquid.
  • Figure 1 shows a first device of the invention.
  • Figure 2 shows a selective device separation circuit
  • Figure 3 shows a second device of the invention.
  • the device in FIG. 1 comprises a decompression unit 1 for the native crude oil arriving via line 3, and a distillation column 2 sized to have 10 to 30 theoretical plates, connected to unit 1 by line 7.
  • L unit 1 is a closed enclosure, constituted by a balloon surmounted by a mini-column 1b, dimensioned for at least two theoretical plates.
  • the water / crude oil / absorption liquid mixture may pass through an exchanger 27 making it possible to lower the temperature of the mixture before it enters the distillation column 2.
  • the cut of C 1 to C 5 hydrocarbons is evacuated via line 11 and then sent to a selective separation unit 13 which will make it possible to recover all of the condensed C 4 and C 5 hydrocarbons and a portion of C 3 hydrocarbons which will be directed to a buffer tank 16 via line 15, then reinjected at the top of the column via line 18 in order to create a liquid reflux therein.
  • a valve judiciously placed on the pipe 11 makes it possible to regulate the internal pressure of the distillation column 2.
  • the C 1 and C 2 hydrocarbons and the rest of the non-recovered C 3 hydrocarbons are discharged from the separation unit 13 via line 14 to be, for example, torched.
  • the stabilized crude oil is removed by the withdrawal line 9, then its temperature is lowered by passing it through the exchanger 10 to bring it back to an acceptable temperature for its storage.
  • a second withdrawal of the stabilized crude oil is done at the same level as the previous one, via line 24.
  • the oil passes through a reboiler 25 in which it partially vaporizes, before be reinjected into column 2 above its draw-off point via line 26.
  • the reinjection of partially vaporized crude oil makes it possible to obtain a better separation from light hydrocarbons in C 1 and C 2 likely to be there still trapped.
  • the heavy section of hydrocarbons is drawn off via line 12 and then directed towards reboiler 19 to be partially vaporized there.
  • the hydrocarbon vapors are reinjected into column 2 via line 20 while the thermally stable heavy cut is recovered by line 21 and recycled as absorption liquid in the mini-column 1b of enclosure 1 via exchanger 22, the pump 23 then the pipe 8.
  • This partial vaporization of said cut makes it possible to obtain a cut of stabilized crude oil, of perfectly controlled composition.
  • FIG. 2 we have a representation of a separation unit comprising three reactors 13a, 13b and 13c, filled with activated carbon, each of them corresponding to a different treatment step.
  • the reactor 13a corresponds to a phase of adsorption of the hydrocarbons from C 1 to C 5 withdrawn from the distillation column 1 via the line 11
  • the reactor 13b corresponds to a phase of vapor desorption of the hydrocarbons trapped on the coal active
  • the reactor 13c corresponds to a phase of drying the activated carbon with dry gaseous hydrocarbons, not previously trapped on the activated carbon, that is to say the C 1 and C 2 hydrocarbons.
  • line 30 brings steam generated for example by a boiler, onto the activated carbon of reactor 13b via line 30b, the valves of lines 30a and 30b for access to reactors 13a and 13b being closed.
  • the absorbed hydrocarbons are desorbed, preferably those in C 3 , then those in C 4 and finally those in C5 and are directed via line 15b in the duct 15. They pass through a condenser 34 and are then introduced in the settling tank 36 where the condensates are evacuated via line 35 to a water treatment unit.
  • the residual C 1 and C 2 hydrocarbons are sent via line 14 'to line 14 leading to the torch, and the liquid C 3 + hydrocarbons are returned via line 17 to the buffer tank 16.
  • the valves of lines 14b and 31b are closed.
  • the recycled dry gaseous hydrocarbons arriving in the reactor 13c via line 33c are evacuated via line 14c, the valves of lines 15c and 31c being closed. They are taken to line 14 to be burnt with a torch.
  • the device of FIG. 3 comprises a decompression circuit comprising a partial decompression chamber 31 connected on the one hand to the inlet pipe 3 of the native crude oil and on the other hand to a separation-absorption column 35 of the hydrocarbons of C 1 to C 7 degassed and to a mixing / decantation enclosure 38, said column 35 being itself connected to said enclosure 38, and a distillation column 2.
  • the native crude oil arriving via line 3 is expanded in the partial decompression enclosure 31.
  • the hydrocarbons from C 4 to C 7 are vaporized and entrained with the light hydrocarbons from C 1 to C 3 via the outlet pipe to the column separation-absorption 35 which passes through the exchanger 33a and the valve 33b.
  • the hydrocarbons from C 1 to C 3 are evacuated by the outlet pipe 36, the absorption liquid is introduced by the inlet pipe 48 and finally, the absorption liquid charged with the C 4 hydrocarbons to C 7 recovered is evacuated by the outlet pipe 37 connected to the inlet pipe to the mixing / decantation enclosure 38.
  • the partially decompressed crude oil in enclosure 31 is sent via line 32 to the mixing / decantation enclosure 38 where it is mixed with the absorption liquid loaded with C 4 to C 7 hydrocarbons then discharged via line 7.
  • Decanted native water is discharged through the pipe 34 of enclosure 31 and through line 39 of enclosure 38.
  • the water / oil mixture raw / absorption liquid passes through an exchanger 27 for lower the temperature of the mixture before entering the column 2.
  • the section of hydrocarbon from C 1 to C 5 is evacuated via line 11 and then sent to a selective separation unit 13 comprising a line 14 for evacuating hydrocarbons from C 1 to C 3 and a line 15 bringing back the condensed C 4 and C 5 hydrocarbons still charged with C 3 hydrocarbons towards a depropanizer 45.
  • the major part of the purified C 4 and C 5 hydrocarbons are reinjected at the top of the column via the lines 49 then 18.
  • the propeller operating as a column distilling includes a reboiling circuit (line 50, reboiler 50a) at the bottom of the propeller and a circuit recycle connected by lines 46 and 47a to the head of the depropanizer comprising an air cooler 46a.
  • Stabilized crude oil is recovered at the bottom of column 2 via line 28 connected on the one hand to a circuit reboiling via line 40, comprising a reboiler 40a.
  • Another part of the stabilized crude oil discharged from the enclosure 43 via the pipe 44 is recycled to the column 35 as absorption liquid. It can be partially loaded with C 2 to C 4 hydrocarbons coming from the depropanizer 45 via the pipe 47b.
  • the use of a depropanizer 45 is particularly advantageous because that only are back in the distillation column 2 the interesting hydrocarbons and that it also allows limit the size of the selective separation unit.
  • this depropanizer 45 provides good flexibility to produce either only crude oil or simultaneously liquefied gases and crude oil.
  • This example aims to compare performance of the method according to the invention with those of the technique previous implementation.
  • a system of at least three flash balloons is installed making it possible to decompress native crude oil, with departures of decompression vapors charged essentially gases such as nitrogen, carbon dioxide and C 1 and C 2 hydrocarbons for the first balloon, heavier hydrocarbons for the other balloons.
  • the native crude oil comes out with a pressure of 40 bars, at a temperature of around 48 ° C and a flow rate of around 350t / h (ton / hour).
  • the pressure is reduced to 27 bars, the vaporized gases are evacuated from the balloon, then led to the torch to be burned, while the decompressed crude oil is directed to a second decompression balloon.
  • the crude oil is decompressed from 27 to 6 bars; as before, the vaporized gases are sent to the torch and the decompressed crude oil is sent to a third and final balloon in which its pressure is reduced to 1.2 bar.
  • the native crude oil sent to enclosure 1 is decompressed from 40 to 27 bars, only the gaseous hydrocarbons of C 1 and C 2 are vaporized and discharged towards the torch to be burned there with a flow rate of 37 t / h.
  • the crude oil added with the absorption liquid loaded with C 3 , C 4 and C 5 hydrocarbons is discharged from the enclosure 1 at a flow rate of 382 t / h and a temperature of 48 ° C. It is cooled to 40 ° C in the exchanger 8, then is introduced into the distillation column.
  • the stabilized crude oil is collected at a temperature of 117 ° C, at atmospheric pressure and at a flow rate of 293 t / h through line 9 at the outlet of the column.
  • the Reid vapor pressure of the recycle in the middle of the column is of the order of 0.69 bar at 38 ° C and the pressure in the column is 8.5 bar.

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Abstract

PCT No. PCT/FR94/00950 Sec. 371 Date Jun. 26, 1995 Sec. 102(e) Date Jun. 26, 1995 PCT Filed Jul. 28, 1994 PCT Pub. No. WO95/04116 PCT Pub. Date Feb. 9, 1995A method and apparatus for stabilizing crude oil at the outlet of a well, including at least one separation step wherein the crude oil is pressure distilled in at least one distillation column into at least two cuts, i.e., a C1-5 hydrocarbon gas cut recovered at the top of the column and a stabilized crude oil cut recovered below the point where the original crude oil was injected into the column. The method advantageously includes at least one decompression step before the separation step.

Description

La présente invention concerne un procédé de stabilisation des pétroles bruts à la sortie du puits d'extraction et le dispositif de mise en oeuvre du procédé.The present invention relates to a method of stabilization of crude oils at the well exit of extraction and the device for implementing the process.

On entend par procédé de stabilisation des pétroles bruts l'opération qui consiste à ramener la pression en écoulement du pétrole brut en sortie de puits, comprise généralement entre 10 et 100 bars à la pression atmosphérique, en respectant une tension de vapeur Reid de l'ordre de 0,69 bar à 38°C déterminée par la norme API D323 tout en limitant les pertes à l'atmosphère en hydrocarbures légers notamment les hydrocarbures en C3 +, c'est-à-dire constitués de trois à sept atomes de carbone communément appelés C3, C4, C5, C6 et C7. Bien entendu par un tel procédé, on cherche à maximiser la production de pétrole brut en essayant de récupérer le maximum de C3 + mais en obtenant un pétrole brut stabilisé qui ne dégaze pas ou très faiblement.The crude oil stabilization process is understood to mean the operation which consists in reducing the flow pressure of the crude oil leaving the well, generally between 10 and 100 bars at atmospheric pressure, while respecting a Reid vapor pressure of the around 0.69 bar at 38 ° C determined by API standard D323 while limiting losses to the atmosphere of light hydrocarbons, especially C 3 + hydrocarbons, that is to say made up of three to seven atoms of carbon commonly known as C 3 , C 4 , C 5 , C 6 and C 7 . Of course, by such a process, it is sought to maximize the production of crude oil by trying to recover the maximum of C 3 + but by obtaining a stabilized crude oil which does not degas or very weakly.

Actuellement, pour stabiliser un pétrole brut sur un champ pétrolifère, on utilise un procédé mettant en oeuvre plusieurs flashs successifs. Il s'agit d'un procédé de décompression en plusieurs étapes permettant d'abaisser la pression du pétrole brut qui s'accompagne principalement d'un dégazage pas toujours contrôlable des hydrocarbures les plus légers en C3 -, c'est-à-dire des hydrocarbures constitués de moins de trois atomes de carbone soit C3, C2 et C1. Cependant, par flashs successifs, il est impossible de dégazer le pétrole brut en se limitant seulement aux hydrocarbures en C3 -, il y a fatalement des entraínements d'hydrocarbures en C3 + dans les gaz qui ne sont pas récupérés et des hydrocarbures en C3 - restent dilués dans le pétrole brut. Ce procédé par flashs ne permet pas de séparer sélectivement des hydrocarbures C3 - du pétrole brut sans dégazer d'autres produits à plus forte valeur ajoutée. La présence de C3 - dans le pétrole brut stabilisé le rend plus sensible aux variations de température et de pression lors des opérations ultérieures, puisque ceux-ci, les C3 -, peuvent se dégazer de façon intempestive.Currently, to stabilize crude oil on an oil field, a process using several successive flashes is used. It is a decompression process in several stages allowing to lower the pressure of crude oil which is mainly accompanied by a degassing not always controllable of the lightest hydrocarbons in C 3 - , that is to say say hydrocarbons made up of less than three carbon atoms, ie C 3 , C 2 and C 1 . However, by successive flashes, it is impossible to degas crude oil by being limited only to C 3 hydrocarbons - , there are inevitably entrainments of C 3 + hydrocarbons in the gases which are not recovered and hydrocarbons in C 3 - remain diluted in crude oil. This flash method does not allow the selective separation of C 3 hydrocarbons - from crude oil without degassing other products with higher added value. The presence of C 3 - in stabilized crude oil makes it more sensitive to variations in temperature and pressure during subsequent operations, since these, C 3 - , can degas inadvertently.

Ce problème du dégazage ultérieur du pétrole brut, notamment lors de son stockage ou de son transport, soit par bateau soit par pipe-line, peut être à l'origine de difficultés nombreuses et surtout d'accidents possibles.This problem of the subsequent degassing of crude oil, particularly during storage or transport, either by boat either by pipeline, may be the source of numerous difficulties and especially possible accidents.

Le but de la présente invention est donc d'obtenir un pétrole brut stabilisé dans lequel on va récupérer un maximum d'hydrocarbures en C4 +, c'est-à-dire les hydrocarbures de C4 à C7, généralement non totalement récupérés par les techniques connues de l'homme du métier et ajuster la quantité d'hydrocarbures en C3 en vue d'obtenir la tension de vapeur Reid optimale pour son stockage ou son transport ultérieur.The aim of the present invention is therefore to obtain a stabilized crude oil in which a maximum of C 4 + hydrocarbons will be recovered, that is to say the C 4 to C 7 hydrocarbons, generally not fully recovered. by techniques known to a person skilled in the art and adjusting the quantity of C 3 hydrocarbons in order to obtain the optimum Reid vapor pressure for its storage or subsequent transport.

La présente invention a donc pour objet un procédé de stabilisation des pétroles bruts à la sortie du puits d'extraction comprenant une étape de décompression consistant à le dégazer partiellement et à décanter une partie de l'eau de gisement extraite et une étape de séparation consistant à distiller sous pression ledit pétrole brut, le dit procédé étant caractérisé en ce qu'au cours de l'étape de décompression, les hydrocarbures de C4 à C7 vaporisés sont absorbés dans un liquide d'absorption qui est ensuite mélangé au dit pétrole dégazé et en ce que au cours de l'étape de séparation, le dit mélange est introduit dans la partie médiane d'une colonne à distiller et distillé en au moins deux coupes, dont une coupe gazeuse d'hydrocarbures de C1 à C5 récupérée en tête de colonne, et une coupe de pétrole brut stabilisé récupérée au-dessous du point d'injection du pétrole brut natif dans la colonne.The present invention therefore relates to a process for stabilizing crude oils at the outlet of the extraction well comprising a decompression step consisting of partially degassing and decanting part of the extracted reservoir water and a separation step consisting distilling said crude oil under pressure, said method being characterized in that during the decompression step, the vaporized C 4 to C 7 hydrocarbons are absorbed in an absorption liquid which is then mixed with said petroleum degassed and in that during the separation step, the said mixture is introduced into the middle part of a distillation column and distilled in at least two sections, including a gaseous section of C 1 to C 5 hydrocarbons recovered at the head of the column, and a cut of stabilized crude oil recovered below the point of injection of the native crude oil into the column.

Une telle configuration permet d'éviter tous problèmes liés à la forte décompression du pétrole brut natif sortant du puits s'il était directement introduit à l'intérieur de la colonne.Such a configuration makes it possible to avoid all problems related to the sharp decompression of crude oil native coming out of the well if it was directly introduced to inside the column.

Les opérations de dégazage, d'absorption, de mélange et de décantation se produisent simultanément dans une même enceinte, ou dans des enceintes séparées, le liquide d'absorption étant introduit à contre-courant du flux gazeux pour piéger les hydrocarbures de C4 à C7 dégazés lors du dégazage par décompression du pétrole brut natif.Degassing, absorption, mixing operations and settling occur simultaneously in the same enclosure, or in separate enclosures, the liquid absorption being introduced against the flow of gas to trap hydrocarbons from C4 to C7 degassed during degassing by decompression of native crude oil.

Dans cette étape de décompression, le liquide d'absorption est un hydrocarbure du groupe constitué par les coupes de distillation du pétrole brut stabilisé et le pétrole brut stabilisé lui-même et le pétrole brut est décompressé pour un taux de décompression correspondant au rapport de la pression d'entrée sur la pression de sortie du pétrole brut compris entre 1 et 7.In this decompression step, the liquid absorption is a hydrocarbon from the group consisting of distilled cuts of stabilized crude oil and the stabilized crude oil itself and crude oil is decompressed for a decompression rate corresponding to ratio of the inlet pressure to the outlet pressure of the crude oil between 1 and 7.

Dans la seconde étape du procédé de la présente invention, la distillation se fait de façon classique connue de l'homme du métier, que la colonne soit garnie de plateaux ou comprenne des garnissages. Ainsi, on va créer un reflux liquide en tête de colonne et un flux ascendant de vapeur, à contre-courant du reflux liquide, en fond de colonne.In the second step of the process of the present invention, distillation is done in a known conventional manner skilled in the art, that the column is lined with trays or includes fillings. So, we are going to create a reflux liquid at the top of the column and an upward flow of vapor, counter-current of liquid reflux, at the bottom of the column.

Ainsi, la partie de la colonne située au-dessus du point d'injection du pétrole brut natif a pour fonction de séparer les hydrocarbures de C1 à C5 des hydrocarbures plus lourds. La partie de la colonne située en-dessous de ce dit point d'injection a pour fonction d'éliminer les hydrocarbures en C1, C2 et une partie des C3 du pétrole brut, ce qui permet l'ajustement de la tension de vapeur du pétrole brut stabilisé.Thus, the part of the column located above the injection point of the native crude oil has the function of separating the hydrocarbons from C 1 to C 5 from the heavier hydrocarbons. The part of the column located below this said injection point has the function of eliminating the C 1 , C 2 hydrocarbons and part of the C 3 from the crude oil, which allows the adjustment of the tension of stabilized crude oil vapor.

Cependant, contrairement à la technique connue, au lieu de condenser la totalité de la coupe gazeuse avant de la réinjecter en tête de colonne pour créer le reflux, celle-ci va être séparée sélectivement en deux fractions, l'une constituée des hydrocarbures légers en C3 -, l'autre des hydrocarbures en C4, C5, et une partie des hydrocarbures en C3. Seule la fraction contenant les hydrocarbures en C4 et C5 est récupérée puis condensée et enfin réinjectée en tête de colonne. Cette séparation sélective en deux fractions d'hydrocarbures en C3 - et, en C4 et C5, est obtenue notamment par cryogénie, par adsorption/désorption, par séparation des gaz sur membrane et/ou par tout autre moyen permettant une séparation sélective de ces gaz. However, unlike the known technique, instead of condensing the entire gas fraction before reinjecting it at the top of the column to create reflux, it will be selectively separated into two fractions, one consisting of light hydrocarbons. C 3 - , the other of C 4 hydrocarbons, C 5 , and part of the C 3 hydrocarbons. Only the fraction containing the C 4 and C 5 hydrocarbons is recovered then condensed and finally reinjected at the top of the column. This selective separation into two C 3 - and C 4 and C 5 hydrocarbon fractions is obtained in particular by cryogenics, by adsorption / desorption, by gas separation on the membrane and / or by any other means allowing selective separation of these gases.

Dans un premier mode de réalisation du procédé, le pétrole brut natif est distillé en deux coupes, ladite coupe gazeuse en tête de colonne et la coupe de pétrole brut stabilisé en fond de colonne, une partie de la coupe de pétrole brut stabilisé étant vaporisée puis réinjectée en fond de colonne pour créer le flux de vapeur ascendant.In a first embodiment of the method, the native crude oil is distilled in two cuts, said cut gas at the top of the column and the crude oil cut stabilized at the bottom of the column, part of the cut stabilized crude oil being vaporized and then reinjected into bottom of column to create the rising steam flow.

Dans un second mode de réalisation du procédé, le pétrole brut natif entrant dans la colonne est distillé en au moins trois coupes, une coupe gazeuse d'hydrocarbures de C1 à C5 soutirée en tête de colonne, puis une coupe de pétrole brut stabilisé soutirée dans la partie médiane de la colonne et enfin une coupe lourde d'hydrocarbures, soutirée en fond de colonne et constituée majoritairement d'hydrocarbures ayant au moins huit atomes de carbone par molécule.In a second embodiment of the process, the native crude oil entering the column is distilled in at least three cuts, a gaseous cut of C 1 to C 5 hydrocarbons drawn off at the head of the column, then a cut of stabilized crude oil drawn off in the middle part of the column and finally a heavy section of hydrocarbons, drawn off at the bottom of the column and consisting mainly of hydrocarbons having at least eight carbon atoms per molecule.

Dans cette dernière coupe lourde, on peut tolérer la présence d'hydrocarbures plus légers en C6 et en C7.In this last heavy cut, we can tolerate the presence of lighter C 6 and C 7 hydrocarbons.

Dans ce mode préféré, la coupe gazeuse est fractionnée de façon à pouvoir créer en tête de colonne un reflux liquide d'hydrocarbures en C4 et en C5 contenant un peu d'hydrocarbures en C3.In this preferred embodiment, the gas cut is fractionated so as to be able to create a liquid reflux of C 4 and C 5 hydrocarbons containing a little C 3 hydrocarbons at the top of the column.

Une partie de la coupe lourde d'hydrocarbures est vaporisée, puis réinjectée, c'est-à-dire recyclée dans la colonne en vue de créer le flux de vapeur ascendant nécessaire au bon fonctionnement de la colonne à distiller. L'autre partie de cette coupe lourde, soutirée en fond de colonne, est, avantageusement recyclée comme liquide d'absorption pour l'étape de décompression, ce qui évite toute consommation de produit supplémentaire générateur de coûts opératoires supplémentaires.Part of the heavy cut of hydrocarbons is vaporized, then reinjected, i.e. recycled into the column to create the rising vapor flow necessary for the proper functioning of the distillation column. The other part of this heavy cup, drawn at the bottom of column is advantageously recycled as a liquid absorption for the decompression stage, which avoids any consumption of additional product generating additional operating costs.

Afin d'avoir un ajustement de la tension vapeur du pétrole brut stabilisé, on peut éventuellement vaporiser une partie du pétrole brut stabilisé qui sera réinjecté au-dessus du point de soutirage de ce dernier.In order to have an adjustment of the vapor pressure of the stabilized crude oil, you can optionally spray a part of the stabilized crude oil which will be reinjected above the latter's point of withdrawal.

Que l'étape de distillation soit précédée ou non d'une étape de décompression du pétrole brut natif, la pression minimale à l'intérieur de la colonne de distillation est choisie de façon à éviter d'atteindre une température inférieure à 0°C en tête de colonne. La pression interne de la colonne sera généralement comprise entre 4 bars et 15 bars.Whether the distillation step is preceded or not a step of decompression of native crude oil, the minimum pressure inside the column distillation is chosen so as to avoid reaching a temperature below 0 ° C at the top of the column. Pressure internal column will generally be between 4 bars and 15 bars.

Un autre objet de l'invention est le dispositif mettant en oeuvre ledit procédé. Ce dispositif est caractérisé en ce qu'il comporte une unité de décompression partielle du pétrole brut natif constituée d'une enceinte fermée comportant en tête une conduite d'arrivée d'un liquide d'absorption des gaz, et une colonne à distiller comprenant une conduite d'arrivée de la charge de pétrole brut après décompression à distiller, et au moins deux conduites de soutirage pour la coupe gazeuse d'hydrocarbures en tête de colonne, et pour la coupe de pétrole brut en dessous du point d'injection du pétrole brut dans la colonne.Another object of the invention is the device implementing said method. This device is characterized in that it includes a decompression unit partial native crude oil consisting of an enclosure closed with an inlet pipe at the top gas absorption liquid, and a distillation column including an oil charge line raw after decompression to be distilled, and at least two draw-off lines for gas cutting of hydrocarbons at the top of the column, and for cutting crude oil in below the crude oil injection point in the column.

La colonne de distillation est raccordée en tête de colonne, à au moins un circuit de séparation sélective par la conduite de soutirage de la coupe gazeuse et par une conduite d'injection des hydrocarbures liquides majoritairement en C4 et C5, située au-dessous du point de soutirage de ladite coupe gazeuse dans la colonne.The distillation column is connected at the head of the column, to at least one selective separation circuit by the draw-off line of the gas cut and by a line for injecting liquid hydrocarbons mainly of C 4 and C 5 , located below. the point of withdrawal of said gaseous cut in the column.

Le circuit de séparation sélective comprend avantageusement au moins un séparateur sélectif d'hydrocarbures gazeux choisi dans le groupe des séparateurs constitué par les groupes cryogéniques, les réacteurs d'adsorption/désorption, les séparateurs à membranes sélectives, et au moins un condenseur gaz/liquide. The selective separation circuit includes advantageously at least one selective separator of gaseous hydrocarbons chosen from the group of separators consisting of cryogenic groups, reactors adsorption / desorption, membrane separators selective, and at least one gas / liquid condenser.

Le circuit de séparation sélective préféré de l'invention comporte au moins un réacteur d'adsorption/désorption rempli d'au moins un adsorbant choisi dans le groupe constitué par les charbons actifs, les résidus lainiers et les tamis moléculaires.The preferred selective separation circuit of the invention comprises at least one reactor adsorption / desorption filled with at least one adsorbent chosen from the group consisting of activated carbon, wool residues and molecular sieves.

Dans un mode particulier de réalisation du dispositif de l'invention, le circuit comprend au moins deux réacteurs à charbon actif fonctionnant alternativement pour la mise en oeuvre en continu du procédé d'adsorption/désorption des gaz, comme réacteur adsorbeur sélectif des gaz ou comme réacteur désorbeur. Pour accélérer la désorption, un courant de vapeur est envoyé sur le charbon actif, ce qui nécessite une phase supplémentaire de séchage de celui-ci. Comme la somme des temps de désorption des gaz et de séchage du charbon actif est au plus égale au temps d'adsorption de ceux-ci, les opérations de désorption et de séchage du premier réacteur se produiront aisément pendant que les gaz s'adsorbent sur le charbon actif du deuxième réacteur.In a particular embodiment of the device of the invention, the circuit comprises at least two activated carbon reactors operating alternately for the continuous implementation of the process adsorption / desorption of gases, as an adsorber reactor gas selection or as a desorber reactor. To accelerate desorption, a vapor stream is sent to the activated carbon, which requires an additional phase of drying thereof. As the sum of the desorption times gas and activated carbon drying is at most equal to adsorption time of these, desorption operations and drying of the first reactor will happen easily while the gases are adsorbed on the activated carbon of the second reactor.

Dans le but d'éliminer toute trace d'hydrocarbures en C3 dans les hydrocarbures recyclés en tête de colonne, on disposera avantageusement en aval dudit séparateur sélectif sur le circuit ramenant des hydrocarbures en C4 et C5, une unité dite dépropaniseur pour ajuster la qualité du recycle aux besoins du procédé.In order to eliminate any trace of C 3 hydrocarbons in the hydrocarbons recycled at the head of the column, there will advantageously be available downstream of said selective separator on the circuit bringing back C 4 and C 5 hydrocarbons, a so-called depropanizer unit for adjusting the quality of the recycling to the needs of the process.

Selon l'invention, l'unité de décompression partielle du pétrole brut natif, est constituée par une enceinte en forme de ballon ovoïde comprenant dans sa partie supérieure un appendice comparable à une mini-colonne de distillation d'au moins deux plateaux théoriques, ladite enceinte comportant une conduite d'entrée du pétrole brut natif, une conduite d'évacuation de l'eau décantée dans sa partie inférieure, une conduite de sortie du pétrole brut décompressé, additionné du liquide d'absorption chargé d'hydrocarbures de C4 à C7, une conduite d'évacuation des hydrocarbures légers, majoritairement des hydrocarbures en C1 et C2, à l'extrémité supérieure de l'appendice, et une conduite d'entrée du liquide d'absorption.According to the invention, the partial decompression unit of native crude oil, is constituted by an enclosure in the shape of an ovoid balloon comprising in its upper part an appendage comparable to a mini-distillation column of at least two theoretical plates, said enclosure comprising an inlet pipe for native crude oil, an outlet pipe for decanted water in its lower part, an outlet pipe for decompressed crude oil, added with absorption liquid loaded with C 4 to C 7 , a discharge pipe for light hydrocarbons, mainly C 1 and C 2 hydrocarbons, at the upper end of the appendix, and an inlet pipe for the absorption liquid.

Dans un autre mode de réalisation du dispositif, on peut remplacer l'unité de décompression partielle du pétrole brut natif par un circuit de décompression partielle comprenant un dispositif caractérisé en ce qu'il comprend en amont de la colonne de distillation un circuit de décompression partielle du pétrole brut natif constitué par une enceinte de décompression du pétrole natif reliée par une conduite d'évacuation des gaz à une colonne de séparation-absorption des hydrocarbures de C1 à C7 dégazés comprenant une conduite de sortie des gaz de C1 à C3, une conduite d'entrée du liquide d'absorption et une conduite de sortie du liquide d'absorption chargé en hydrocarbures de C4 à C7, et par une conduite d'évacuation du pétrole brut décompressé à une enceinte mélange/décantation comprenant une conduite d'entrée du liquide d'absorption chargé en hydrocarbures de C4 à C7, une conduite de sortie de l'eau décantée et une conduite de sortie du mélange pétrole brut-liquide d'absorption à distiller.In another embodiment of the device, the partial decompression unit for native crude oil can be replaced by a partial decompression circuit comprising a device characterized in that it comprises, upstream of the distillation column, a partial decompression circuit native crude oil constituted by a decompression chamber for native oil connected by a gas evacuation pipe to a separation-absorption column for degassed C 1 to C 7 hydrocarbons comprising a gas outlet pipe from C 1 to C 3 , an inlet pipe for the absorption liquid and an outlet pipe for the absorption liquid loaded with C 4 to C 7 hydrocarbons, and by a pipe for discharging the decompressed crude oil to a mixing / decantation enclosure comprising an inlet pipe for the absorption liquid loaded with C 4 to C 7 hydrocarbons, an outlet pipe for decanted water and an outlet pipe for the mixture angel crude oil-liquid to be distilled.

Dans un premier mode de réalisation du dispositif, la conduite de soutirage du pétrole brut stabilisé est située en fond de colonne. La colonne de distillation est alors raccordée en fond de colonne, à un circuit de recycle d'une partie du pétrole brut stabilisé équipé d'un rebouilleur par la conduite de soutirage du pétrole brut stabilisé et par une conduite d'injection du pétrole brut vaporisé, située au-dessus de ladite conduite de soutirage.In a first embodiment of the device, the stabilized crude oil withdrawal line is located at the bottom of the column. The distillation column is then connected at the bottom of the column, to a recycling circuit of a part of stabilized crude oil fitted with a reboiler through the crude oil withdrawal line stabilized and by a crude oil injection pipe vaporized, located above said draw-off line.

Dans un second mode de réalisation du dispositif selon l'invention, la colonne à distiller comprend au moins trois conduites de soutirage, une pour la coupe gazeuse en tête de colonne, une pour le pétrole brut stabilisé dans la partie médiane de la colonne, et enfin une pour la coupe lourde d'hydrocarbures en fond de colonne. Dans ce dispositif préféré, la conduite de sortie de ladite coupe lourde est reliée à la conduite d'entrée du liquide d'absorption dans l'enceinte de l'unité de décompression, pour recycler la coupe lourde d'hydrocarbures comme liquide d'absorption.In a second embodiment of the device according to the invention, the distillation column comprises at least three draw-off lines, one for gas cutting in column head, one for stabilized crude oil in the middle part of the column, and finally one for the cut heavy with hydrocarbons at the bottom of the column. In this preferred device, the outlet pipe of said cut heavy is connected to the liquid inlet pipe absorption inside the decompression unit, to recycle the heavy cut of hydrocarbons as liquid absorption.

Dans ce mode particulier du dispositif de l'invention, la colonne à distiller est reliée, en tête de colonne, à un circuit de séparation sélective de la coupe gazeuse par les conduites de soutirage et d'injection précédemment décrites, et, en fond de colonne, à un circuit de recycle comprenant un rebouilleur par la conduite de soutirage de ladite coupe lourde et par une conduite d'injection située au-dessus de ce point de soutirage.In this particular mode of the the invention, the distillation column is connected, at the head of column, to a selective section separation circuit gas by the withdrawal and injection lines previously described, and, at the bottom of the column, to a circuit recycle including a reboiler by the line of withdrawal of said heavy cut and by a pipe injection located above this draw point.

Eventuellement, on peut relier la colonne dans sa partie médiane à un circuit de recycle de pétrole brut stabilisé équipé d'un rebouilleur par une deuxième conduite de soutirage située au même niveau que la conduite de soutirage du pétrole brut stabilisé, et par une conduite d'injection du pétrole brut vaporisé située au-dessus de cette dite deuxième conduite de soutirage. Ce recycle de pétrole brut stabilisé vaporisé permet d'améliorer l'économie du procédé de stabilisation selon l'invention. Ce recycle a pour effet de chauffer la charge du mélange pétrole brut/liquide d'adsorption entrant dans la colonne. Dans un mode particulier de réalisation du dispositif de l'invention, en vue de limiter la consommation d'énergie pour la vaporisation de la coupe lourde dans le rebouilleur du circuit de recycle, on peut avantageusement remplacer les plateaux ou le garnissage présents dans la partie médiane de la colonne, au-dessus du point de soutirage du pétrole brut stabilisé, par un dispositif d'échanges de matière et de chaleur qui a la même fonction de séparation que les plateaux ou que le garnissage mais qui permet en outre de réchauffer la charge dans la colonne.Optionally, you can connect the column in its middle part to a crude oil recycling circuit stabilized equipped with a reboiler by a second pipe withdrawal located at the same level as the withdrawal of stabilized crude oil, and through a pipeline injection of vaporized crude oil located above this so-called second withdrawal line. This recycles stabilized vaporized crude oil improves the economics of the stabilization process according to the invention. This recycles has the effect of heating the charge of the mixture crude oil / adsorption liquid entering the column. In a particular embodiment of the device the invention, in order to limit energy consumption for vaporizing the heavy cut in the reboiler of the recycling circuit, it is advantageous to replace the trays or the upholstery present in the middle part of the column, above the point of withdrawal of crude oil stabilized, by a device for exchanging material and heat which has the same separation function as trays or that the lining but which also allows reheat the charge in the column.

Dans ce mode de réalisation de l'invention, le dispositif comprend en outre au moins deux échangeurs, le premier étant placé sur la conduite amenant le liquide d'absorption dans l'enceinte de décompression aux fins de le refroidir au maximum et le second sur la conduite d'évacuation du pétrole brut stabilisé pour ramener ce dernier à la température requise de stockage. In this embodiment of the invention, the device also comprises at least two exchangers, the first being placed on the pipe bringing the liquid absorption in the decompression chamber for the purpose of cool to the maximum and the second on the pipe of stabilized crude oil to bring this last at the required storage temperature.

Le procédé selon l'invention ainsi que son dispositif seront facilement transposables par l'homme du métier au traitement des champs de condensat qui sont pour l'essentiel des gisements gazeux contenant des hydrocarbures de C1 à C4. Dans ces champs, on ne cherche pas la stabilisation des fluides mais une récupération des condensats liquides d'hydrocarbures de C4 à C8. Bien entendu, dans le procédé combinant une étape de décompression à l'étape de distillation une coupe hydrocarbonée distillant entre 200 et 300°C, de préférence du gasoil, sera introduite dans les fluides à distiller et recyclée comme liquide d'adsorptionThe method according to the invention and its device will be easily transposable by a person skilled in the art to the treatment of condensate fields which are essentially gaseous deposits containing C 1 to C 4 hydrocarbons. In these fields, the aim is not to stabilize the fluids but to recover the liquid condensates of C 4 to C 8 hydrocarbons. Of course, in the process combining a decompression step with the distillation step, a hydrocarbon fraction distilling between 200 and 300 ° C., preferably gas oil, will be introduced into the fluids to be distilled and recycled as adsorption liquid.

Pour éclairer le procédé de l'invention et le dispositif de mise en oeuvre y afférent, nous nous proposons de décrire les figures 1, 2 et 3 ci-après.To clarify the process of the invention and the related implementation device, we offer describe Figures 1, 2 and 3 below.

La figure 1 présente un premier dispositif de l'invention. Figure 1 shows a first device of the invention.

La figure 2 présente un circuit de séparation sélective du dispositif. Figure 2 shows a selective device separation circuit.

La figure 3 présente un second dispositif de l'invention. Figure 3 shows a second device of the invention.

Le dispositif de la figure 1 comprend une unité de décompression 1 du pétrole brut natif arrivant par la conduite 3, et une colonne à distiller 2 dimensionnée pour avoir de 10 à 30 plateaux théoriques, raccordée à l'unité 1 par la conduite 7. L'unité 1 est une enceinte fermée, constituée par un ballon la surmonté d'une mini-colonne 1b, dimensionnée pour au moins deux plateaux théoriques.The device in FIG. 1 comprises a decompression unit 1 for the native crude oil arriving via line 3, and a distillation column 2 sized to have 10 to 30 theoretical plates, connected to unit 1 by line 7. L unit 1 is a closed enclosure, constituted by a balloon surmounted by a mini-column 1b, dimensioned for at least two theoretical plates.

Le pétrole brut natif détendu par l'intermédiaire de la vanne 4 et pénétrant dans le ballon la par la conduite 3, est décomprimé. Sous l'effet de la décompression, une partie des hydrocarbures de C4 à C7 est vaporisée et entraínée dans la mini-colonne 1b où ces hydrocarbures sont séparés. Une partie des hydrocarbures de C4 à C7 retombent ainsi dans le ballon la. Pour récupérer la totalité de ces hydrocarbures de C4 à C7, un liquide hydrocarboné, appelé liquide d'absorption, stable à la température et à la pression de l'enceinte 1, est injecté à contre-courant du flux gazeux, près du point d'évacuation des hydrocarbures en C1 et C2 non condensables, via la conduite 6, à la tête de la mini-colonne par la conduite 8. En retombant dans le ballon la, le liquide d'absorption se mélange au pétrole brut et à l'eau de gisement non décantée, l'ensemble étant évacué de l'enceinte 1 par la conduite 7. L'eau décantée dans le ballon la est évacuée par la conduite 5.The native crude oil expanded through the valve 4 and entering the balloon la through line 3, is decompressed. Under the effect of decompression, part of the C 4 to C 7 hydrocarbons is vaporized and entrained in the mini-column 1b where these hydrocarbons are separated. Part of the hydrocarbons from C 4 to C 7 thus fall back into the balloon la. To recover all of these C 4 to C 7 hydrocarbons, a hydrocarbon liquid, called absorption liquid, stable at the temperature and pressure of enclosure 1, is injected against the flow of gas, near the discharge point for non-condensable C 1 and C 2 hydrocarbons, via line 6, at the head of the mini-column via line 8. By falling back into the flask la, the absorption liquid mixes with the crude oil and with non-decanted reservoir water, the assembly being evacuated from enclosure 1 by line 7. The water decanted in the flask 1a is evacuated by line 5.

A la sortie de l'enceinte 1, le mélange eau/pétrole brut/liquide d'absorption pourra traverser un échangeur 27 permettant d'abaisser la température du mélange avant son entrée dans la colonne de distillation 2. En tête de colonne, la coupe d'hydrocarbures de C1 à C5 est évacuée par la conduite 11 puis envoyée dans une unité de séparation sélective 13 qui va permettre de récupérer tous les hydrocarbures condensés en C4 et C5 et une partie d'hydrocarbures en C3 qui vont être dirigés vers un ballon tampon 16 via la conduite 15, puis réinjectés en tête de colonne via la conduite 18 afin de créer un reflux liquide dans cette dernière. Une vanne judicieusement placée sur la conduite 11 permet de réguler la pression interne de la colonne à distiller 2. Parallèlement, les hydrocarbures en C1 et C2 et le reste des hydrocarbures en C3 non récupérés sont évacués de l'unité de séparation 13 via la conduite 14 pour être par exemple brûlés à la torche.At the outlet of enclosure 1, the water / crude oil / absorption liquid mixture may pass through an exchanger 27 making it possible to lower the temperature of the mixture before it enters the distillation column 2. At the head of the column, the cut of C 1 to C 5 hydrocarbons is evacuated via line 11 and then sent to a selective separation unit 13 which will make it possible to recover all of the condensed C 4 and C 5 hydrocarbons and a portion of C 3 hydrocarbons which will be directed to a buffer tank 16 via line 15, then reinjected at the top of the column via line 18 in order to create a liquid reflux therein. A valve judiciously placed on the pipe 11 makes it possible to regulate the internal pressure of the distillation column 2. At the same time, the C 1 and C 2 hydrocarbons and the rest of the non-recovered C 3 hydrocarbons are discharged from the separation unit 13 via line 14 to be, for example, torched.

Dans la partie médiane de la colonne 2, on évacue le pétrole brut stabilisé par la conduite de soutirage 9, puis on abaisse sa température en le faisant traverser l'échangeur 10 pour le ramener à une température admissible pour son stockage. Cependant, pour ajuster la tension de vapeur du pétrole brut stabilisé, un deuxième soutirage du pétrole brut stabilisé est fait au même niveau que le précédent, via la conduite 24. Le pétrole traverse un rebouilleur 25 dans lequel il se vaporise partiellement, avant d'être réinjecté dans la colonne 2 au-dessus de son point de soutirage via la conduite 26. La réinjection du pétrole brut partiellement vaporisé permet d'obtenir une meilleure séparation d'avec les hydrocarbures légers en C1 et C2 susceptibles d'y être encore piégés. En fond de colonne, la coupe lourde d'hydrocarbures est soutirée via la conduite 12 puis dirigée vers le rebouilleur 19 pour y être partiellement vaporisée. Les vapeurs hydrocarbonées sont réinjectées dans la colonne 2 via la conduite 20 tandis que la coupe lourde stable thermiquement est récupérée par la ligne 21 et recyclée comme liquide d'absorption dans la mini-colonne 1b de l'enceinte 1 via l'échangeur 22, la pompe 23 puis la conduite 8. Cette vaporisation partielle de ladite coupe permet d'obtenir une coupe de pétrole brut stabilisé, de composition parfaitement maítrisée.In the middle part of column 2, the stabilized crude oil is removed by the withdrawal line 9, then its temperature is lowered by passing it through the exchanger 10 to bring it back to an acceptable temperature for its storage. However, to adjust the vapor pressure of the stabilized crude oil, a second withdrawal of the stabilized crude oil is done at the same level as the previous one, via line 24. The oil passes through a reboiler 25 in which it partially vaporizes, before be reinjected into column 2 above its draw-off point via line 26. The reinjection of partially vaporized crude oil makes it possible to obtain a better separation from light hydrocarbons in C 1 and C 2 likely to be there still trapped. At the bottom of the column, the heavy section of hydrocarbons is drawn off via line 12 and then directed towards reboiler 19 to be partially vaporized there. The hydrocarbon vapors are reinjected into column 2 via line 20 while the thermally stable heavy cut is recovered by line 21 and recycled as absorption liquid in the mini-column 1b of enclosure 1 via exchanger 22, the pump 23 then the pipe 8. This partial vaporization of said cut makes it possible to obtain a cut of stabilized crude oil, of perfectly controlled composition.

Dans la figure 2, nous avons une représentation d'une unité de séparation comprenant trois réacteurs 13a, 13b et 13c, remplis de charbon actif, chacun d'entre eux correspondant à une étape de traitement différente. Ainsi, le réacteur 13a correspond à une phase d'adsorption des hydrocarbures de C1 à C5 soutirés de la colonne de distillation 1 via la conduite 11, le réacteur 13b correspond à une phase de désorption à la vapeur des hydrocarbures piégés sur le charbon actif et le réacteur 13c correspond à une phase de séchage du charbon actif par les hydrocarbures gazeux secs, non piégés précédemment sur le charbon actif, c'est-à-dire les hydrocarbures en C1 et C2.In Figure 2 , we have a representation of a separation unit comprising three reactors 13a, 13b and 13c, filled with activated carbon, each of them corresponding to a different treatment step. Thus, the reactor 13a corresponds to a phase of adsorption of the hydrocarbons from C 1 to C 5 withdrawn from the distillation column 1 via the line 11, the reactor 13b corresponds to a phase of vapor desorption of the hydrocarbons trapped on the coal active and the reactor 13c corresponds to a phase of drying the activated carbon with dry gaseous hydrocarbons, not previously trapped on the activated carbon, that is to say the C 1 and C 2 hydrocarbons.

Lors de l'adsorption des hydrocarbures, ceux-ci arrivent sur le réacteur 13a via la conduite 11 : les vannes placées sur les autres lignes d'accès à celui-ci, 11b et 11c, sont fermées. Seuls, les hydrocarbures en C3 +, préférentiellement ceux en C5, puis ceux en C4, et enfin partiellement ceux en C3 seront piégés sur le charbon actif, tandis que les hydrocarbures gazeux en C1 et C2 non piégés par le charbon actif seront évacués via la ligne 31a pour rejoindre la ligne 31 et être recyclés, après réchauffage dans l'échangeur 32, pour le séchage du charbon actif du réacteur 13c via la ligne 33c, les vannes des lignes 33a et 33b d'accès aux réacteurs 13a et 13b étant fermées.During the adsorption of the hydrocarbons, these arrive on the reactor 13a via the pipe 11: the valves placed on the other access lines to the latter, 11b and 11c, are closed. Only the C 3 + hydrocarbons, preferably those of C 5 , then those of C 4 , and finally partially those of C 3 will be trapped on the activated carbon, while the gaseous hydrocarbons of C 1 and C 2 not trapped by the activated carbon will be evacuated via line 31a to join line 31 and be recycled, after reheating in the exchanger 32, for drying the activated carbon from reactor 13c via line 33c, the valves of lines 33a and 33b for access to reactors 13a and 13b being closed.

Au cours de la désorption, la ligne 30 amène de la vapeur générée par exemple par une chaudière, sur le charbon actif du réacteur 13b via la ligne 30b, les vannes des lignes 30a et 30b d'accès aux réacteurs 13a et 13b étant fermées. Sous l'action de la vapeur, les hydrocarbures absorbés se désorbent, préférentiellement ceux en C3, puis ceux en C4 et enfin ceux en C5 et se dirigent via la ligne 15b dans le conduit 15. Ils traversent un condenseur 34 puis sont introduits dans le ballon de décantation 36 où les condensats sont évacués via la ligne 35 vers une unité de traitement des eaux. Les hydrocarbures en C1 et C2 résiduels sont envoyés via la ligne 14' à la ligne 14 conduisant à la torche, et les hydrocarbures en C3 + liquides sont renvoyés via la conduite 17 vers le ballon tampon 16. Les vannes des lignes 14b et 31b sont fermées.During desorption, line 30 brings steam generated for example by a boiler, onto the activated carbon of reactor 13b via line 30b, the valves of lines 30a and 30b for access to reactors 13a and 13b being closed. Under the action of steam, the absorbed hydrocarbons are desorbed, preferably those in C 3 , then those in C 4 and finally those in C5 and are directed via line 15b in the duct 15. They pass through a condenser 34 and are then introduced in the settling tank 36 where the condensates are evacuated via line 35 to a water treatment unit. The residual C 1 and C 2 hydrocarbons are sent via line 14 'to line 14 leading to the torch, and the liquid C 3 + hydrocarbons are returned via line 17 to the buffer tank 16. The valves of lines 14b and 31b are closed.

Pour sécher le charbon actif du réacteur 13c, les hydrocarbures gazeux secs recyclés arrivant dans le réacteur 13c via la ligne 33c sont évacués via la ligne 14c, les vannes des lignes 15c et 31c étant fermées. Ils sont conduits vers la ligne 14 pour être brûlés à la torche.To dry the activated carbon in reactor 13c, the recycled dry gaseous hydrocarbons arriving in the reactor 13c via line 33c are evacuated via line 14c, the valves of lines 15c and 31c being closed. They are taken to line 14 to be burnt with a torch.

Lorsque la phase d'adsorption dans le réacteur 13a est terminée, celle-ci étant généralement la plus longue, on commence la phase de désorption des hydrocarbures. Au même moment commence dans le réacteur 13b, le séchage du charbon actif et dans le réacteur 13c, l'adsorption des hydrocarbures gazeux provenant de la colonne à distiller 2. Pour ce procédé d'adsorption/désorption, il suffit de permuter les phases dans les réacteurs pour comprendre comment le procédé fonctionne en continu.When the adsorption phase in reactor 13a is finished, this being generally the longest, we begins the hydrocarbon desorption phase. The same moment begins in reactor 13b, drying coal active and in reactor 13c, the adsorption of gaseous hydrocarbons from the distillation column 2. For this adsorption / desorption process, just swap phases in reactors to understand how the process works continuously.

Le dispositif de la figure 3 comprend un circuit de décompression comprenant une enceinte de décompression partielle 31 reliée d'une part à la conduite d'arrivée 3 du pétrole brut natif et d'autre part à une colonne de séparation-absorption 35 des hydrocarbures de C1 à C7 dégazés et à une enceinte de mélange / décantation 38, ladite colonne 35 étant elle-même raccordée à ladite enceinte 38, et une colonne à distiller 2.The device of FIG. 3 comprises a decompression circuit comprising a partial decompression chamber 31 connected on the one hand to the inlet pipe 3 of the native crude oil and on the other hand to a separation-absorption column 35 of the hydrocarbons of C 1 to C 7 degassed and to a mixing / decantation enclosure 38, said column 35 being itself connected to said enclosure 38, and a distillation column 2.

Le pétrole brut natif arrivant par la conduite 3 est détendu dans l'enceinte de décompression partielle 31. Les hydrocarbures de C4 à C7 sont vaporisés et entraínés avec les hydrocarbures légers de C1 à C3 via la conduite de sortie vers la colonne de séparation-absorption 35 qui traverse l'échangeur 33a et la vanne 33b. Dans ladite colonne 35, les hydrocarbures de C1 à C3 sont évacués par la conduite de sortie 36, le liquide d'absorption est introduit par la conduite d'entrée 48 et enfin, le liquide d'absorption chargé des hydrocarbures de C4 à C7 récupérés est évacué par la conduite de sortie 37 reliée à la conduite d'entrée à l'enceinte de mélange / décantation 38.The native crude oil arriving via line 3 is expanded in the partial decompression enclosure 31. The hydrocarbons from C 4 to C 7 are vaporized and entrained with the light hydrocarbons from C 1 to C 3 via the outlet pipe to the column separation-absorption 35 which passes through the exchanger 33a and the valve 33b. In said column 35, the hydrocarbons from C 1 to C 3 are evacuated by the outlet pipe 36, the absorption liquid is introduced by the inlet pipe 48 and finally, the absorption liquid charged with the C 4 hydrocarbons to C 7 recovered is evacuated by the outlet pipe 37 connected to the inlet pipe to the mixing / decantation enclosure 38.

Le pétrole brut partiellement décompressé dans l'enceinte 31 est envoyé via la conduite 32 dans l'enceinte de mélange / décantation 38 où il est mélangé au liquide d'absorption chargé en hydrocarbures de C4 à C7 puis évacué via la conduite 7.The partially decompressed crude oil in enclosure 31 is sent via line 32 to the mixing / decantation enclosure 38 where it is mixed with the absorption liquid loaded with C 4 to C 7 hydrocarbons then discharged via line 7.

De l'eau native décantée est évacuée par la conduite 34 de l'enceinte 31 et par la conduite 39 de l'enceinte 38.Decanted native water is discharged through the pipe 34 of enclosure 31 and through line 39 of enclosure 38.

A la sortie de l'enceinte 38, le mélange eau/pétrole brut/liquide d'absorption traverse un échangeur 27 pour abaisser la température du mélange avant son entrée dans la colonne 2.At the exit of enclosure 38, the water / oil mixture raw / absorption liquid passes through an exchanger 27 for lower the temperature of the mixture before entering the column 2.

En tête de colonne 2, la coupe d'hydrocarbure de C1 à C5 est évacuée par la conduite 11 puis envoyée dans une unité de séparation sélective 13 comprenant une conduite 14 d'évacuation des hydrocarbures de C1 à C3 et une conduite 15 ramenant les hydrocarbures condensés en C4 et C5 chargés encore d'hydrocarbures en C3 vers un dépropaniseur 45. La majeure partie des hydrocarbures en C4 et C5 purifiés sont réinjectés en tête de colonne via les conduites 49 puis 18.At the top of column 2, the section of hydrocarbon from C 1 to C 5 is evacuated via line 11 and then sent to a selective separation unit 13 comprising a line 14 for evacuating hydrocarbons from C 1 to C 3 and a line 15 bringing back the condensed C 4 and C 5 hydrocarbons still charged with C 3 hydrocarbons towards a depropanizer 45. The major part of the purified C 4 and C 5 hydrocarbons are reinjected at the top of the column via the lines 49 then 18.

Le dépropaniseur fonctionnant comme une colonne à distiller comprend un circuit de rebouillage (conduite 50, rebouilleur 50a) en fond de dépropaniseur et un circuit de recycle raccordé par les conduites 46 et 47a à la tête du dépropaniseur comprenant un aéroréfrigérant 46a.The propeller operating as a column distilling includes a reboiling circuit (line 50, reboiler 50a) at the bottom of the propeller and a circuit recycle connected by lines 46 and 47a to the head of the depropanizer comprising an air cooler 46a.

Le pétrole brut stabilisé est récupéré en fond de colonne 2 via la conduite 28 reliée d'une part à un circuit de rebouillage via la conduite 40, comprenant un rebouilleur 40a.Stabilized crude oil is recovered at the bottom of column 2 via line 28 connected on the one hand to a circuit reboiling via line 40, comprising a reboiler 40a.

Une partie de ce pétrole brut stabilisé de la conduite 28 est détendue au moyen de la vanne 42 provoquant la vaporisation partielle des hydrocarbures de C3 à C8, puis elle est envoyée dans l'enceinte 43 où les phases vapeurs et liquides sont séparées. La phase vapeur, retournée via la conduite 41b rejoint le pétrole brut stabilisé directement récupéré en fond de colonne 2 via les conduites 28 puis 41a, pour être évacué par la conduite 41.Part of this stabilized crude oil from line 28 is expanded by means of the valve 42 causing partial vaporization of the hydrocarbons from C 3 to C 8 , then it is sent to the enclosure 43 where the vapor and liquid phases are separated. The vapor phase, returned via line 41b joins the stabilized crude oil directly recovered at the bottom of column 2 via lines 28 then 41a, to be evacuated via line 41.

Une autre partie du pétrole brut stabilisé évacué de l'enceinte 43 via la conduite 44 est recyclée dans la colonne 35 comme liquide d'absorption. Elle peut être partiellement chargée en hydrocarbures de C2 à C4 venant du dépropaniseur 45 via la conduite 47b.Another part of the stabilized crude oil discharged from the enclosure 43 via the pipe 44 is recycled to the column 35 as absorption liquid. It can be partially loaded with C 2 to C 4 hydrocarbons coming from the depropanizer 45 via the pipe 47b.

Dans ce dispositif selon la figure 3, l'utilisation d'un dépropaniseur 45 est particulièrement avantageuse parce que seuls sont de retour dans la colonne à distiller 2 les hydrocarbures intéressants et qu'il permet en outre de limiter la taille de l'unité de séparation sélective. Par ailleurs, ce dépropaniseur 45 apporte une bonne flexibilité permettant de produire soit uniquement du pétrole brut, soit simultanément des gaz liquéfiés et du pétrole brut.In this device according to FIG. 3, the use of a depropanizer 45 is particularly advantageous because that only are back in the distillation column 2 the interesting hydrocarbons and that it also allows limit the size of the selective separation unit. By elsewhere, this depropanizer 45 provides good flexibility to produce either only crude oil or simultaneously liquefied gases and crude oil.

Afin de vérifier les performances du procédé selon l'invention, un exemple est donné ci-après à titre non limitatif.In order to verify the performance of the process according to the invention, an example is given below by way of illustration limiting.

EXEMPLE:EXAMPLE:

Le présent exemple vise à comparer les performances du procédé selon l'invention avec celles de la technique antérieure mise en oeuvre.This example aims to compare performance of the method according to the invention with those of the technique previous implementation.

Pour la technique mise en oeuvre antérieurement à l'invention, on installe à la sortie du puits d'extraction, un système d'au moins trois ballons de flash permettant de décomprimer le pétrole brut natif, avec des départs de vapeurs de décompression chargées essentiellement de gaz tels que l'azote, le gaz carbonique et d'hydrocarbures en C1 et C2 pour le premier ballon, d'hydrocarbures plus lourds pour les autres ballons. Si on prend le cas particulier du champ de Palanca, le pétrole brut natif sort avec une pression de 40 bars, à une température d'environ 48°C et un débit d'environ 350t/h (tonne/heure). Dans le premier ballon de décompression, la pression est ramenée à 27 bars, les gaz vaporisés sont évacués du ballon, puis conduits à la torche pour être brûlés, tandis que le pétrole brut décomprimé est dirigé vers un second ballon de décompression. Dans ce second ballon, le pétrole brut est décomprimé de 27 à 6 bars; comme précédemment les gaz vaporisés sont envoyés à la torche et le pétrole brut décomprimé est envoyé dans un troisième et dernier ballon dans lequel sa pression est ramenée à 1,2 bar.For the technique implemented prior to the invention, at the outlet of the extraction well, a system of at least three flash balloons is installed making it possible to decompress native crude oil, with departures of decompression vapors charged essentially gases such as nitrogen, carbon dioxide and C 1 and C 2 hydrocarbons for the first balloon, heavier hydrocarbons for the other balloons. If we take the specific case of the Palanca field, the native crude oil comes out with a pressure of 40 bars, at a temperature of around 48 ° C and a flow rate of around 350t / h (ton / hour). In the first decompression balloon, the pressure is reduced to 27 bars, the vaporized gases are evacuated from the balloon, then led to the torch to be burned, while the decompressed crude oil is directed to a second decompression balloon. In this second balloon, the crude oil is decompressed from 27 to 6 bars; as before, the vaporized gases are sent to the torch and the decompressed crude oil is sent to a third and final balloon in which its pressure is reduced to 1.2 bar.

Pour la présente invention, le pétrole brut natif envoyé dans l'enceinte 1 est décomprimé de 40 à 27 bars, seuls les hydrocarbures gazeux en C1 et C2 sont vaporisés et évacués vers la torche pour y être brûlés avec un débit de 37t/h. Le pétrole brut additionné du liquide d'absorption chargé d'hydrocarbures en C3, C4 et C5 est évacué de l'enceinte 1 à un débit de 382t/h et une température de 48°C. Il est refroidi jusqu'à 40°C dans l'échangeur 8, puis est introduit dans la colonne de distillation. Le pétrole brut stabilisé est recueilli à une température de 117°C, à la pression atmosphérique et à un débit de 293t/h par le conduit 9 à la sortie de la colonne. La tension de vapeur Reid du recycle, dans la partie médiane de la colonne, est de l'ordre de 0,69 bar à 38°C et la pression dans la colonne est de 8,5 bars.For the present invention, the native crude oil sent to enclosure 1 is decompressed from 40 to 27 bars, only the gaseous hydrocarbons of C 1 and C 2 are vaporized and discharged towards the torch to be burned there with a flow rate of 37 t / h. The crude oil added with the absorption liquid loaded with C 3 , C 4 and C 5 hydrocarbons is discharged from the enclosure 1 at a flow rate of 382 t / h and a temperature of 48 ° C. It is cooled to 40 ° C in the exchanger 8, then is introduced into the distillation column. The stabilized crude oil is collected at a temperature of 117 ° C, at atmospheric pressure and at a flow rate of 293 t / h through line 9 at the outlet of the column. The Reid vapor pressure of the recycle in the middle of the column is of the order of 0.69 bar at 38 ° C and the pressure in the column is 8.5 bar.

Le tableau ci-après rassemble les taux de récupération des hydrocarbures de C4 à C7 vaporisables pour le procédé de stabilisation correspondant à la technique antérieure (A) et le procédé de stabilisation selon l'invention (X). A X N2 10-5 0 CO2 1.5 0 C1 0.06 0 C2 2.6 0.02 C3 17.43 36.76 C4 49.8 93.81 C5 77.65 98.42 C6 94.56 98.66 C7 99.6 99.78 C8 100 100 C9 100 100 C10 100 100 C11 + 100 100 Eau 67,7 67.7 The table below shows the recovery rates of vaporizable C 4 to C 7 hydrocarbons for the stabilization process corresponding to the prior art (A) and the stabilization process according to the invention (X). AT X N 2 10 -5 0 CO 2 1.5 0 C 1 0.06 0 C 2 2.6 0.02 C 3 17.43 36.76 C 4 49.8 93.81 C 5 77.65 98.42 C 6 94.56 98.66 K 7 99.6 99.78 C 8 100 100 C 9 100 100 C 10 100 100 C 11 + 100 100 Water 67.7 67.7

On constate que les taux de récupération de composés hydrocarbonés selon la présente invention sont largement supérieurs à ceux de la technique antérieure. La quasi totalité des hydrocarbures valorisables en C3 + sont récupérés, pour une tension de vapeur Reid de 0,69 bar.It is found that the recovery rates of hydrocarbon compounds according to the present invention are much higher than those of the prior art. Almost all of the C 3 + recoverable hydrocarbons are recovered, for a Reid vapor pressure of 0.69 bar.

Claims (28)

  1. Process for stabilizing a native crude oil at the outlet of a well comprising a decompression stage consisting of partially degassing and decanting part of the extracted edge water and a separation stage consisting of distilling the said crude oil under pressure, the said process being characterized in that during the course of the decompression stage, the vaporized C4 to C7 hydrocarbons are absorbed in an absorption liquid which is then mixed with the said degassed oil, and in that during the course of the separation stage the said mixture is introduced into the median part ot a distilling column and distilled in at least two cuts, of which one is a gaseous cut of C1 to C5 hydrocarbons recovered at the head of the column, and one is a stabilized crude oil cut recovered below the point of injection of the native crude oil into the column.
  2. Process according to Claim 1, characterized in that the operations of degassing, absorption, mixing and decanting take place simultaneously in the same vessel, or in separate vessels.
  3. Process according to Claims 1 and 2, characterized in that the absorption liquid is introduced in a counter-current to the gaseous flow in order to trap the degassed C4 to C7 hydrocarbons during the decompression of the native crude oil.
  4. Process according to Claims 1 to 3, characterized in that the absorption liquid is a hydrocarbon of the group constituted by the distillation cuts of the stabilized crude oil and the stabilized crude oil itself.
  5. Process according to Claims 1 to 4, characterized in that the native crude oil is decompressed so as to reduce the pressure in a ratio of between 1 and 7 corresponding to the decompression rate.
  6. Process according to Claims 1 to 5, characterized in that the gaseous cut is separated selectively into two fractions, one consisting of the C3-light hydrocarbons, the other of the C4, C5 hydrocarbons and part of the C3 hydro-carbons.
  7. Process according to Claims 1 to 6, characterized in that only the fraction containing the C4 and C5 hydro-carbons is recovered, then condensed and finally re-injected at the head of the column.
  8. Process according to Claims 1 to 7, characterized in that the selective separation of the gaseous cut is achieved by a process selected from the group consisting of cryogenics, adsorption/desorption of these gases, and the separation of the gases on a membrane.
  9. Process according to Claims 1 to 8, characterized in that the fraction containing C3 to C5 hydocarbons is de-propanized.
  10. Process according to Claims 1 to 9, characterized in that the native crude oil is distilled in two cuts, the said gaseous cut at the head of the column and the cut of stabilized crude oil at the base of the column, part of the cut of stabilized crude oil being vaporized then re-injected at the base of the column.
  11. Proccss according to Claims 1 to 9, characterized in that the native crude oil entering the distillation column is distilled in three cuts, a gaseous cut of C1 to C5 hydrocarbons drawn off at the head of the column, then a cut of stabilized crude oil drawn off in the median part of the column, and finally a heavy cut of hydrocarbons, drawn off at the base of the column, consisting predominantly of hydrocarbons having at least eight carbon atoms per molecule.
  12. Process according to Claim 11, characterized in that a part of the said heavy cut is recycled as adsorption liquid in the decompression stage and the other part is vaporized then re-injected at the base of the column.
  13. Process according to Claims 11 and 12. characterized in that part of the cut of stabilized crude oil is vaporized and re-injected into the median part of the column above its draw-off point.
  14. Proccss according to Claims 11 to 13, characterized in that the internal pressure of the distilling column is between 4 bars and 15 bars.
  15. Apparatus implementing the process according to Claims 1 to 14, characterized in that it includes a partial decompression unit (1) for the native crude oil consisting of a closed vessel having at the head an infeed pipe (8) for a gas absorption liquid, and a distilling column (2) comprising an infeed pipe (7) for the charge of crude oil after decompression to be distilled, and at least two draw-off pipes for the gaseous hydrocarbon cut at the head of the column (11), and for the cut of crude oil (9) below the point of injection of the crude oil into the column.
  16. Apparatus according to Claim 15, characterized in that the column is connected at the head of the column to at least one selective separation circuit (13) by the draw-off pipe (11) for the gaseous cut and by an injections pipe for the predominantly C4 and C5 liquid hydrocarbons (18), which is located below the draw-off point of the said gaseous cut in the column.
  17. Apparatus according to Claims 16 to 19, characterized in that the selective separation circuit comprises at least one gaseous hydrocarbon selective separator (13a or 13b or 13c) selected from the group of separators consisting of cryogenic groups, adsorption/desorption reactors, selective membrane separators, and at least one liquid gas condenser.
  18. Apparatus according to Claim 17, characterized in that the selective separation circuit comprises at least one adsorption/desorption reactor (13a or 13b or 13c) filled with at least one absorbent selected from the group consisting of active carbons, wool industry residues and molecular screens.
  19. Apparatus according to Claims 17 and 18, characterized in that the selective separation circuit comprises at least two active carbon reactors (13a, 13b or 13c) operating alternately for the continuous implementation of the phases of adsorption and desorption of the hydrocarbons.
  20. Apparatus according to Claims 16 to 19, charactcrizcd in that it comprises downstream of the selective separation circuit at least one de-propanizer.
  21. Apparatus according to Claims 15 to 20, characterized in that the partial decompression unit (1) for the native crude oil consists of a closed vessel in the shape of an ovoidal receiver (1a) comprising in its upper part an extension (1b) comparable to a distillation mini-column of at least two theoretical plates, the said vessel including an entry pipe for the native crude oil (3), a discharge pipe for the decanted water (5) in its lower part, an outlet pipe (7) for the decompressed crude oil with the addition of the absorption liquid charged with C4 to C7 hydrocarbons, and a discharge pipe (6) for the C1 and C2 light hydrocarbons at the upper end of the extension and an entry pipe (8) for the absorption liquid.
  22. Apparatus according to Claims 15 to 20, characterized in that the decompression unit consists of a partial decompression circuit for the native crude oil comprising a decompression vessel (31) for the native oil connected by a gas discharge pipe (33) to a separation-absorption column (35) for the degassed C1 to C7 hydrocarbons comprising a gas outlet pipe (36), an entry pipe for the absorption liquid (48) and an outlet pipe for the absorption liquid charged with C4 to C7 hydrocarbons (37), and by a discharge pipe for the decompressed crude oil (32) to a mixing/decanting vessel (38) comprising an entry pipe for the absorption liquid charged with C4 to C7 hydrocarbons (37), an outlet pipe for the decanted water (39) and an outlet pipe (7) for the mixture of crude oil/absorption liquid to be distilled.
  23. Apparatus according to Claims 15 to 22, characterized in that the draw-off pipe for the stabilized crude oil (9) is located at the base of the column.
  24. Apparatus according to Claim 23, characterized in that the distillation column (2) is connected at the base of the column to a circuit for recycling part of the stabilized crude oil, equipped with a reboiler, by the draw-off pipe for the stabilized crude oil (9) and by an injection pipe for the vaporized crude oil, located above the said draw-off pipe.
  25. Apparatus according to Claims 15 to 22, characterized in that the distilling column comprises at least three draw-off pipes, one (11) for the gaseous cut at the head of the column, then one (9) for the cut of stabilized crude oil in the median part of the column, and finally one (12) for the heavy cut of hydrocarbons at the base of the column.
  26. Apparatus according to Claim 25, characterized in that the draw off pipe (12) for the heavy cut of hydro-carbons located at the base of the column (2) is connected on the one hand to the entry pipe (8) for the absorption liquid into the vessel (1) of the decompression unit and on the other hand to the circuit for recycling part of the said heavy cut comprising a reboiler (19) and a pipe (20) for the injection of the heavy cut into the column (2) which is located above the draw-off point (24).
  27. Apparatus according to Claims 25 and 26, characterized in that the column (2) is connected in its median part to at least one circuit for recycling part of the stabilized crude oil, equipped with a reboiler (25), by a second draw-off pipe (24) arranged at the same level as the draw-off pipe (9) for the stabilized crude oil and by an injection pipe (26) for the vaporized crude oil located above the said second draw-off pipe (24).
  28. Apparatus according to Claims 25 to 27, characterized in that it comprises at least two exchangers, the first (22) being placed preferably on the pipe (21) leading the absorption liquid into the vessel, and the second (10) preterably on the discharge pipe for the stabilized crude oil.
EP94923753A 1993-07-30 1994-07-28 Method for stabilising crude oils at the outlet of a well, and device therefor Expired - Lifetime EP0662997B1 (en)

Applications Claiming Priority (3)

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FR9309459A FR2708663B1 (en) 1993-07-30 1993-07-30 Process for stabilizing crude oils at the outlet of the extraction well and its implementation device.
FR9309459 1993-07-30
PCT/FR1994/000950 WO1995004116A1 (en) 1993-07-30 1994-07-28 Method for stabilising crude oils at the outlet of a well, and device therefor

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FR (1) FR2708663B1 (en)
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WO2012127295A1 (en) * 2011-03-18 2012-09-27 Ngl Tech Sdn. Bhd. A process for the recovery of crude
RU2465304C1 (en) * 2011-08-12 2012-10-27 Виктор Александрович Крюков Method of gas-saturated oil stabilisation
RU2553734C1 (en) * 2014-10-07 2015-06-20 Открытое акционерное общество "Татнефть" им. В.Д. Шашина Oil treatment method
US10287509B2 (en) 2016-07-07 2019-05-14 Hellervik Oilfield Technologies LLC Oil conditioning unit and process
RU2650247C1 (en) * 2017-09-28 2018-04-11 Андрей Владиславович Курочкин System of preparation and transportation of high-viscosity oil (options)
CA3173974A1 (en) * 2021-02-08 2022-08-11 Pioneer Energy, Inc System and method for oil production equipment that minimizes total emissions
US11725152B2 (en) 2021-06-02 2023-08-15 Maze Environmental Llc System and method of reducing emissions and increasing swell in an oil conditioning process
US20230347263A1 (en) * 2022-04-28 2023-11-02 Bell Engineering, Inc. Oil Vacuum Stabilizer
US11878260B1 (en) 2022-07-30 2024-01-23 Chevron U.S.A. Inc. Three phase separation in a distillation column

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FR2708663B1 (en) 1995-10-20
ATE174950T1 (en) 1999-01-15
NO309196B1 (en) 2000-12-27
EP0662997A1 (en) 1995-07-19
RU2135545C1 (en) 1999-08-27
OA10141A (en) 1996-12-18
RU95108236A (en) 1996-12-10
US5645692A (en) 1997-07-08
WO1995004116A1 (en) 1995-02-09
FR2708663A1 (en) 1995-02-10
DE69415488D1 (en) 1999-02-04
NO951186L (en) 1995-03-28
NO951186D0 (en) 1995-03-28

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