CN1207483C

CN1207483C - Well completion formate liquid for well drilling

Info

Publication number: CN1207483C
Application number: CN 03101261
Authority: CN
Inventors: 宋瑞宏; 顾永福; 王淑华
Original assignee: Daqing Petroleum Administration Bureau
Current assignee: Daqing Petroleum Administration Bureau
Priority date: 2003-01-14
Filing date: 2003-01-14
Publication date: 2005-06-22
Anticipated expiration: 2023-01-14
Also published as: CN1425739A

Abstract

The present invention relates to a formate well completion liquid for well drilling, which belongs to the technical field of petroleum geological exploration and development. The formate well completion liquid solves the problem of heavy pollution of hydrocarbon zones of the existing well completion liquid for well drilling. The formate well completion liquid comprises the components of the following weight portions: 0.2 to 0.8 portion of salt resistant encapsulation agents, 1.5 to 5.5 portions of salt resistant depressants, 2 to 6.2 portions of collapse resistant agents, 1.7 to 6.8 portions of salt resistant plugging agents, 2.0 to 16.0 portions of formate, 0.5 share to 3.0 portions of salt resistant viscosity reductants and 67 to 87 portions of water. The formate well completion liquid has the characteristics that the completion liquid can protect the hydrocarbon zones and stabilize well walls. The formate well completion liquid has the advantages of stable performance, strong inhibition and no corrosiveness, and is beneficial to the smooth well drilling.

Description

The formates drill in fluid

Technical field:

The present invention relates to the used a kind of drill in fluid in petroleum geology exploration and development technique field, belong to the formates drill in fluid.

Background technology:

In drilling process; for guaranteeing drilling quality and completion quality; except needs use some special-purpose plant equipment; also need to use some special-purpose fluids; this fluid is exactly a drill in fluid; drill in fluid is to open oil reservoir to the used liquid of the overall process that brings in from brill, and it should satisfy the requirement of technology, also will protect oil reservoir conscientiously.Open the drill in fluid of oil reservoir as brill, should stabilizing borehole, have certain head of liquid, in order to stress evenly, prevent from that fluid from invading in the well to cause the well kick blowout; Good balance lateral pressure is arranged again, improve mud cake quality, keep wellbore stability, prevent differential sticking, reduce filtrate, stop solid phase to invade oil reservoir; To guarantee that also drilling cuttings and suspension are carried in the bottom-hole cleaning effectively.

More drill in fluid is the clear brine drill in fluid at present, common clear brine drill in fluid has ammonium chloride, calcium chloride, calcium bromide, zinc bromide etc., at the well control desired density, store and should meet the demands aspect the chemical compatibility between temperature required and drill in fluid and the stratum, otherwise need to proofread and correct.But in use, a little less than the drill in fluid inhibition, soil is joined slurry as needing, and as soil join slurry can't overcome as the thin colloidal nature of disperseing of soil particle and keep the hole stability of pulping section in the stratum, seriously polluted to the oil-gas Layer generation.

Drill in fluid uses both sexes compound ion and potassium ammonium polymer in addition, and its anti-collapse rejection is relatively poor, and the stabilizing borehole effect is bad, easily makes reservoir that soil lock or water lock take place, and is big to the reservoir damage caused degree.

Summary of the invention:

In order to overcome existing completion fluid oil-gas Layer is produced with serious pollution deficiency, the invention provides a kind of formates drill in fluid, this drill in fluid helps protecting oil-gas Layer and energy stabilizing borehole.

Adoptable technical scheme is: this drill in fluid comprises water, and each composition and proportioning are as follows by weight: 67～87 parts in 0.2～0.8 part of anti-salt coating agent, 1.5～5.5 parts, anti-collapse dose 2～6.2 parts of anti-salt inhibitors, 1.7～6.8 parts of anti-salt sealing agents, 2.0～16.0 parts of formates, 0.5～3.0 part of anti-salt thinner and water.

Above-mentioned anti-salt coating agent is the acrylamide sodium acrylate copolymer, its molecular weight is between 250～2,800,000, anti-salt inhibitor is an amide polymer, its molecular weight is between 700～8,000,000, anti-collapse dose is silicon humic-acid kind product, anti-salt sealing agent is to be to be the product of primary raw material with pitch and phenolic resins, and formates is organic sodium salt, sylvite, the cesium salt with hydroxy-acid group.

The beneficial effect of this scheme is: because this drill in fluid has selected for use formates as main component, solubility is big, and viscosity is low, the density height that can realize; Can improve simultaneously the temperature resistance ability of polymer, strong inhibition capability, non-corrosiveness, environmental sound; Do not need with as soil join slurry, the finely divided colloidal nature of soil particle and keep the hole stability of pulping section in the stratum as thoroughly having solved has suppressed the phenomenon that drilling cuttings disperses, so has helped reservoir protection and stabilizing borehole in drilling fluid.

The specific embodiment:

Below with the present invention is further illustrated:

This drill in fluid comprises water, and each composition and proportioning are as follows by weight: 67～87 parts in 0.2～0.8 part of anti-salt coating agent, anti-collapse dose 2～6.2 of anti-salt inhibitor 1.5～5.5 part, part, 1.7～6.8 parts of anti-salt sealing agents, 2.0～16.0 parts of formates, 0.5～3.0 part of anti-salt thinner and water.

Because having adopted formates is host,, otherwise will plays chemistry reflection with formates and fall flat so other above-mentioned composition all has anti-salt action.

Anti-salt coating agent is the acrylamide sodium acrylate copolymer, its molecular weight is between 250～2,800,000, anti-salt inhibitor is an amide polymer, its molecular weight is between 700～8,000,000, anti-collapse dose is to be primary raw material with pitch and phenolic resins, anti-salt sealing agent is a silicon humic-acid kind product, and formates is organic sodium salt, sylvite, the cesium salt with hydroxy-acid group.

Because anti-salt coating agent is by macromolecule polyalcohol acrylamide with anti-salt action characteristic and copolymer that PAA is formed, its molecular weight is between 250～2,800,000.This copolymer is a backbone, can wrap on the surface of landwaste, stops hydrone to enter landwaste; And anti-salt inhibitor is the amide polymer with salt resistance characteristic, by carbon carbochain group, sulfonic acid group, and amido is formed, its molecular weight is between 700～8,000,000, be by amide polymer sulfonation hydrolysis, under the effect of catalyzer, carry out polymerisation and generate, mainly be to suppress the drilling cuttings aquation to disperse, reduce the drilling fluid dehydration, and the group of amine can with the positively charged end generation suction-operated of clay particle, make the branch polymer be adsorbed on the surface of clay and glassware for drinking water has repulsive interaction, stop hydrone to enter clay particle, can guarantee the performance of this drill in fluid, satisfy its construction requirement; Anti-salt sealing agent is a primary raw material with pitch and phenolic resins, carry out sulfonating reaction by several alkyl on the pitch and phenolic resins, generate the adjustable asphalt product of softening point, have anti-collapse, leak-off falls, the effect of protection oil-gas Layer, so this drill in fluid has protective effect to oil-gas Layer; Anti-salt is silicon humic-acid kind product for anti-collapse dose, because the drill in fluid head of liquid greater than formation pressure, makes completion fluid permeate to reservoir, the filtrate of this infiltration is carried solid phase particles and directly entered rock core, forms filter cake, and the borehole wall has been played anti-collapse stabilization; The sylvite complex salt contains formate and the clay effect in the organic sodium salt, sylvite, cesium salt of hydroxy-acid group, can be adsorbed on the surface of clay, play the effect that stops hydrone to enter clay inside, solubility is big, viscosity is low, the density height that can realize has formed the high shale control agent of a kind of salinity; And can drilling speed be had a significant impact when drilling fluid viscosity is too high, have the phenomenon of bit freezing tool and the generation of other accident sometimes even also, therefore drilling fluid is controlled within certain range of viscosities, guarantee carrying out smoothly of wellbore construction.All all have anti-salt action in the mentioned component, otherwise will play chemistry reflection with formates and fall flat.

Can take following three kinds of schemes to describe, the effect parameter of each scheme is as follows:

As seen from the above table; this drill in fluid is owing to adopted formates; make this drill in fluid can meet the demands in well control desired density, the chemical compatibility that stores between temperature required and completion fluid and the stratum; improve the compatibility on filtrate and stratum, can realize protecting the effect of reservoir and stabilizing borehole.

Embodiment 1: use the drill in fluid of such scheme 1 that grand celebration Song Fang village 210-154 is carried out site operation, the result is a sealing hole diameter rule, and hole diameter is near straight line, average well amplification degree is less than 8%, well logging is success once, the cementing quality high-quality, and the density of drill in fluid is controlled at 1.20g/cm ³In, dehydration is less than 5ml, satisfy completion fluid at the well control desired density, store the requirement aspect the chemical compatibility between temperature required and completion fluid and the stratum, average oil production intensity 2.32t/d.m helps protecting the drill in fluid of reservoir, is suitable for applying.

Embodiment 2: use the drill in fluid of such scheme 2 that grand celebration Song Fang village 212-156 is carried out site operation, the viscosity of drilling fluid is controlled at less than 55g/cm ³Within, solids-carrying capacity is strong, sand return is effective, there is not the generation of bit freezing phenomenon, well logging is success once, and cementing quality reaches 92%, satisfy completion fluid at the well control desired density, store the requirement aspect the chemical compatibility between temperature required and completion fluid and the stratum, little to formation damage, help the anti-collapse and stable of the borehole wall.

Embodiment 3: the drill in fluid of use such scheme 3 is started 9-39 to grand celebration and has been carried out The field, the finishing drilling well depth is at 1595-1615 rice, crept into cycle 4-5 days, 36.2 meters/hour of drag bit rate of penetration average out to, PDC drill bit average rate of penetration is 20.1 meters/hour, 30.3 meters/hour of full well average rate of penetrations, compare with other well of same block, rate of penetration is suitable, interval isolation well rule, the well amplification degree helps guaranteeing cementing quality less than 6%.

Claims

1, a kind of used formates drill in fluid of petroleum geology exploration and development technique field that relates to comprises water, and it is characterized in that: each composition and proportioning are as follows by weight:

67～87 parts in 0.2～0.8 part of anti-salt coating agent, 1.5～5.5 parts, anti-collapse dose 2～6.2 parts of anti-salt inhibitors, 1.7～6.8 parts of anti-salt sealing agents, 2.0～16.0 parts of formates, 0.5～3.0 part of anti-salt thinner and water, wherein anti-salt coating agent is the copolymer of acrylamide and PAA, its molecular weight is between 250～2,800,000, anti-salt inhibitor is an amide polymer, its molecular weight is between 700～8,000,000, anti-collapse dose is silicon humic-acid kind product, anti-salt sealing agent is for being to be primary raw material with pitch and phenolic resins, and anti-salt thinner is the humic-acid kind product.

2, formates drill in fluid according to claim 1 is characterized in that: formates is organic sodium salt, sylvite, the cesium salt with hydroxy-acid group.