CN113698176A

CN113698176A - Method for preparing sintered bricks by using solid-phase wastes of offshore water-based drilling

Info

Publication number: CN113698176A
Application number: CN202111120073.0A
Authority: CN
Inventors: 刘文士; 何冬雪; 李茂川; 熊兴洋; 王波; 刘钰; 肖笑
Original assignee: Southwest Petroleum University
Current assignee: Southwest Petroleum University
Priority date: 2021-09-24
Filing date: 2021-09-24
Publication date: 2021-11-26

Abstract

The invention discloses a method for preparing a baked brick by using solid-phase waste of offshore water-based drilling, which comprises the following steps: (1) performing solid-liquid separation on the drilling mud and the waste drilling fluid of the offshore oil and gas field to obtain solid-phase waste, and transferring the solid-phase waste to land; (2) on land, crushing, drying, grinding and sieving solid-phase waste to obtain a powder sample with the particle size not more than 2 mm; (3) washing the powder sample by using deionized water as an extracting agent; (4) uniformly stirring and mixing the washed powder sample, the shale and the coal to obtain a mixed material; (5) adding water into the mixed material, stirring uniformly, then aging, and pressing the aged material into a green brick; (6) and drying the green brick, heating to 900-. The method can realize the resource utilization of the offshore drilling waste, avoid the occupation of land by the drilling waste and the environmental pollution, and promote the sustainable development of the offshore oil and gas field.

Description

Method for preparing sintered bricks by using solid-phase wastes of offshore water-based drilling

Technical Field

The invention relates to the technical field of resource utilization of drilling waste, in particular to a process method for preparing a building brick by using offshore water-based drilling solid-phase waste.

Background

The ocean contains rich oil gas resources, and the high-efficiency development of ocean oil gas has a decisive significance for relieving the energy crisis of China. In the process of drilling operation in an offshore oil and gas field, a large amount of solid-phase drilling wastes including waste drilling mud and drilling cuttings which may have biotoxicity or contain toxic and harmful substances such as inorganic salt, heavy metal and the like are inevitably generated, and if the solid-phase drilling wastes are directly discharged to the sea, the solid-phase drilling wastes can cause huge damage to the marine environment. Therefore, the offshore drilling cuttings are required to be transported to inland for disposal after being processed at sea. After the drilling solid phase is transported back to inland, not only a large amount of land resources are occupied, but also potential environmental safety hazards exist, and an effective tail end disposal process is urgently required to be explored.

The building material recycling path not only can realize the final treatment of the drilling solid phase, but also can change waste into valuable, generates certain economic benefit and accords with the treatment measures of the current national environmental protection and energy conservation policy. At present, the water-based drilling solid phase resource utilization technologies mainly comprise the following technologies: (1) the water-based well drilling solid phase is solidified and then used for building roadbed materials, or is used for preparing baking-free bricks and then used for well site construction, and the method has the defect that pollutants are not removed, so secondary pollution is easily caused. (2) Water-based drilling solids are used for the local production of cement, but because of the high sintering temperatures required to produce cement, the manufacturing costs are high and uneconomical. (3) And (3) treating the water-based drilling solid phase by adopting a biological resource treatment method. The method conforms to an energy-saving and environment-friendly disposal and utilization method, is more beneficial to ecological restoration, but cannot treat the large amount of water-based drilling solid phase at present on a large scale due to a long treatment period. (4) The method can realize harmless treatment of the water-based drilling solid phase and optimal environmental benefit and economic benefit, and land oil and gas fields also use the process to treat the waste drilling solid phase. However, the offshore drilling solid waste cannot be completely handled by the land-based process due to the high salt content of the solid waste. The invention provides a method for preparing sintered bricks by utilizing marine wastes on the basis of fully analyzing the basic properties of the marine drilling wastes, and provides a method for effectively solving the technical problem of resource disposal after the solid-phase recovery of the water-based drilling of the marine oil and gas field comes ashore.

Disclosure of Invention

The invention aims to provide a method for preparing a baked brick by using offshore water-based drilling waste.

The invention provides a method for preparing a baked brick by a solid phase offshore water-based drilling well, which comprises the following steps:

(1) and carrying out solid-liquid separation on the drilling mud and the waste drilling fluid of the offshore oil and gas field to obtain solid-phase waste, bagging and transferring the solid-phase waste to land. Solid phase waste includes drill cuttings or filter cake. The drill cuttings are solid phases obtained by screening drilling mud (a mixture of drilling cuttings and waste drilling fluid generated in the drilling stage of offshore oil and gas exploitation) by using a vibrating screen. And flocculating and filter-pressing the liquid phase obtained by the vibrating screen and the waste drilling fluid to form blocky solid waste with low water content, namely the filter cake. And bagging the drill cuttings and the filter cakes respectively and transferring the drill cuttings and the filter cakes to land. In the subsequent steps (2) to (6), one of the drill cuttings and the filter cake may be selected to prepare the baked brick.

The filter cake and drill cuttings main chemistry is shown in table 1:

TABLE 1 Main chemical composition Table of drilling solid phase

The filter cake and the drill cuttings mainly contain SiO₂And Al₂O₃And the method has the basic elements for preparing the raw materials of the baked bricks. Meanwhile, the filter cake and the drill cuttings both contain higher Cl^-The method is obviously different from solid phase waste of onshore oil and gas field drilling, and Cl is contained in the baked brick^-The content has certain limit requirements, which limits the mixing amount of the offshore filter cake and the drill cuttings in the baked bricks.

(2) On land, solid-phase waste (drill cuttings or filter cakes) is crushed, dried, ground and sieved to obtain powder samples with the particle size not exceeding 2 mm. Crushing by a jaw crusher until the granularity is less than 5mm, drying until the water content is less than 5%, further grinding by a planetary ball mill, and sieving by a screen to obtain a powder sample with the fineness of not more than 2 mm.

(3) And (3) washing the powder sample by using deionized water as an extracting agent for removing chloride ions, wherein the liquid-solid ratio of the deionized water to the powder sample is 4, and the washing time is 30 min. The water washing process is a process method for transferring soluble substances into water under the action of centrifugal force by using water as a medium, can effectively remove free chloride ions contained in solid-phase drilling cuttings of water-based drilling and filter cakes by reasonably designing the water-solid ratio and the stirring time, and reduces the influence of the chloride ions on the sintered bricks.

(4) And uniformly stirring and mixing the washed powder sample, the shale and the coal according to the ratio of 20-30:65-75:5 to obtain a mixed material. Two preferred embodiments: firstly, if the drill cuttings are selected to prepare the baked brick, the optimal mixing ratio of the drill cuttings powder sample, the shale and the coal after water washing is 30:65: 5. Secondly, if a filter cake is selected to prepare the sintered brick, the optimal mixing ratio of the washed filter cake powder sample, the shale and the coal is 20:75: 5.

(5) Adding tap water into the mixture, wherein the water content is 14% of the mass of the mixture, uniformly stirring the mixture, aging and oxidizing the mixture for 24 hours, then putting the aged material into a metal mold of 40 x 160mm, keeping the pressure at 15MPa for 2 minutes, and pressing and forming to obtain a green brick. Aging for 24h can make the raw materials fully contact with water, enhance the plasticity of the mixed material and improve the green brick forming and surface smoothness.

(6) Firstly, putting a green brick into an electric heating thermostat, drying for 8 hours at the temperature of 105 +/-5 ℃, and removing the moisture of the green brick; and (3) sintering the dried green brick in a muffle furnace at the heating rate of 5 ℃/min to 900-class 1000 ℃, calcining at constant temperature for 3h, and naturally cooling to obtain the sintered brick.

Compared with the prior art, the invention has the advantages that:

1. the solid-phase waste (drilling cuttings/filter cakes) of the water-based drilling well, which is obtained after the drilling platform of the offshore oil and gas field is vibrated and filter-pressed, is used as the raw material of the baked brick, and shale and coal are supplemented, so that the waste recycling is realized, and the disposal problem after the marine water-based drilling well waste is recycled and ashed is solved.

2. Based on the high salt-containing characteristic of the solid-phase waste of offshore drilling, pollutants such as chloride, oil-containing pollutants and the like are removed by combining a water washing process and a sintering process, the environmental safety of the sintered brick is ensured, and secondary pollution is avoided.

3. By analyzing the physical and chemical properties of the solid-phase waste of the offshore drilling, the solid-phase waste contains mineral components which are beneficial to the properties of sintered products. The sintered brick of the invention adopts filter cakes and drill cuttings to replace partial raw materials, and the main mineral phase for preparing the sintered brick by offshore water-based drilling solid phase is quartz (SiO)₂) Albite (NaAlSi)₃O₈) Hematite (Fe)₂O₃) Anorthite (CaAl)₂Si₂O₈) And barite (BaSO)₄). The minerals form a framework structure of the baked brick, and the fused liquid phase is filled in the interior of the brick body and jointly acts to endow the baked brick with strength. During sintering, the minerals with poor thermal stability are decomposed to generate a large amount of amorphous substances, and then the amorphous substances participate in solid phase reaction, and a new mineral phase is formed after recrystallization. The feldspar mineral is melted at high temperature, which is beneficial to promoting the melting of quartz and other minerals, and the molten glass phase is filled between the quartz and the pores in the brick body, so that the compactness of the brick body is enhanced, and the performance of the sintered brick is improved. The performance of each building material of the sintered brick prepared by the method meets the MU15 grade requirement in 'sintered common bricks' (GB/T5101-2017). Taking a crushed sample of the sintered brick, preparing a leaching solution according to a horizontal oscillation method of a solid waste leaching toxicity leaching method (HJ557-2010), and testing that all indexes meet the standard requirements of Integrated wastewater discharge Standard (GB 8978-1996).

4. The method not only can prepare the qualified building brick, but also effectively solves the problem of safe and environment-friendly disposal of the tail end of the offshore drilling waste, realizes the resource utilization of the waste drilling material, and ensures that the waste drilling material does not occupy the land and pollute the environment.

5. The preparation method is scientific and reasonable in preparation process, relatively low in cost, simple and feasible in treatment steps, and the disposal rate of the drilling cuttings/filter cakes is improved. Can realize large-scale production treatment and produce economic benefits.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.

Drawings

FIG. 1 is a schematic view of a process for preparing a baked brick according to the present invention.

FIG. 2 is a graph showing the effect of the liquid-solid ratio and the water washing time on the removal of chloride ions.

Detailed Description

The preferred embodiments of the present invention will be described in conjunction with the accompanying drawings, and it will be understood that they are described herein for the purpose of illustration and explanation and not limitation.

Example 1

The method for preparing the baked brick by the solid-phase waste of the offshore water-based drilling comprises the following steps:

(1) firstly, drilling wastes (drilling rock debris and waste drilling fluid mixture generated in the drilling stage of offshore oil and gas exploitation) in an offshore oil and gas field are screened by a vibrating screen to obtain a solid phase as drilling cuttings, and the drilling cuttings are used for preparing sintered bricks.

(2) And (4) crushing and drying the drill cuttings, and then grinding and sieving to obtain a drill cuttings powder sample (the particle size is not larger than 2 mm).

(3) And washing the chlorine ions in the powder sample under the conditions of a liquid-solid ratio of 2 and water washing time of 10, 20, 30 and 60 min.

(4) And uniformly stirring and mixing the drill cutting powder, the shale and the coal which are washed with water according to the ratio of 10:85: 5.

(5) Adding tap water into the mixture, wherein the water amount is 14% of the mass of the mixture, uniformly stirring the materials, then aging for 24 hours, pressing the aged materials into green bricks, keeping the forming pressure at 15MPa for 2 minutes.

(6) Drying the formed green brick at the temperature of 105 +/-5 ℃ for 8h, heating to 900 ℃ at the heating rate of 5 ℃/min, sintering at high temperature, preserving heat for 3h, and cooling to room temperature to obtain a finished sintered brick.

Example 2

(1) firstly, drilling wastes (drilling rock debris and waste drilling fluid mixture generated in the drilling stage of offshore oil and gas exploitation) in an offshore oil and gas field are primarily screened by a vibrating screen to obtain a solid phase which is drill cuttings. And preparing the baked brick by adopting the drill cuttings.

(3) Washing the chloride ions in the powder sample under the conditions of liquid-solid ratio of 4, water washing time of 10 min, 20 min, 30min and 60 min;

(4) uniformly stirring and mixing the drill cutting powder, the shale and the coal after water washing according to the ratio of 10:85: 5;

(5) adding tap water into the mixture, wherein the water amount is 14% of the mass of the mixture, uniformly stirring the materials, then aging for 24 hours, pressing the aged materials into green bricks, keeping the forming pressure at 15MPa for 2 minutes;

(6) drying the formed green brick at the temperature of 105 +/-5 ℃ for 8h, heating to 950 ℃ at the heating rate of 5 ℃/min for high-temperature sintering, preserving heat for 3h, and cooling to room temperature to obtain a sintered brick finished product.

Example 3

(3) And cleaning the chloride ions in the powder sample under the conditions of liquid-solid ratio of 6, water washing time of 10 min, 20 min, 30min and 60 min.

(6) Drying the formed green brick at the temperature of 105 +/-5 ℃ for 8h, heating to 1000 ℃ at the heating rate of 5 ℃/min, sintering at high temperature, preserving heat for 3h, and cooling to room temperature to obtain a finished sintered brick.

Example 4

(3) Washing the chloride ions in the powder sample under the conditions of liquid-solid ratio of 8, water washing time of 10 min, 20 min, 30min and 60 min;

(4) and uniformly stirring and mixing the drill cutting powder, the shale and the coal which are washed with water according to the ratio of 20:75: 5.

FIG. 2 shows the effect of different liquid-to-solid ratios and water wash times on chloride ion removal. As can be seen from FIG. 2, the content of chloride ions in the drill cuttings decreases with the increase of the water washing time, most of the chloride ions can be quickly washed and removed within 30min, and when the water washing time exceeds 30min, the chloride ions in the raw materials can be basically completely removed. As the liquid-solid ratio increased from 2 to 8, the chloride ion removal rate tended to increase overall. However, when the liquid-solid ratio exceeds 4, the overall removal rate of the chloride ions tends to be flat, which indicates that the removal of the chloride ions is facilitated by appropriately increasing the liquid-solid ratio. Therefore, the optimal water washing process is that the liquid-solid ratio is 4, and the water washing time is 30 min.

Example 5

Example 6

(4) and uniformly stirring and mixing the drill cutting powder, the shale and the coal which are washed with water according to the ratio of 30:65: 5.

Example 7

(1) and (2) flocculating and filter-pressing the liquid phase obtained by the vibrating screen in the step (1) in the embodiment 1 and the waste drilling fluid to form blocky solid waste with low water content, namely the filter cake. This example used a filter cake to prepare a sintered brick.

(2) And (3) crushing and drying the filter cake, and then grinding and sieving to obtain a filter cake powder sample (the particle size is not larger than 2 mm).

(4) And uniformly stirring and mixing the washed filter cake powder, the shale and the coal according to the ratio of 10:85: 5.

Example 8

(1) and (2) flocculating and filter-pressing the liquid phase obtained by the vibrating screen and the waste drilling fluid in the step (1) of the embodiment 1 to form blocky solid waste with low water content, namely the filter cake. This example used a filter cake to prepare a sintered brick.

(3) And washing the chlorine ions in the powder sample under the conditions of a liquid-solid ratio of 4 and water washing time of 10 min, 20 min, 30min and 60 min.

Example 9

(3) Cleaning chloride ions in the powder sample under the conditions of liquid-solid ratio of 6 and water washing time of 10 min, 20 min, 30min and 60 min;

Example 10

(4) and uniformly stirring and mixing the filter cake powder after water washing, the shale and the coal according to the ratio of 20:75: 5.

Example 11

(4) and uniformly stirring and mixing the filter cake powder after water washing, the shale and the coal according to the ratio of 30:65: 5.

Example 12

And (3) testing the performance of the sintered brick:

the test is carried out according to the relevant requirements in the national standard 'sintered common bricks' (GB/T5101-2017), and various performance parameters are shown in tables 2 and 3.

TABLE 2 sintered brick Performance Table prepared from drill cuttings of examples 1-6

TABLE 3 Performance Table of baked brick prepared from filter cakes of examples 7 to 12

As can be seen from tables 2 and 3, various performance indexes of the sintered brick obtained by the preparation method disclosed by the invention meet the requirements of the national standard 'sintered common brick' (GB/T5101-2017). Therefore, the method can prepare the solid-phase wastes (drilling cuttings and filter cakes) of the offshore water-based drilling into the baked bricks with good performance, thereby realizing resource utilization.

Leachate was prepared from the sintered bricks in examples 1 to 6 according to "solid waste leaching toxicity leaching method-horizontal oscillation method" (HJ557-2010) and "solid waste leaching toxicity leaching method-sulfuric acid-nitric acid method" (HJ/T299-2007), the concentrations of pollutants and heavy metals in the leachate were tested, and compared with "comprehensive wastewater discharge standard" (GB8978-1996) and "hazardous waste discrimination standard leaching toxicity discrimination" (GB5085.3-2007), the results showed that both the concentrations of pollutants and heavy metals in the leachate did not exceed the standard limits, indicating that the environmental performance of the sintered bricks was good.

Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A method for preparing a baked brick from solid-phase wastes of offshore water-based drilling is characterized by comprising the following steps:

(1) performing solid-liquid separation on the drilling mud and the waste drilling fluid of the offshore oil and gas field to obtain solid-phase waste, bagging and transferring the solid-phase waste to land;

(2) crushing, drying, grinding and sieving the solid-phase waste on land to obtain a powder sample with the particle size not more than 2 mm;

(3) washing the powder sample with deionized water as leaching agent to remove chloride ions, wherein the liquid-solid ratio of the deionized water to the powder sample is 4, and the washing time is 30 min;

(4) uniformly stirring and mixing the washed powder sample, the shale and the coal according to the ratio of 20-30:65-75:5 to obtain a mixed material;

(5) adding water into the mixed material, wherein the water amount is 14% of the mass of the mixed material, uniformly stirring the materials, aging and maintaining for 24 hours, and pressing the aged materials into green bricks;

(6) drying the green brick at the temperature of 105 +/-5 ℃ for 8h, heating to 900-1000 ℃ at the heating rate of 5 ℃/min, calcining at the constant temperature for 3h, and cooling to room temperature to obtain the sintered brick.

2. The method for preparing sintered bricks from solid-phase waste of offshore water-based drilling as claimed in claim 1, wherein in the step (2), the solid-phase waste is crushed in a jaw crusher to a particle size of less than 5mm, and then further ground by a planetary ball mill and sieved to obtain powder samples with a particle size of not more than 2 mm.

3. The method for preparing the baked brick from the solid-phase waste of offshore water-based drilling according to claim 1, wherein in the step (1), the solid-phase waste is drill cuttings or filter cakes; the drill cuttings are solid phases obtained by drilling mud after passing through a vibrating screen; filter pressing and dehydrating the liquid phase obtained by the vibrating screen and the waste drilling fluid to obtain a filter cake; respectively bagging the drill cuttings and the filter cakes and transferring the drill cuttings and the filter cakes to land; in the subsequent steps (2) to (6), one of the drill cuttings and the filter cake is selected to prepare the baked brick.

4. The method for preparing the baked brick from the solid-phase waste of offshore water-based drilling according to claim 3, wherein in the step (4), if the baked brick is prepared from the drill cuttings, the mixing ratio of the drill cuttings powder sample, the shale and the coal after washing is 30:65: 5.

5. The method for preparing the baked brick from the solid-phase waste of the offshore water-based drilling as claimed in claim 3, wherein in the step (4), if the baked brick is prepared by selecting the filter cake, the mixing ratio of the powder sample of the filter cake after washing, the shale and the coal is 20:75: 5.

6. The method for preparing a clinker brick from solid phase waste from offshore water-based drilling as set forth in claim 4 or 5, wherein in the step (5), the aged material is placed in a metal mold of 40 x 160mm and pressed to form.

7. The method for preparing the baked brick from the solid-phase waste of the offshore water-based drilling as claimed in claim 6, wherein the step (6) is specifically that the green brick is firstly put into an electric thermostat and dried for 8 hours under the condition of 105 +/-5 ℃ to remove the moisture of the green brick; and (3) sintering the dried green brick in a muffle furnace at the heating rate of 5 ℃/min to 900-class 1000 ℃, calcining at constant temperature for 3h, and naturally cooling to obtain the sintered brick.