CN101735776B - Low-toxicity or nontoxic multi-functional drilling fluid finishing agent - Google Patents

Abstract

The invention relates to a low-toxic or non-toxic multi-functional drilling fluid treatment agent for oil and gas field drilling operations. It is non-polluting and non-toxic to the environment, and has the functions of preventing collapse, plugging, reducing water loss, protecting well walls, protecting oil and gas layers, and having no fluorescence. The technical plan is: first put water into the reaction tank, slowly add dispersant MV-CMC and gel protectant JT ₈₈₈ in the circulation, add emulsifier OP-10 once after dissolving, circulate for 10 minutes, slowly add liquid paraffin, After adding, emulsify for 30 minutes; then add defoamer YHP-008, and continue to circulate for 5-10 minutes; finally add 36% formaldehyde as a preservative, and recirculate for 5 minutes to obtain the low-toxic or non-toxic product of the present invention. Multifunctional drilling fluid treatment agent. This treatment agent is used in water-based drilling fluids, especially polymer drilling fluids, which can effectively improve the quality of water-based drilling fluid mud cakes and reduce water loss. It can be widely used in drilling operations.

Description

A low-toxic or non-toxic multifunctional drilling fluid treatment agent

technical field

The invention relates to a water-based drilling fluid used in drilling operations in oil and gas fields, in particular to a low-toxic or non-toxic multifunctional drilling fluid treatment agent for polymer drilling fluid.

Background technique

With the development of drilling technology, higher and higher requirements are put forward for the properties and performance of drilling fluid. With the increasingly stringent environmental regulations, the oil industry is urged to use less toxic oil-based drilling fluids and toxic water-based drilling fluids. As an alternative, low-toxic or non-toxic water-based drilling fluids and fake oil-based drilling fluids (such as synthetic-based drilling fluids) are used. Since the base fluids of synthetic-based drilling fluids are mainly synthetic hydrocarbons, they can be degraded aerobically and remain on the beach for many years, slowly affecting the environment; they can also be degraded anaerobically, causing severe impacts on the environment in the short term , Whether it can be accepted by environmental protection in the end, the prospect is not optimistic. Moreover, the cost of synthetic-based drilling fluid is currently at least three times higher than that of oil-based drilling fluid, and it is quite difficult to promote and use it in China.

A safer and more realistic approach is to use non-toxic water-based drilling fluids to avoid environmental issues from the start. However, when selecting a drilling fluid system, not only environmental requirements but also technical requirements must be considered. At present, oil well operations in the world are facing new challenges, that is, how to produce more oil and gas while reducing costs? The emergence of horizontal wells, branch wells, multi-bottom wells and slimhole drilling technologies provide effective means to achieve the above objectives. It enables some oil fields that are uneconomical to be exploited by other methods to be further developed, thereby greatly improving the rate of return on investment. However, so far, non-toxic, non-polluting or even low-toxic single agents are rare, and even if there are, they cannot meet environmental protection requirements. Judging from the current use of water-based drilling fluids, drilling fluids and their filtrates have more or less toxicity problems, and farmers are often reprimanded and punished. Coupled with strict monitoring of environmental regulations, drilling fluid technology is forced to Develop in the direction of low (no) toxicity. It can not only meet the current cost acceptance of drilling fluid, but also basically meet the discharge requirements. At the same time, it can achieve low friction and pressure loss, good thermal stability, excellent hydraulic properties, strong shale inhibition, and wall-building properties due to water loss. Good, large pollution tolerance, good compatibility with treatment agents, protection of oil and gas layers and other demanding requirements, and at the same time can better cooperate with geological logging to obtain accurate data, first develop a low-toxic or non-toxic multi-functional drilling Liquid treatment agent is a major event that is urgently expected at present and even in the future.

Contents of the invention

The present invention uses C ₁₂ -C ₁₈ straight-chain alkanes-liquid paraffin as the main raw material, adopts the principle of dispersion and aggregation balance, and synthesizes a low-toxic or non-toxic multifunctional drilling fluid treatment agent MFA-2 (full name is Multi-Function Additive-2), this treatment agent is non-toxic, non-polluting and environmentally friendly as a single agent, which can largely enable the drilling and completion fluid system to achieve low (non-)toxic and environmental protection requirements, while not affecting geological logging . Low-toxic or non-toxic multifunctional drilling fluid treatment agent MFA-2 is different from toxic deformable asphalt materials and low (non-)toxic polymer fluid loss reducers. (No) fluorescence, low (non-)toxic, environmentally friendly, inert, plugging, lubricating and other functions, it is a promising substitute for current asphalt products (including sulfonated asphalt, oxidized asphalt, oil-modified asphalt, emulsified asphalt, etc.) . At the same time, its particles can be deformed under certain temperature and pressure. When used in combination with non-toxic rigid ultra-fine calcium carbonate, it can implement effective temporary plugging and protect reservoirs. It is a promising substitute for asphalt and oil-soluble resins and The additive of choice for reservoir protection.

The object of the present invention is: in order to make the drilling fluid treatment agent non-polluting, non-toxic and easy to clean the environment, and at the same time have the functions of anti-collapse, plugging, protection of the well wall and oil and gas layers, reduction of water loss, and no fluorescence. Low or non-toxic multifunctional drilling fluid treatment agent.

In order to achieve the above object, the technical solution of the present invention is: a low-toxic or non-toxic multifunctional drilling fluid treatment agent, characterized in that: the components and contents of the raw materials used to prepare the drilling fluid treatment agent are as follows, wherein the quality of the content The unit is grams.

Water H ₂ O Potable water 100

Liquid paraffin C ₁₂ -C ₁₈ straight chain alkanes 65-70

Dispersant Carboxymethylcellulose Medium Viscosity Code MV-CMC 2-4

Protective agent acrylic acid and acrylamide copolymer code JT ₈₈₈ 1.5-4

Emulsifier Octylphenol Polyoxyethylene Ether-10 Code OP-10 3-5

Defoamer Polyethers Code YHP-008 1.5-4

Preservatives Formaldehyde≥36% 1-2

The preparation method is: first put 100g of water into the reaction tank, slowly add the dispersant MV-CMC2-4g and the protective agent JT ₈₈₈ 1.5-4g in the circulation; after it is completely dissolved, add the emulsifier OP-103- 5g, after circulating for 10 minutes, slowly add 65-70g of liquid paraffin, emulsify for 30 minutes after adding, take a sample and add to water and stir until the liquid paraffin can be dispersed in water; then add defoamer YHP-0081.5-4g at one time, and then Continue to circulate for 5-10 minutes, take a sample and add it to water and stir until the sample can be dispersed in water without foaming; finally add 1-2g of 36% formaldehyde at one time, and recirculate for 5 minutes to obtain this low-toxic or non-toxic product. The multi-functional drilling fluid treatment agent product, code-named MFA-2.

The liquid paraffin used in the above preparation method is 300 ^# liquid paraffin, C ₁₂ -C ₁₈ straight-chain alkanes, boiling range 200-300°C, density ρ 0.833-0.855, aromatics content ≤ 0.65%; emulsifier OP-10 temperature resistance 200°C , content ≥ 98%.

The water-soluble non-fluorescent defoamer YHP-008, dispersant MV-CMC, glue protectant JT ₈₈₈ , and preservative 36% formaldehyde used in the above preparation method are all products sold on the market. When purchasing, they must be inspected strictly according to industry standards or enterprise standards. Qualified persons can use it. See Table 1 for details.

Table 1 Production of low-toxic or non-toxic multifunctional drilling fluid treatment agent MFA-2 basic raw material list

product name code name level Indicator requirements Manufacturer water H ₂ O tap water drinking water   Local Water Company Dispersant MV-CMC Industrial grade Qualified according to the standard inspection Luzhou Chemical Plant Protective agent JT ₈₈₈ Industrial grade Qualified according to the standard inspection Sichuan Chengdu Dedao Industrial Co., Ltd. ^* Emulsifier OP-10 Industrial grade Qualified according to the standard inspection Henkel (Chengdu Office) Liquid paraffin -CH ₂ -CH ₂ - industrial grade 300 ^# liquid paraffin, boiling range ≥ 200 ℃ Jingmen Petrochemical General Plant (Chengdu Office, Yanshikou) Defoamer YHP-008 industrial grade Non-fluorescence, water soluble Chengdu Jinniu Drilling Fluid Material Factory Preservatives HCHO Industrial grade ≥36% Chengdu Chemical Store

Compared with the prior art, the present invention has the following beneficial effects: (1) This product is a special-purpose deformable soft particle plugging and multi-functional drilling fluid treatment agent for drilling fluid systems, with a temperature resistance of 150°C, especially for water-based drilling fluids. It is a polymer drilling fluid, used as filler particles to improve particle gradation, thereby effectively improving the quality of water-based drilling fluid mud cake and reducing fluid loss; It has anti-collapse and plugging functions and protects the well wall; (3) the product has low or no fluorescence and does not affect geological logging, and can be used in all production wells and exploration wells; (4) The product is non-polluting, non-toxic and easy to clean, and can be widely used in drilling operations.

Description of drawings

Fig. 1 is a production flow chart of the drilling fluid treatment agent of the present invention. In the figure: 1. Reaction tank, 2. Multi-stage pump, 3. Gear pump, 4. Charging barrel, 5. Inlet pump pipe, 6. Outlet pump pipe, 7. Fixed cement board, 8. Shade slope (30～ 40°), 9. Circulation flow direction, 10. Valve.

Detailed ways

Example 1: Preparation method of multifunctional drilling fluid treatment agent MFA-2

First put 100g of water into the reaction tank 1, start the multi-stage pump 2, open the valve 10, the water enters the reaction tank 1 through the pump pipe 6 according to the circulation flow direction 9 from the inlet pump pipe 5, and slowly adds 3g of dispersing Agent MV-CMC and 2g gel protecting agent JT ₈₈₈ ; after being completely dissolved, add 3.75g emulsifier OP-10 at one time, start the multistage pump 2 and slowly add 68g liquid paraffin after 10 minutes of circulation, emulsify for 30 minutes after adding, Add the sample into water and stir until the liquid paraffin can be dispersed in water; then add 2g of defoamer YHP-008 at one time, and continue to circulate for 5-10 minutes, add the sample into water and stir until the sample can be dispersed in water without foaming ; Finally, add 1g of 36% formaldehyde at one time and recirculate for 5 minutes to obtain the low-toxic or non-toxic multifunctional drilling fluid treatment agent product MFA-2 of the present invention. Then start the gear pump 3, and the product enters the charging barrel 4, and the product is shipped out of the factory. During production, the above-mentioned raw material consumption is doubled.

Example 2: Effect of MFA-2 in drilling fluid (see Table 2, Table 3)

Table 2 MFA-2 drilling fluid properties

Note: 1. The original slurry is 4% Anqiu secondary soil slurry. 2. Temperature measurement: 25°C.

Table 3 Other characteristics of MFA-2 drilling fluid

Note: 1. Lubrication coefficient is measured by extreme pressure lubrication instrument; 2. Plugging capacity is measured by sand packing method, the condition is 500Psi (600Psi). 80℃/30min, and then the permeability K is measured with clean water under different pressures _w ; 3. The recovery rate R ₄₀ is selected from 6-10 mesh Sichuan red layer soil, and the result is over 40 mesh.

It can be seen from the results in Table 2 and Table 3 that MFA-2 has a good fluid loss reduction effect, and the reduction rate can reach about 50% (addition amount 3%). MFA-2 is added into the original slurry as soft deformable particles, which can effectively seal the filling layer. If the original slurry is completely filtered off, the permeability of clear water is ∞, but after adding 3% MFA-2 products, the permeability is very low, which can be seen , MFA-2 has a strong plugging ability, which can effectively achieve the purpose of plugging and preventing collapse; after adding 3% MFA-2 to the original slurry, the recovery rate of Sichuan red bed soil can be increased by 1 to 2 times, and it has strong suppression ability . From the median particle size, it can be seen that the particle size of MFA-2 is mainly within 10 μm, and its median particle size is as high as 63%. It is beneficial to wellbore stability and protection of oil and gas layers. At the same time, MFA-2 has excellent lubricity and has little effect on the rheology of drilling fluid. According to the Petroleum and Natural Gas Industry Standard SY/T5664-94 of the People's Republic of China (shale inhibitor sulfonated bitumen FT1 for drilling fluid), MFA-2 is evaluated. The high temperature and high pressure drop water loss function of this product (150°C/30min) can reach the level of sulfonated bitumen FT1 level, temperature resistance up to 150°C.

Example 3: Fluorescence level, toxicity of MFA-2

Weigh 0.5g of the sample into a clean test tube, add 5ml of chloroform, stir slowly for 5 minutes, compare it with the standard colorimetric tube under the irradiation of a fluorescent lamp, and determine the fluorescence level of MFA-2. The measurement result is level 1, which can be seen The fluorescence level of MFA-2 is very low, far less than level 3, and it is a non-fluorescent product (the fluorescence levels of sulfonated asphalt HL-II and SAS detected by the same method are much higher than level 10, up to level 14), therefore, MFA -2 added to drilling fluid has no effect on geological logging, and can be used in all production wells and exploration wells.

Using GB/T13267-91 "Determination of Acute Toxicity of Water Quality Substances to Freshwater Fish", the acute toxicity of MFA-2 to goldfish was evaluated. This study was completed by the Sichuan Provincial Environmental Monitoring Center Station, and the evaluation was a static water test. The dilution water was tap water that had been placed for 24 hours, with a pH value of 6.5 and a dissolved oxygen of 8.33mg/l. Test fish domesticated 7d, healthy, active, body color is shiny. The body length is 4.0-4.5cm, the weight is 1±0.1g, and the fish load in the test water is 1g fish/liter of water. The LC _{50 of} the multifunctional drilling fluid treatment agent MFA-296h is 2990 mg/l, which indicates that the multifunctional drilling fluid treatment agent MFA-2 is a low (non-)toxic and environmentally friendly product.

From above-mentioned examples and overall efficiency, the production method of product MFA-2 of the present invention is economical, simple and convenient, stable in properties, is the best multifunctional product for drilling fluid, shows excellent low toxicity or nontoxicity, low (no) fluorescence, Environmentally friendly, deformable soft particles are inert, plugging, improving mud cake quality, reducing water loss, protecting well walls and oil and gas layers, etc., and can be widely used in drilling operations.

Claims (3)

1. a low toxicity or nontoxic multifunctional well-drilling liquid treating agent, it is characterized in that: it is as follows to prepare the raw materials used component of this additive for drilling fluid and content, and wherein the mass unit of content is gram,

Water H ₂O tap water 100;

Whiteruss C ₁₂-C ₁₈Straight-chain paraffin 65-70;

Sticking code name MV-CMC 2-4 in the dispersion agent carboxymethyl cellulose;

Colloid protecting resistance vinylformic acid and acrylamide copolymer code name JT ₈₈₈1.5-4;

Emulsifying agent octyl phenol Soxylat A 25-7-10 code name OP-10 3-5;

Defoamer polyethers code name YHP-008 1.5-4;

Sanitas formaldehyde 〉=36% 1-2;

Its preparation method is: first 100g water is put in the retort, slowly added dispersion agent MV-CMC 2-4g and colloid protecting resistance JT in the circulation ₈₈₈1.5-4g; Until completely dissolved, disposable adding emulsifier op-10 3-5g circulated after 10 minutes, slowly added whiteruss 65-70g, added rear emulsification 30 minutes, and sampling is added to the water stirring, until whiteruss can disperse in water; Then disposable adding defoamer YHP-008 1.5-4g continued circulation 5-10 minute again, and sampling is added to the water stirring, until sample can disperse in water and be non-foaming; The formaldehyde 1-2g of last property adding 36%, recirculation 5 minutes gets product low toxicity or nontoxic multifunctional well-drilling liquid treating agent.

2. described multifunctional well-drilling liquid treating agent according to claim 1, it is characterized in that: preparing the raw materials used whiteruss of this additive for drilling fluid is 300 ^#Whiteruss, boiling range 200-300 ℃, density p 0.833-0.855, aromaticity content≤0.65%; 200 ℃ of used emulsifier op-10 temperature resistances, content 〉=98%.

3. described multifunctional well-drilling liquid treating agent according to claim 1, it is characterized in that: it is water-soluble without fluorescent reagent, dispersion agent MV-CMC, colloid protecting resistance JT preparing the raw materials used defoamer YHP-008 of this additive for drilling fluid ₈₈₈, sanitas 36% formaldehyde is on the market sell goods, strictly by industry standard or enterprise's mark check, eligible could use when purchasing.

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