阅读说明：本技术 一种用于油基钻井液的固井冲洗液及其制备和使用方法 (Well cementation flushing fluid for oil-based drilling fluid and preparation and application methods thereof ) 是由 吴蔓莉 饶辰威 徐梦媛 姜鑫煜 于 2019-11-26 设计创作，主要内容包括：本发明公开了一种用于油基钻井液的固井冲洗液及其制备和使用方法,包括淡水、非离子表面活性剂一、非离子表面活性剂二、正盐助溶剂及酸式盐助溶剂；非离子表面活性剂一采用脂肪醇聚氧乙烯醚类非离子表面活性剂,非离子表面活性剂二采用壬基酚聚氧乙烯醚类非离子表面活性剂；非离子表面活性剂二具有良好的乳化性能,亲水基端易吸附在油水界面、套管及井壁表面；非离子表面活性剂一作为冲洗液主剂,有良好的润湿性、发泡性、去污力和乳化力,有较高的去脂能力、抗硬水力,易生物降解,配伍性良好；正盐助溶剂和酸式盐助溶剂盐用于对两种非离子表面活性剂进行助溶,同时增强了对钻井液和油基泥饼的洗脱能力；安全性高,配方简单,成本低,绿色环保。(The invention discloses a well cementation flushing fluid for oil-based drilling fluid and a preparation and use method thereof, wherein the well cementation flushing fluid comprises fresh water, a first nonionic surfactant, a second nonionic surfactant, a normal salt cosolvent and an acid salt cosolvent; the nonionic surfactant I is fatty alcohol polyoxyethylene ether nonionic surfactant, and the nonionic surfactant II is nonylphenol polyoxyethylene ether nonionic surfactant; the nonionic surfactant II has good emulsifying property, and hydrophilic base ends are easily adsorbed on an oil-water interface, a sleeve and the surface of a well wall; the non-ionic surfactant I is used as a main agent of the flushing fluid, has good wettability, foamability, detergency and emulsifying power, has higher degreasing capability and hard water resistance, is easy to biodegrade and has good compatibility; the normal salt cosolvent and the acid salt cosolvent are used for assisting in dissolving two nonionic surfactants, and the elution capacity of the drilling fluid and the oil-based mud cake is enhanced; high safety, simple formula, low cost and environmental protection.)

1. A well cementation flushing fluid for an oil-based drilling fluid is characterized by comprising the following components in parts by mass: 100 parts of fatty alcohol vinyl ether nonionic surfactant: 0.625-12.5 parts of nonylphenol polyoxyethylene ether nonionic surfactant: 0.625-12.5 parts of normal salt cosolvent: 0.125-0.5 parts of acid salt cosolvent: 0.125-0.5 portion.

2. A cementing flush fluid for an oil-based drilling fluid according to claim 1, wherein the fatty alcohol polyoxyethylene ether-based nonionic surfactant has an HLB value of 12 to 12.5.

3. A cementing flush fluid for an oil-based drilling fluid according to claim 1, wherein the nonylphenol polyoxyethylene ether nonionic surfactant has an HLB value of from 8.6 to 12.

4. The cementing flushing fluid for oil-based drilling fluids of claim 1, wherein the normal salt co-solvent is one of potassium carbonate, sodium carbonate and calcium chloride.

5. The cementing wash fluid for an oil-based drilling fluid of claim 1, wherein the acid salt co-solvent is one of sodium bicarbonate, disodium hydrogen phosphate, and potassium dihydrogen phosphate.

6. The cementing flush fluid for an oil-based drilling fluid of claim 1, wherein the cementing flush fluid for an oil-based drilling fluid has a pH of 7.5 to 9.6.

7. A method of preparing a cementing flush fluid for an oil-based drilling fluid according to any one of claims 1 to 6, comprising the steps of:

step 1, adding a normal salt cosolvent into water, and stirring until the normal salt cosolvent is dissolved to obtain a clear solution;

step 2, adding an acid salt cosolvent into the clear solution, and stirring until the acid salt cosolvent is dissolved to obtain a uniformly mixed solution;

step 3, adding nonylphenol polyoxyethylene ether nonionic surfactant into the uniformly mixed solution obtained in the step 2, and uniformly stirring to obtain a milky solution to obtain a component I;

and 4, adding the fatty alcohol vinyl ether nonionic surfactant into the first component, and stirring until the mixture is uniformly mixed to obtain the well cementation flushing fluid for the oil-based drilling fluid.

8. The method for preparing a well cementation flushing fluid for an oil-based drilling fluid according to claim 7, wherein in the step 1, a high-speed dispersion machine is adopted for stirring, the stirring speed is 50-200rpm, and the stirring time is 10-30 min.

9. The method for preparing a well cementation flushing fluid for an oil-based drilling fluid as claimed in claim 7, wherein in the step 3, the stirring speed is 200-500rpm, and the stirring time is 5-30 min; in step 4, the stirring speed is 200-500rpm, and the stirring time is 5-30 min.

10. The use method of the cementing washing fluid for the oil-based drilling fluid, which is described in any one of claims 1 to 6, is characterized in that the cementing washing fluid for the oil-based drilling fluid is diluted 1 to 20 times by using water, and the diluted use amount is 1.5 to 30 percent.

Technical Field

The invention relates to the technical field of oil field chemistry of petroleum drilling engineering, in particular to an oil-based drilling fluid well cementation flushing fluid and a preparation method thereof.

Background

The oil-based drilling fluid has strong adhesive force on the casing wall and the well wall due to high viscosity and small low shear rate, so that a high-elasticity gel structure is formed. The structure always changes the two interfaces into oleophilic state, increases the flowing consistency of cement slurry and seriously influences the replacement efficiency of the cement slurry in the well cementation process.

The flushing fluid is an important means for improving the well cementation quality, and at present, oil-based drilling fluid used at home and abroad has various well cementation flushing fluids, but has higher relative price and more complex components, and causes certain influence on the environment after being used. With the increasing requirement of environmental protection, the novel environment-friendly glass has the advantages of excellent research and development performance, environmental protection, no harm to human bodies, stable temperature and very important practical application value.

Disclosure of Invention

Aiming at the technical problems in the prior art, the invention aims to provide a well cementation flushing fluid for an oil-based drilling fluid and a preparation and use method thereof, so as to solve the technical problems that the oil-based drilling fluid is complex in components and has great harm to the environment in the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a well cementation flushing fluid for an oil-based drilling fluid, which comprises the following components in parts by mass: 100 parts of fatty alcohol vinyl ether nonionic surfactant: 0.625-12.5 parts of nonylphenol polyoxyethylene ether nonionic surfactant: 0.625-12.5 parts of normal salt cosolvent: 0.125-0.5 parts of acid salt cosolvent: 0.125-0.5 portion.

Further, the HLB value of the fatty alcohol polyoxyethylene ether nonionic surfactant is 12-12.5.

Further, the HLB value of the nonylphenol polyoxyethylene ether nonionic surfactant is 8.6 to 12.

Furthermore, the normal salt cosolvent adopts one of potassium carbonate, sodium carbonate and calcium chloride.

Furthermore, the acid salt cosolvent adopts one of sodium bicarbonate, disodium hydrogen phosphate and potassium dihydrogen phosphate.

Further, the pH of the cementing flushing fluid for the oil-based drilling fluid is 7.5-9.6.

The invention also provides a preparation method of the well cementation flushing fluid for the oil-based drilling fluid, which comprises the following steps of:

step 1, adding a normal salt cosolvent into water, and stirring until the normal salt cosolvent is dissolved to obtain a clear solution;

step 2, adding an acid salt cosolvent into the clear solution, and stirring until the acid salt cosolvent is dissolved to obtain a uniformly mixed solution;

step 3, adding nonylphenol polyoxyethylene ether nonionic surfactant into the uniformly mixed solution obtained in the step 2, and uniformly stirring to obtain a milky solution to obtain a component I;

and 4, adding the fatty alcohol vinyl ether nonionic surfactant into the first component, and stirring until the mixture is uniformly mixed to obtain the well cementation flushing fluid for the oil-based drilling fluid.

Further, in the step 1, a high-speed dispersion machine is adopted for stirring, the stirring speed is 50-200rpm, and the stirring time is 10-30 min.

Further, in the step 3, the stirring speed is 200-500rpm, and the stirring time is 5-30 min; in step 4, the stirring speed is 200-500rpm, and the stirring time is 5-30 min.

The invention also provides a use method of the well cementation flushing fluid for the oil-based drilling fluid, and when the well cementation flushing fluid is used, the well cementation flushing fluid for the oil-based drilling fluid is diluted by 1-20 times by using water, and the use amount of the diluted well cementation flushing fluid is 1.5-30%.

Compared with the prior art, the invention has the beneficial effects that:

the invention provides a well cementation flushing fluid for an oil-based drilling fluid, which adopts a nonylphenol polyoxyethylene ether nonionic surfactant, wherein the nonylphenol polyoxyethylene ether nonionic surfactant has good emulsifying property, and the hydrophilic radical end of the nonylphenol polyoxyethylene ether nonionic surfactant is easily adsorbed on an oil-water interface, a sleeve and the surface of a well wall; the fatty alcohol-polyoxyethylene ether nonionic surfactant is used as a main agent of the flushing fluid, has good wettability, foamability, detergency and emulsifying power, has higher degreasing capability and hard water resistance, is easy to biodegrade, and has good compatibility and stability; the normal salt cosolvent and the acid salt cosolvent are used for assisting in dissolving the fatty alcohol polyoxyethylene ether nonionic surfactant and the nonylphenol polyoxyethylene ether nonionic surfactant, so that mutual solubility of the two main agents in water is realized, and the elution capability of the drilling fluid and the oil-based mud cake is enhanced; the flushing liquid disclosed by the invention is high in safety, simple in formula, low in cost and environment-friendly; the cleaning effect on the mud cake of the oil-based drilling fluid seriously polluted is good, the displacement efficiency and the cementing property of a cement sheath can be improved, and the well cementation quality is ensured.

The invention also provides a preparation method of the well cementation flushing fluid for the oil-based drilling fluid, which has the advantages of low economic cost, simple preparation process, good solubilizing and clearing effects on the drilling fluid or the mud in a short time, small influence by the viscosity of the oil-based base fluid, high emulsifying efficiency on the oil-based base fluid or the oil-based drilling fluid and strong clearing capacity on the oil-based mud; the system is stable and has no obvious change along with the temperature change; and the washing liquid is friendly to human body and environment, has good biodegradability, and is an environment-friendly high-efficiency washing liquid.

The well cementation flushing fluid for the oil-based drilling fluid is simple in component and low in cost, and the price of raw materials for preparing 1 ton of flushing fluid is about 0.2 ten thousand yuan; the flushing efficiency is high and can reach more than 98 percent, and the flushing device has good flushing performance. The used flushing liquid is green, environment-friendly and nontoxic, and is beneficial to environmental protection; the flushing fluid has stable performance, higher demulsification voltage and good rheological property, and meets the performance requirement of oil-based drilling flushing.

Detailed Description

The technical solutions of the embodiments of the present invention are explained and illustrated below, but the following embodiments are only preferred embodiments of the present invention, and not all of them. Based on the embodiments in the implementation, other embodiments obtained by those skilled in the art without any creative effort belong to the protection scope of the present invention.

The invention provides a well cementation flushing fluid for an oil-based drilling fluid, which comprises the following components in parts by mass: 100 parts of fatty alcohol vinyl ether nonionic surfactant: 0.625-12.5 parts of nonylphenol polyoxyethylene ether nonionic surfactant: 0.625-12.5 parts of normal salt cosolvent: 0.125-0.5 parts of acid salt cosolvent: 0.125-0.5 part; wherein, the HLB value of the fatty alcohol polyoxyethylene ether nonionic surfactant is 12-12.5, and the HLB value of the nonylphenol polyoxyethylene ether nonionic surfactant is 8.6-12; the normal salt cosolvent adopts one or two of potassium carbonate, sodium carbonate and calcium chloride; the acid salt cosolvent adopts one or two of sodium bicarbonate, disodium hydrogen phosphate and potassium dihydrogen phosphate; the pH value of the well cementation flushing fluid for the oil-based drilling fluid is 7.5-9.6.

The invention also provides a preparation method of the well cementation flushing fluid for the oil-based drilling fluid, which comprises the following steps of:

step 1, adding a normal salt cosolvent into water, stirring by using a high-speed dispersion machine until the normal salt cosolvent is dissolved, wherein the stirring speed is 50-200rpm, and the stirring time is 10-30min, so as to obtain a clear solution;

step 2, adding an acid salt cosolvent into the clear solution, and stirring until the acid salt cosolvent is dissolved, wherein the stirring speed is 50-200rpm, and the stirring time is 10-30min, so as to obtain a uniformly mixed solution;

step 3, adding nonylphenol polyoxyethylene ether nonionic surfactant into the mixed solution, and stirring until the mixed solution is uniform, wherein the solution is milky white, the stirring speed is 200-500rpm, and the stirring time is 5-30min, so as to obtain a component I;

step 4, adding the fatty alcohol vinyl ether nonionic surfactant into the component one, and stirring until the mixture is uniformly mixed, wherein the stirring speed is 200-500rpm, and the stirring time is 5-30 min; and obtaining the well cementation flushing fluid for the oil-based drilling fluid.

When the well cementation flushing fluid for the oil-based drilling fluid is used, the well cementation flushing fluid for the oil-based drilling fluid is diluted by 1-20 times by using water, and the usage amount of the diluted flushing fluid is 1.5-30%.