阅读说明：本技术 一种稠油水平井用耐高温堵剂及堵水方法 (High-temperature-resistant plugging agent for thick oil horizontal well and water plugging method ) 是由 刘江玲 黄腾 门琦淏 黄小雷 李尚莹 于 2019-11-28 设计创作，主要内容包括：本发明提供了一种稠油水平井用耐高温堵剂及堵水方法。该耐高温堵剂包括水玻璃、尿素、填充剂,其中,所述水玻璃和尿素的体积比为1:2-2.2,所述填充剂占水玻璃和尿素总重量的20-25％。所述耐高温堵剂在井筒中的残留堵剂能够通过冲洗作业处理掉,有效保证施工的安全性,简化了施工过程。本发明还提供了一种稠油水平井堵水方法,该方法以上述耐高温堵剂作为近井段塞,以氮气泡沫凝胶堵剂作为远井段塞,利用两种堵剂间的协同配合保障水平井的堵水效果,与其他耐高温堵剂的堵水方法相比,本发明提供的耐高温堵剂及堵水方法具有材料来源广泛、施工安全简单、堵水效果好、应用前景广阔的特点。(The invention provides a high-temperature-resistant plugging agent for a thick oil horizontal well and a water plugging method. The high-temperature-resistant plugging agent comprises water glass, urea and a filling agent, wherein the volume ratio of the water glass to the urea is 1: (2-2.2), and the filling agent accounts for 20% -25% of the total weight of the water glass and the urea. The residual plugging agent of the high-temperature-resistant plugging agent in a shaft can be removed through flushing operation, the construction safety is effectively guaranteed, and the construction process is simplified. The invention further provides the water plugging method for the thick oil horizontal well. According to the method, the high-temperature-resistant plugging agent serves as a near-well slug, a nitrogen foam gel plugging agent serves as a far-well slug, and the water plugging effect of the horizontal well is guaranteed through cooperation of the two plugging agents. Compared with water plugging methods of other high-temperature-resistant plugging agents, the high-temperature-resistant plugging agent and the water plugging method have the advantages that the material source is wide, construction is safe and simple, the water plugging effect is good, and the application prospect is wide.)

1. The high-temperature resistant plugging agent for the thick oil horizontal well comprises water glass, urea and a filler, wherein the volume ratio of the water glass to the urea is 1:2-2.2, and the weight of the filler is 20-25% of the total weight of the water glass and the urea.

2. The high temperature resistant plugging agent of claim 1, wherein the modulus of said water glass is 3-3.5.

3. The high temperature resistant plugging agent of claim 1, wherein said filler comprises bentonite powder.

4. The high temperature resistant blocking agent of any one of claims 1-3, wherein the water glass, urea and filler are subjected to a gel-forming curing reaction to form the high temperature resistant blocking agent, wherein the temperature of the gel-forming curing reaction is greater than 80 ℃.

5. The high temperature resistant blocking agent of claim 4, wherein the curing time of the high temperature resistant blocking agent is greater than 48 hours.

6. A water plugging method for a thick oil horizontal well, wherein the method uses the high-temperature resistant plugging agent as claimed in any one of claims 1 to 5 as a near well slug and uses a nitrogen foam gel plugging agent as a far well slug.

7. The method of claim 6, wherein the nitrogen foam gel plug comprises nitrogen and foam gel plug in a volume ratio of 50-60: 1;

the nitrogen is under the condition of standard atmospheric pressure;

the foamed gel plugging agent comprises the following components in percentage by weight, based on 100 percent of the total weight of the foamed gel plugging agent: 0.8-1% of partially hydrolyzed polyacrylamide, 1.3-1.5% of formaldehyde, 0.4-0.6% of hydroquinone, 0.8-0.8% of AE 99010.6, 1.2-1.4% of petroleum sulfonate and the balance of water.

8. The method as claimed in claim 7, wherein the partially hydrolyzed polyacrylamide has a degree of hydrolysis of 10-35%, and a molecular weight of 800-2500.

9. The method according to any one of claims 6 to 8, wherein the working pressure at the time of injecting the nitrogen foam gel blocking agent is 17 to 20 MPa.

10. The method as claimed in claim 9, wherein the injection amount of the foam gel plugging agent is 1000-1500 and the injection amount of the nitrogen gas is 6-9 ten thousand.

11. The method according to claim 6, wherein the injection amount of the high temperature resistant plugging agent is calculated according to a cylinder volume method, and the calculation formula is as follows:

Q＝πR²hФ，

wherein Q is the injection amount of the high-temperature resistant plugging agent, and the unit is a square; pi is the circumference ratio, and is taken as 3.14; r is the treatment radius, and the unit is m; h is the length of a horizontal well section, and the unit is m; phi is the oil layer porosity, the unit is,

preferably, the treatment radius is 0.6-0.8 m.

12. The method as claimed in claim 6 or 11, wherein the injection amount of the high temperature blocking agent is 100-150 square.

Technical Field

The invention relates to the technical field of oil exploitation, in particular to a high-temperature-resistant plugging agent for a thick oil horizontal well and a water plugging method.

Background

The horizontal well mainly takes the encryption among heavy oil wells, the secondary evaluation of low-grade reserves in old areas, the layered development and the secondary development as the main parts, and has the characteristics of complex geological conditions, multiple oil reservoir types, wide application types and the like. However, with the increase of the production degree, the formation pressure is reduced, the problem of side bottom water invasion is gradually aggravated, the phenomena of high water content of produced liquid and even water flooding are common, and the water flooding problem is gradually expanded to adjacent wells on the same floor, so that water is produced in peripheral vertical wells or horizontal well areas. After the water breakthrough occurs in the horizontal well, the oil production of the oil well is greatly reduced, the water treatment cost is increased, and if no proper remedial measure is available, the well must be shut down too early, so that the waste of the productivity occurs. The horizontal well water plugging technology becomes a first measure for solving the problem.

The high-temperature resistant plugging agent adopted at present is generally a resin fly ash plugging agent or a dual-excitation inorganic gel plugging agent, the curing or gelling time is short, the plugging agent remained in a shaft needs to be drilled and ground subsequently, the construction process is complicated, and the measure cannot be implemented in a damaged well or a small cased well after overhaul. Therefore, the research on the special high-temperature-resistant plugging agent for the horizontal well has important significance for meeting the water plugging requirement of the thickened oil horizontal well.

Disclosure of Invention

In order to solve the problems, the invention aims to provide a high-temperature-resistant plugging agent for a thick oil horizontal well and a water plugging method. The high-temperature-resistant plugging agent and the water plugging method have the characteristics of wide raw material source, safe and simple construction, good water plugging effect, wide application prospect and the like.

In order to achieve the purpose, the invention provides a high-temperature-resistant plugging agent for a thick oil horizontal well, which comprises water glass, urea and a filler, wherein the volume ratio of the water glass to the urea is 1:2-2.2, and the filler accounts for 20-25% of the total weight of the water glass and the urea.

In the high-temperature resistant blocking agent, the modulus of the water glass is preferably 3 to 3.5.

In the above high-temperature resistant plugging agent, preferably, the filler includes bentonite powder.

In the above high temperature resistant blocking agent, preferably, the water glass, urea and the filler are subjected to a gelling and curing reaction to form the high temperature resistant blocking agent, and the reaction temperature of the gelling and curing reaction is greater than 80 ℃.

In the above high temperature resistant blocking agent, preferably, the curing time of the high temperature resistant blocking agent is more than 48 hours.

The invention also provides a water plugging method for the thickened oil horizontal well, which takes the high-temperature resistant plugging agent as a near well slug and takes the nitrogen foam gel plugging agent as a far well slug.

In a specific embodiment of the invention, the far well slug is a first injection slug and the near well slug is a second injection slug.

In the above method, preferably, the nitrogen foam gel blocking agent comprises nitrogen and a foam gel blocking agent in a volume ratio of 50-60: 1. Wherein the nitrogen is under standard atmospheric pressure conditions;

the foamed gel plugging agent comprises the following components in percentage by weight, based on 100 percent of the total weight of the foamed gel plugging agent: 0.8-1% of partially hydrolyzed polyacrylamide, 1.3-1.5% of formaldehyde, 0.4-0.6% of hydroquinone, 0.6-0.8% of AE9901 (the main component is a nonionic surfactant of polyoxypropylene polyoxyethylene block polyether), 1.2-1.4% of petroleum sulfonate and the balance of water.

In the above-mentioned foam gel blocking agent, preferably, the degree of hydrolysis of the partially hydrolyzed polyacrylamide is 10-35%, and the molecular weight of the partially hydrolyzed polyacrylamide is 800-2500.

In the above method, preferably, the nitrogen foam gel plugging agent is injected under a working pressure of 17 to 20MPa to displace 0.5 mass% polyacrylamide solution. More preferably, the injection amounts of the foam gel plugging agent and the nitrogen are respectively adjusted according to the construction pressure, and the specific adjustment mode is that if the injection pressure is lower than 17MPa, the injection amounts of the foam gel plugging agent and the nitrogen are correspondingly increased; on the contrary, if the injection pressure is higher than 20MPa, the injection amount of the foam gel plugging agent and the nitrogen is correspondingly reduced, wherein the injection amount of the foam gel plugging agent is 1000-1500 square, and the injection amount of the nitrogen is 6-9 ten thousand square.

In the above method, preferably, the injection amount of the high temperature resistant plugging agent is calculated according to a cylinder volume method, and the calculation formula is as follows: q ═ pi R²h phi, wherein Q is the injection quantity of the high-temperature resistant plugging agent, and the unit is a square; pi is the circumference ratio, and is taken as 3.14; r is the treatment radius, and the unit is m; h is the length of a horizontal well section, and the unit is m; phi is the oil layer porosity in%. More preferably, the treatment radius is 0.6 to 0.8 m.

In the above method, preferably, the injection amount of the high temperature resistant plugging agent is 100-150 square.

The invention has the beneficial effects that:

1. the water plugging method for the thickened oil horizontal well provided by the invention takes the nitrogen foam gel plugging agent as a far well slug, and plays a role in regulating and plugging a water outlet channel; the high-temperature-resistant plugging agent is used as a near well slug, subsequent injection of steam is isolated, the far well slug is protected, the plugging strength of the plugging agent is improved, and the water plugging effect of the horizontal well is guaranteed.

2. The high-temperature-resistant plugging agent provided by the invention can be used for removing the residual plugging agent in a shaft through flushing operation after construction is finished, so that the plugging strength is improved, drilling and grinding procedures are omitted, the risk of measures is greatly reduced, and the construction process is simplified.

3. Compared with other water plugging methods of high-temperature resistant plugging agents, the high-temperature resistant plugging agent and the water plugging method provided by the invention have the characteristics of wide material source, safe and simple construction, good water plugging effect and wide application prospect.

Detailed Description

The technical solutions of the present invention will be described in detail below in order to clearly understand the technical features, objects, and advantages of the present invention, but the present invention is not limited to the practical scope of the present invention.

Example 1

The embodiment provides a water plugging method for a thick oil horizontal well, which specifically comprises the following steps:

for a certain oilfield Dudu 32-xing H357 well (crude oil density at 20 ℃ is 1.01 g/cm)³The viscosity of the ground degassed crude oil at 50 ℃ is 96210mPa.s, the freezing point is 23 ℃, the wax content is 4.9%, and the colloid and asphaltene content is 49.04%. According to the classification standard of thick oil, the block belongs to super thick oil) water plugging construction, firstly, a water plugging pipe is utilized to inject 1200 square of foam gel plugging agent into an oil layer at the construction pressure of 17MPa, and 6 ten thousand square of nitrogen is used; then the injection amount is designed according to the treatment radius of 0.6m, and 100 parts of the high-temperature resistant plugging agent is injected at the construction pressure of 13 MPa.

The foam gel plugging agent comprises the following specific components by taking the foam gel plugging agent as 100 percent: 0.8% of partially hydrolyzed polyacrylamide, 1.3% of formaldehyde, 0.5% of hydroquinone, 99010.6% of AE, 1.2% of petroleum sulfonate and the balance of water, wherein the hydrolysis degree of the partially hydrolyzed polyacrylamide is 10-35%, and the molecular weight is 800-2500.

The high-temperature resistant plugging agent is prepared by mixing a mixture of 1:2 water glass (modulus is 3.2) and urea, and bentonite powder with weight of 20% of the total weight of the water glass and the urea, and the mixture is obtained by curing reaction for 70 hours at the temperature of more than 80 ℃.

Before the well measure, 22.3 tons of daily produced liquid and 0 ton of daily produced oil contain 99 percent of water; after the water shutoff measure is carried out, 21.5 tons of daily produced liquid and 10.3 tons of daily produced oil are produced, the water content is reduced to 52.1 percent, the production lasts for 259 days, and the oil is increased by comparison to 2667.7 tons.

Example 2

The embodiment provides a water plugging method for a thick oil horizontal well, which specifically comprises the following steps:

for a certain oilfield Dudu 813-Xingping 2 well (crude oil density at 20 ℃ is 1.0098g/cm³The viscosity of the ground degassed crude oil at 50 ℃ is 108880mPa.s, the freezing point is 26.1 ℃, the wax content is 2.3%, and the content of colloid and asphaltene is 51%. According to the classification standard of thick oil, the block belongs to super thick oil) water plugging construction, firstly, a water plugging pipe is utilized to inject 1500 square foam gel plugging agent and 9 ten thousand square nitrogen into an oil layer at 18MPa construction pressure; then the injection amount is designed according to the treatment radius of 0.76m, and 150 parts of the high-temperature resistant plugging agent is injected at the construction pressure of 14 MPa.

The foam gel plugging agent comprises the following specific components by taking the total weight of the foam gel plugging agent as 100 percent: 1% of partially hydrolyzed polyacrylamide, 1.5% of formaldehyde, 0.6% of hydroquinone, 99010.8% of AE, 1.4% of petroleum sulfonate and the balance of water, wherein the hydrolysis degree of the partially hydrolyzed polyacrylamide is 10-35% and the molecular weight is 800-2500.

The high-temperature resistant plugging agent is prepared by mixing a mixture of 1:2 water glass (modulus is 3.1) and urea, and bentonite powder with weight 23% of the total weight of the water glass and the urea, and the mixture is obtained through curing reaction for more than 80 hours and 72 hours.

23.6 tons of daily produced liquid, 2.4 tons of daily produced oil and 90 percent of water before the well measure; after the water shutoff measure is implemented, 20.7 tons of daily produced liquid and 9.6 tons of daily produced oil are produced, the water content is reduced to 53.6 percent, the production lasts for 532 days, and the oil is increased by comparison to 3830.4 tons.

The embodiment 1 and the embodiment 2 show that the high-temperature-resistant plugging agent and the water plugging method for the thick oil horizontal well, provided by the invention, can improve the plugging strength, effectively adjust the plugging of the thick oil well, simplify the construction process and greatly increase the oil yield of the thick oil well.