Integrated resin microemulsion dispersion system sand prevention method and device

Abstract

The invention discloses an integrated resin microemulsion dispersion system sand prevention method and device, and belongs to the technical field of petroleum well completion. The method comprises the six steps of resin microemulsion preparation, well washing operation, stratum pretreatment, resin microemulsion injection, well shut-in curing and liquid drainage production. The particle size of the prepared resin microemulsion is 150-350nm, and the solid content is 12%-15%; a well flushing fluid containing 0.5% of AEO-9 is used for well flushing, a pretreatment fluid containing 1% of mahogany petroleum sulfonate is used for stratum pretreatment, and both the well flushing fluid and the pretreatment fluid need to be replaced by a displacing fluid; and injecting the resin microemulsion by using a high-pressure plunger pump, closing the well, curing for 12-72 hours, opening the well, and discharging the liquid. According to the method, the process is simplified, the sand production amount after sand prevention is reduced by 96% or above, the permeability retention rate is 80% or above, the productivity recovery rate is increased by 20%-30% compared with that of traditional chemical sand prevention, the comprehensive cost is low, and the popularization value is high.

Description

Technical Field

[0001] This invention belongs to the field of oil well completion technology, specifically relating to an integrated resin microemulsion dispersion system for sand control and a device. Background Technology

[0002] In oil extraction, sand production from the reservoir is a key factor restricting the efficient and stable production of oil and gas wells. Sand particles enter the wellbore and surface equipment with the produced fluid, causing severe wear and tear on pumps, pipelines, and other equipment, increasing maintenance costs. At the same time, sand accumulation may block oil flow channels, reducing production or even leading to production shutdowns.

[0003] Existing sand control methods mainly include mechanical and chemical sand control. Mechanical sand control uses devices such as sand control screens and slotted liners to block sand particles, but its effectiveness in blocking fine sand particles is limited, and the devices are prone to clogging, requiring replacement later and increasing costs. Chemical sand control uses chemical agents to bind loose sand particles into a cementitious substance, but in existing chemical sand control processes, the chemical agents are mostly injected in stages (segmented injection), which is complex to operate, difficult to cope with complex downhole environments, has poor sand control effect, short effective period, and some agents can damage the oil reservoir, reduce permeability, and affect production.

[0004] Therefore, there is a need to develop an integrated, efficient, low-damage, low-cost, and easy-to-operate sand control method. Summary of the Invention

[0005] The purpose of this invention is to provide an integrated resin microemulsion dispersion system for sand control. Through a unique process, it effectively solves the sand production problem in oil and gas wells, improves the sand control effect, reduces damage to reservoir permeability, reduces costs, simplifies the construction process, meets the petroleum industry's demand for efficient sand control technology, and ensures efficient and stable production of oil and gas wells.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for sand control using an integrated resin microemulsion dispersion system includes the following steps: S1. Preparation of resin microemulsion: Select epoxy resin, add additive E and stir at a speed of 200-350 r / min for 15-20 min. Add pure water in stages and gradually increase the stirring speed to 1000 r / min. Then add curing agent and reinforcing agent and continue stirring to form a stable resin microemulsion with a particle size of 150-350 nm and a solid content of 12%-15%. S2. Well washing operation: Clean the wellbore with a well washing fluid containing 0.5% (by mass) fatty alcohol polyoxyethylene ether AEO-9. The fatty alcohol polyoxyethylene ether AEO-9 has the structural formula RO-(CH2CH2O)9H, where R represents C. 15 ~C 17The fatty alcohol groups are controlled at a flow rate of 3.5-5.5 m³ / h. Then, a portable turbidity analyzer with a range of 0-1000 NTU and an accuracy of 2% FS is used to detect the turbidity of the well washing fluid. The well washing is considered qualified when the turbidity of the outlet well washing fluid is lower than 20 NTU. S3. Formation pretreatment: Inject a pretreatment solution containing 1% petroleum sulfonate by mass, the amount of which is twice the volume of the resin emulsion, and the flow rate is 0.1-0.5 m³ / min. The liquid level at the end of the pretreatment solution section is injected to the top boundary of the sand control oil layer section. S4. Resin microemulsion injection: Injected using a high-pressure plunger pump at a pressure of 80-90% of the rock fracturing pressure in the oil reservoir, with an injection flow rate of 0.1-0.5 m³ / min and an injection volume V. f The formula is determined based on the oil layer thickness and porosity, and is as follows: ; Where ∅ is porosity, H is oil layer thickness, and r is sand control radius. The tail end of the sand control liquid is injected to the top boundary of the sand control oil layer section. S5. Well shut-in solidification: Close the wellhead valve for 12-72 hours and maintain the oil layer temperature at the original temperature ±3℃. S6. Fluid production: Start production for 1-5 days, controlling the bottom pressure differential to ≤3MPa. After 5 days, increase the fluid production rate and control the bottom pressure differential to ≤8MPa until the discharged fluid has no obvious solid particles and the flow rate is stable.

[0007] An integrated resin microemulsion dispersion system sand-proof device includes a stirrer. An explosion-proof stirring motor is mounted on the top of the stirrer. A high-pressure plunger pump is mounted on the left side of the stirrer. A pipe on the bottom left side of the stirrer connects to one end of a centrifugal pump. A pipe on the top of the centrifugal pump connects to one end of a Venturi jet injector. The other end of the Venturi jet injector is connected to the stirrer and a liquid outlet via a T-connector. A water inlet is connected to a pipe on the top right side of the stirrer. The explosion-proof stirring motor, high-pressure plunger pump, and centrifugal pump are all electrically connected to a temperature control system. The stirring speed of the stirrer is adjustable from 0 to 1500 r / min with a speed control accuracy of ±5 r / min. The temperature control system has a temperature control range of 0 to 100℃ with an accuracy of ±1℃.

[0008] Specifically, the epoxy resin is bisphenol A type, with the general molecular formula C0. 11 H 12 O3(C3H6O) n， Where n is the degree of polymerization, ranging from 2 to 5, and the purity is ≥97%; the auxiliary agent E is a compound of two surfactants A and B in a certain mass ratio, and the general molecular formula of surfactant A is C9H. 19 C6H4(OCH2CH2) 10 The molecular structure of surfactant OH,B is C 12 H25 SO4Na, A and B in a mass ratio of 2:1, and the amount of additive E added is 8%-12% of the epoxy resin mass; after adding pure water, the stirring speed is controlled by stepwise increase, with an increase of 100r / 5min, and the speed is gradually increased to 1000r / min in 5-7 times, with a total stirring time ≥90min.

[0009] Specifically, the purity requirements for the pure water are: conductivity of 30-50 μS / cm, and mass fraction of 82.5-85.9% of the total amount of resin microemulsion.

[0010] Specifically, after the epoxy resin microemulsion dispersion system is prepared, a portable laser particle size analyzer is used to detect the particle size distribution of the microemulsion, with a measurement range of 0-1000μm and an accuracy of 1%FS.

[0011] Specifically, the curing agent is a modified amine with a molecular structure containing ≥3 amine active groups; the amount of well-washing fluid used is twice the wellbore volume.

[0012] Specifically, the high-pressure plunger pump has a maximum working pressure ≥70MPa, a flow rate adjustment accuracy of ±0.3%FS, and an injection pressure fluctuation ≤±5% of the set pressure.

[0013] Specifically, the displacement fluid is active water containing 0.5% petroleum sulfonate by mass, and the amount used is 2-3 times the volume of the wellbore space.

[0014] Specifically, in the process of draining the liquid, the draining is considered complete when the mass ratio of solid particles in the drained liquid is less than 0.5%.

[0015] The beneficial effects of this invention are as follows: In terms of formulation, the resin microemulsion in this application is a stable and uniform dispersion system; in terms of injection, it eliminates the need for staged injection, simplifying the process and enhancing the effect. The resin microemulsion has a small particle size, allowing it to penetrate into the tiny pores of the oil layer, making close contact with sand particles and forming a continuous and robust cemented film network structure, effectively preventing sand particle migration. Tests show that sand output is reduced by more than 96% after sand control, reducing equipment wear and extending service life. The solid content of the raw materials after cementation is <15%, and the penetration retention rate is over 80%, minimizing damage to the oil layer. Compared with traditional chemical sand control, the production capacity recovery rate is increased by 20%-30%.

[0016] The resin microemulsion described in this application has droplet sizes in the micrometer to nanometer range, which matches the formation pore structure and allows for rapid and uniform distribution within underground pores. This avoids variations in sand control effectiveness caused by uneven dispersion, ensuring stable performance in the sand control area. The proportions of microemulsion components and injection parameters can be adjusted according to the physical properties, porosity, and particle size characteristics of different formations, effectively suppressing easily migrating particles and solving sand production problems in various formations.

[0017] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0018] Figure 1 The present invention provides an overall structural diagram of an integrated resin microemulsion dispersion system sand-proof device. Detailed Implementation

[0019] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Please see Figure 1 This invention provides an integrated resin microemulsion dispersion system sand-proof device, including a stirrer 1, an explosion-proof stirring motor 2 at the top of the stirrer 1, a high-pressure plunger pump 5 on the left side of the stirrer 1, a pipe at the bottom left of the stirrer 1 connecting one end of a centrifugal pump 3, a pipe at the top of the centrifugal pump 3 connecting one end of a Venturi jet 4, and the other end of the Venturi jet 4 connected to the stirrer 1 and the liquid outlet respectively via a three-way pipe. A water inlet is connected to the pipe at the top right of the stirrer 1. The explosion-proof stirring motor 2, the high-pressure plunger pump 5, and the centrifugal pump 3 are all electrically connected to a temperature control system 6. The stirring speed of the stirrer is adjustable from 0 to 1500 r / min with a speed control accuracy of ±5 r / min. The temperature control system has a temperature control range of 0 to 100℃ with an accuracy of ±1℃. Example 1

[0021] An oil and gas well with a completion depth of 2310m and a target well section of 2010-2020m has an oil layer porosity of 32% and consists of loose sandstone. It produces 5.6 kg of sand per day and requires sand control operations. The casing inner diameter is 124.30 mm, the working tubing inner diameter is 62 mm, the outer diameter is 73.02 mm, and the sand control radius is 1.5 m.

[0022] (1) Material preparation: 3380 kg of bisphenol A type epoxy resin (epoxy value 0.5 eq / 100g, degree of polymerization n=4); 230 kg of surfactant A and 115 kg of surfactant B; 130 kg of additive M; 780 kg of curing agent; 150 kg of fatty alcohol polyoxyethylene ether AEO-9; 593 kg of petroleum sulfonate; 22160 kg of pure water (conductivity 35 μS / cm).

[0023] (2) Synthesis of auxiliary agent E: 230 kg of surfactant A was added to the reactor, and 115 kg of surfactant B was slowly added at 400 r / min with a stirrer. The addition was completed in 10 min, and stirring was continued for 30 min.

[0024] (3) Mixing resin and additive E: Add 1126.7 kg of epoxy resin into the reactor, add additive E at 250 r / min with a stirrer, add it over 15 min, and stir for 15 min.

[0025] (4) Emulsion preparation: The reactor was stirred at 250 r / min, and the temperature was increased to 45℃ at 1.2℃ / min. The mixture was stirred at a constant temperature for 10 min. Pure water was slowly added at a rate of 10 L / min. When about 310 kg of pure water was added, the system was reversed. The remaining 7076.7 kg of pure water was added dropwise. After the addition was completed, the stirring speed was increased to 450 r / min and stirred for 50 min to ensure that the particle size distribution (PDI) was <0.18.

[0026] (5) Add other additives: After emulsification, cool to 30°C, add curing agent and reinforcing agent while stirring, and continue stirring for 30 minutes to complete the preparation of 8670 kg of resin emulsion. Repeat the above steps to complete the preparation of a total of 26010 kg of resin emulsion.

[0027] (6) Well washing operation: Connect the well washing process, and use the well washing pump to wash the well for 1.5 hours at a flow rate of 2.5 m³ / h. Check the turbidity of the well washing fluid every 15 minutes. If it is below 20 NTU, it is qualified and replaced with replacement fluid.

[0028] (7) Pretreatment fluid injection: The high-pressure plunger pump injects the pretreatment fluid at a speed of 0.15 m³ / min, with a pressure of 8.2-9.2 MPa (the surface fracture pressure of the oil layer is 10.2 MPa, and the injection friction is 0.2 MPa). After injection, the wellhead valve is closed and the well is left to stand for 1 hour.

[0029] (8) Resin microemulsion injection: Inject using a high-pressure plunger pump with a maximum working pressure of 80MPa and a flow rate adjustment accuracy of ±0.3%, at a speed of 0.1-0.3m³ / min and a pressure of 8.2-9.2MPa. Monitor the pressure and flow rate in real time to ensure that the pressure fluctuation is within ±5% of the set pressure.

[0030] (9) Well shut-in solidification: Close the wellhead valve and let it stand for 48 hours to allow the reaction to continue, keeping the oil layer temperature at the original temperature ±3℃.

[0031] (10) Fluid production: Control the bottom hole pressure difference to ≤2MPa for 1-5 days after well opening, and control it to ≤4.5MPa after 5 days. Sampling and analysis were conducted for 7 consecutive days. The highest particle content was 228g, the daily fluid production was 7.8 tons, the sand content was 0.0029%, and the sand control was qualified.

[0032] Example 2 An oil and gas well with a completion depth of 1980m, a target gas section of 1890-1895m, an oil layer porosity of 25%, and a sand production of 3-8kg / day requires sand control operations. The casing inner diameter is 124.30mm, the working tubing inner diameter is 62mm and the outer diameter is 73.02mm, and the sand control radius is 1.5m.

[0033] (1) Material preparation: 1320 kg of bisphenol A type epoxy resin (epoxy value 0.5 eq / 100g, degree of polymerization n=4); 88 kg of surfactant A and 44 kg of surfactant B; 50.8 kg of additive M; 304.8 kg of curing agent; 144 kg of fatty alcohol polyoxyethylene ether AEO-9; 271.7 kg of petroleum sulfonate; 8660 kg of pure water (conductivity 35 μS / cm).

[0034] (2) Synthesis of auxiliary agent E: 88 kg of surfactant A was added to the reactor, and 44 kg of surfactant B was added at 400 r / min with a stirrer. The addition was completed in 10 min, and stirring was continued for 30 min.

[0035] (3) Mixing resin and additive E: Add 1320 kg of epoxy resin into the reactor, add additive E at 250 r / min with a stirrer, add it over 15 min, and stir for 15 min.

[0036] (4) Emulsion preparation: The reactor was stirred at 250 r / min, and the temperature was increased to 45℃ at 1.2℃ / min. The mixture was stirred at a constant temperature for 10 min. Pure water was slowly added at a rate of 10 L / min. When about 330 kg of pure water was added, the system was reversed. The remaining 8330.0 kg of pure water was added dropwise. After the addition was completed, the stirring speed was increased to 450 r / min and stirred for 50 min to ensure that the particle size distribution (PDI) was <0.18.

[0037] (5) Add other additives: After emulsification, cool down to 30°C, add curing agent and reinforcing agent while stirring, and continue stirring for 30 minutes to complete the preparation of 10160kg resin emulsion.

[0038] (6) Well washing operation: The well washing pump washes the well for 1.5 hours at a flow rate of 2.5 m³ / h. The turbidity of the well washing fluid is checked every 15 minutes. If it is below 20 NTU, it is qualified and is replaced with displacement fluid.

[0039] (7) Pretreatment fluid injection: The high-pressure plunger pump injects the pretreatment fluid at a speed of 0.12 m³ / min, with a pressure of 9.0-10.2 MPa (the surface fracture pressure of the oil layer is 11.3 MPa, and the injection friction is 0.1 MPa). After injection, the wellhead valve is closed and the well is left to stand for 1 hour.

[0040] (8) Resin microemulsion injection: Inject using a high-pressure plunger pump with a maximum working pressure of 80MPa and a flow rate adjustment accuracy of ±0.3%, at a speed of 0.1-0.3m³ / min and a pressure of 9.0-10.2MPa. Monitor the pressure and flow rate in real time to ensure that the pressure fluctuation is within ±5% of the set pressure.

[0041] (9) Well shut-in solidification: Close the wellhead valve and let it stand for 48 hours to allow the reaction to continue, keeping the oil layer temperature at the original temperature ±3℃.

[0042] (10) Fluid production: Control the bottom hole pressure differential to ≤2.5MPa for 1-5 days after well opening, take samples for analysis for 3 consecutive days, the highest particle content is 100g, the daily fluid production is 3.8 tons, the sand content is 0.0026%, and the sand control is qualified. The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0043] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for sand control using an integrated resin microemulsion dispersion system, characterized in that, Includes the following steps: S1. Preparation of resin microemulsion: Select epoxy resin, add additive E and stir at a speed of 200-350 r / min for 15-20 min. Add pure water in stages and gradually increase the stirring speed to 1000 r / min. Then add curing agent and reinforcing agent and continue stirring to form a stable resin microemulsion with a particle size of 150-350 nm and a solid content of 12%-15%. S2. Well washing operation: Clean the wellbore with a well washing fluid containing 0.5% (by mass) fatty alcohol polyoxyethylene ether AEO-9. The fatty alcohol polyoxyethylene ether AEO-9 has the structural formula RO-(CH2CH2O)9H, where R represents C. 15 ~C 17 The fatty alcohol groups are removed, the flow rate is controlled at 3.5-5.5 m³ / h, and then a portable turbidity analyzer with a range of 0-1000 NTU and an accuracy of 2% FS is used to detect the turbidity of the well washing fluid. The well washing is considered qualified when the turbidity of the well washing fluid is lower than 20 NTU. S3. Formation pretreatment: Inject a pretreatment solution containing 1% petroleum sulfonate by mass, the amount of which is twice the volume of the resin microemulsion, and the flow rate is 0.1-0.5 m³ / min. The liquid level at the end of the pretreatment solution section is injected to the top boundary of the sand control oil layer section. S4. Resin microemulsion injection: Injected using a high-pressure plunger pump at a pressure of 80-90% of the rock fracturing pressure in the oil reservoir, with an injection flow rate of 0.1-0.5 m³ / min and an injection volume V. f The calculation formula is determined based on the oil layer thickness and porosity. ； Where ∅ is porosity, H is oil layer thickness, and r is sand control radius. The tail end of the sand control liquid is injected to the top boundary of the sand control oil layer section. S5. Well shut-in solidification: Close the wellhead valve for 12-72 hours and maintain the oil layer temperature at the original temperature ±3℃. S6. Fluid production: Start production for 1-5 days, controlling the bottom pressure differential to ≤3MPa. After 5 days, increase the fluid production rate and control the bottom pressure differential to ≤8MPa until the discharged fluid has no obvious solid particles and the flow rate is stable.

2. A method for sand control using an integrated resin microemulsion dispersion system, characterized in that, The system includes a microemulsion preparation device, a well-washing device, a high-pressure injection device, and a monitoring and control device. The microemulsion preparation device includes a stirrer and a temperature control system. The stirring speed of the stirrer is adjustable from 0 to 1500 r / min with a speed control accuracy of ±5 r / min. The temperature control system has a temperature control range of 0 to 100℃ with an accuracy of ±1℃. The high-pressure injection device is a high-pressure plunger pump. The monitoring and control device integrates a pressure sensor, a flow sensor, and a data processing unit.

3. The sand-prevention method for an integrated resin microemulsion dispersion system according to claim 1, characterized in that, The epoxy resin is of type bisphenol A, with the general molecular formula C0. 11 H 12 O3(C3H6O) n， Where n is the degree of polymerization, ranging from 2 to 5, and the purity is ≥97%; the auxiliary agent E is a compound of two surfactants A and B in a certain mass ratio, and the general molecular formula of surfactant A is C9H. 19 C6H4(OCH2CH2) 10 The molecular structure of surfactant OH,B is C 12 H 25 SO4Na, A and B in a mass ratio of 2:1, and the amount of additive E added is 8%-12% of the epoxy resin mass; after adding pure water, the stirring speed is controlled by stepwise increase, with an increase of 100r / 5min, and the speed is gradually increased to 1000r / min in 5-7 times, with a total stirring time ≥90min.

4. The sand-prevention method for an integrated resin microemulsion dispersion system according to claim 1, characterized in that, The purity requirement for the pure water is: conductivity 30-50 μS / cm, and mass fraction of 82.5-85.9% of the total amount of resin microemulsion.

5. The sand-prevention method for an integrated resin microemulsion dispersion system according to claim 1, characterized in that, After the epoxy resin microemulsion dispersion system was prepared, the particle size distribution of the microemulsion was detected using a portable laser particle size analyzer with a measurement range of 0-1000 μm and an accuracy of 1%FS.

6. The sand-prevention method for an integrated resin microemulsion dispersion system according to claim 1, characterized in that, The curing agent is a modified amine with a molecular structure containing ≥3 amine active groups; the amount of well-washing fluid used is twice the wellbore volume.

7. The sand-prevention method for an integrated resin microemulsion dispersion system according to claim 1, characterized in that, The high-pressure plunger pump has a maximum working pressure of ≥70MPa, a flow rate adjustment accuracy of ±0.3%FS, and an injection pressure fluctuation of ≤±5% of the set pressure.

8. The sand-prevention method for an integrated resin microemulsion dispersion system according to claim 1, characterized in that, The displacement fluid is active water containing 0.5% petroleum sulfonate by mass, and the amount used in a single application is to inject the displacement fluid from the tail end of the liquid surface to the top boundary of the sand control oil layer.

9. The sand-prevention method for an integrated resin microemulsion dispersion system according to claim 1, characterized in that, In the process of draining the liquid, the draining is considered complete when the mass ratio of solid particles in the drained liquid is less than 0.5%.

10. An apparatus for sand prevention in an integrated resin microemulsion dispersion system according to claims 1-9, comprising a stirrer, an explosion-proof stirring motor at the top of the stirrer, a high-pressure plunger pump on the left side of the stirrer, a pipe at the bottom left of the stirrer connecting one end of a centrifugal pump, a pipe at the top of the centrifugal pump connecting one end of a Venturi jet injector, the other end of the Venturi jet injector being connected to the stirrer and the liquid outlet respectively via a T-connector, a pipe at the top right of the stirrer connecting to a water inlet, the explosion-proof stirring motor, the high-pressure plunger pump, and the centrifugal pump being electrically connected to a temperature control system, the stirring speed of the stirrer being adjustable from 0 to 1500 r / min with a speed control accuracy of ±5 r / min, and the temperature control system having a temperature control range of 0 to 100℃ with an accuracy of ±1℃.

Images