Heavy oil reservoir sand control agent, sand control treatment fluid system and sand control method

Abstract

The invention provides a heavy oil reservoir sand control agent, a sand control treatment fluid system and a sand control method, and belongs to the technical field of oil extraction. The sand control agent for the heavy oil reservoir comprises proppant particles, and an inner-layer epoxy resin film and an outer-layer resin film which are sequentially coated on the surfaces of the proppant particles, the outer layer resin film is prepared from a reaction product of polyisocyanate, bisphenol A type polyether glycol, dimer acid and 4, 4-diphenylmethane diamine. The heavy oil reservoir sand control agent has a good water control effect and high compressive strength.

Description

Technical Field

[0001] The invention belongs to the technical field of oil production, and in particular relates to a heavy oil reservoir sand control agent, a sand control treatment fluid system and a sand control method. Background Art

[0002] During the exploitation of sandstone oil layers, the loose sandstone oil layer structure is loose and the cementation performance is poor, resulting in serious sand production. my country's loose sandstone reservoirs are widely distributed, with large reserves and an important production output. However, sand production is extremely harmful. For example, sand buries oil, gas and water layers, resulting in reduced production. Sand particles rub downhole equipment, resulting in shortened life and increased production costs. Large amounts of sand production may cause the oil well to be scrapped. Therefore, sand prevention of sand-producing wells is the primary measure to ensure the normal production of oil fields.

[0003] With the continuous deepening of oilfield development, the reservoir has entered a period of high or ultra-high water content, and the sand production of oil wells has become increasingly complex and diversified, seriously affecting the production capacity of oil wells. At present, the main sand control measures include mechanical sand control, chemical sand control, coking sand control, etc. Mechanical sand control methods include various screen sand control methods, which are simple but cannot prevent and control fine silt, mud and clay materials with smaller particle sizes. Chemical sand control mainly focuses on fracturing sand control, artificial well wall sand control, chemical sand consolidation, etc., which can be used for the prevention and control of fine silt, but the traditional chemical sand control agent has poor compressive strength performance and does not meet the water resistance standard, which cannot meet the needs of current oilfield development.

[0004] Therefore, in order to improve the sand control problem in the water-containing period of the reservoir and improve the sand control effect, it is necessary to develop a heavy oil reservoir sand control agent, a sand control treatment fluid system and a sand control method. Summary of the invention

[0005] Based on the deficiencies of the prior art, the first object of the present invention is to provide a heavy oil reservoir sand control agent, which can not only meet the function of chemical sand control, but also has a water control function and high compressive strength.

[0006] The second object of the present invention is to provide a sand control treatment liquid system, which forms a bonding coating on the surface of fine siltstone and clay particles to cement and consolidate sand.

[0007] The third object of the present invention is to provide a sand control method to achieve sand control in heavy oil reservoirs.

[0008] To achieve the above purpose, the technical solution adopted by the present invention is as follows: In one aspect, the present invention provides a heavy oil reservoir sand control agent, comprising proppant particles, and an inner epoxy resin film and an outer resin film sequentially coated on the surface of the proppant particles; wherein: The outer resin film comprises a reaction product of polyisocyanate, bisphenol A type polyether diol, dimer acid and 4,4-diphenylmethanediamine.

[0009] Furthermore, the epoxy resin in the inner epoxy resin film is selected from bisphenol A epoxy resin with an epoxy equivalent of 200 to 500 g / eg.

[0010] Furthermore, the polyisocyanate is selected from at least one of aliphatic polyisocyanate and aromatic polyisocyanate.

[0011] Optionally, the polyisocyanate includes but is not limited to at least one of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, 2,4,6-trimethylphenyl isocyanate, and 4,4'-methylenebis(2,6-diethylphenyl isocyanate).

[0012] Furthermore, the bisphenol A type polyether diol is a bisphenol A type polyether diol with a hydroxyl value of 250 to 300, preferably a bisphenol A type polyether diol with a hydroxyl value of 300.

[0013] Furthermore, in the outer resin film, the mass ratio of polyisocyanate, bisphenol A type polyether diol, dimer acid, and 4,4-diphenylmethanediamine is 100:(80-95):(1-2):(0.5-2).

[0014] Preferably, in the outer resin film, the mass ratio of polyisocyanate, bisphenol A type polyether diol, dimer acid and 4,4-diphenylmethanediamine is 100:85:1.5:2.

[0015] Furthermore, the proppant particles are selected from at least one of quartz sand, ceramsite sand, mica powder, diatomaceous earth, bauxite, glass beads, fly ash, calcium oxide, and zinc oxide.

[0016] Furthermore, the proppant particles are selected from a mixture of particles with a particle size of 30-40 mesh and 60-70 mesh, and the mixing mass ratio of the particles with a particle size of 30-40 mesh and 60-70 mesh is (90-95):(5-10).

[0017] Furthermore, in the heavy oil reservoir sand control agent, the mass ratio of the proppant particles, the inner epoxy resin film and the outer resin film is 100:(1.5-3):(0.5-2).

[0018] Preferably, the mass ratio of the proppant particles, the inner epoxy resin film and the outer resin film is 100:2:1.2.

[0019] In a further embodiment, the outer resin film of the heavy oil reservoir sand control agent further comprises 3,3',5,5'-tetramethylbiphenyl diglycidyl ether, and the addition amount of the 3,3',5,5'-tetramethylbiphenyl diglycidyl ether is 2% to 4% of the mass of the polyisocyanate.

[0020] The method for preparing the above-mentioned heavy oil reservoir sand control agent comprises the following steps: (1) 40% to 50% of the total amount of polyisocyanate and bisphenol A polyether diol are mixed, reacted at 80 to 90°C for 2 to 3 hours, and then the remaining polyisocyanate, dimer acid, 4,4-diphenylmethanediamine, and a catalyst are added, the temperature is lowered to 25 to 35°C, and the reaction is continued for 0.5 to 1 hour to obtain a polyurethane mixed solution; (2) Mix epoxy resin, proppant particles and water, heat to 150-160° C., react for 90-120 seconds, dry, sieve, and then add to the polyurethane mixed solution obtained in step (1), mix for 120-180 seconds, dry, crush, and sieve to obtain a heavy oil reservoir sand control agent.

[0021] Furthermore, in step (1), after cooling to 25-35° C., 3,3',5,5'-tetramethylbiphenol diglycidyl ether is added.

[0022] Furthermore, the catalyst is an organic tin catalyst, and the added amount of the catalyst is 0.02% to 0.1% of the mass of the polyisocyanate.

[0023] Optionally, the catalyst includes but is not limited to at least one of dibutyltin dilaurate, stannous octoate, dibutyltin didodecylsulfide, and alkyltin dithiolate.

[0024] On the other hand, the present invention provides a sand control treatment fluid system, comprising a pre-fluid, a sand-carrying fluid, and a displacement fluid; wherein the sand-carrying fluid contains 5% to 8% by weight of the above-mentioned heavy oil reservoir sand control agent.

[0025] Furthermore, the mass ratio of the pre-fluid, the sand-carrying fluid and the displacement fluid is (20-25): (60-65): (10-20).

[0026] Furthermore, the sand-carrying fluid comprises the following components by mass percentage: 1% to 5% of a thickener, 0.5% to 2.5% of an anti-swelling agent, 0.2% to 0.3% of a drainage aid, 5% to 8% of a heavy oil reservoir sand control agent, and the remainder is water.

[0027] Optionally, the thickener is guar gum or hydroxypropyl guar gum.

[0028] Optionally, the drainage aid is a sulfonate type anionic surfactant, preferably sodium dodecyl sulfonate / or sodium dodecylbenzene sulfonate.

[0029] Optionally, the anti-swelling agent is a clay anti-swelling agent.

[0030] In a further embodiment, the sand-carrying fluid further comprises 0.2% to 0.5% of polyglycerol-10 stearate and polyglycerol-10 pentamethylenetetradecanoate; the mixing mass ratio of polyglycerol-10 stearate to polyglycerol-10 pentamethylenetetradecanoate is 1:2 to 3.

[0031] In another aspect, the above-mentioned heavy oil reservoir sand control agent or sand control treatment liquid system is used in sand control treatment of heavy oil reservoirs.

[0032] In yet another aspect, a sand control treatment method comprises performing sand control treatment using the aforementioned heavy oil reservoir sand control agent or sand control treatment liquid system.

[0033] The above-mentioned sand control treatment method comprises the following steps: S1. Pull out the original production pipe string; S2, lower the sand flushing column; S3, sand flushing, well cleaning, well washing and pipe scraping; S4, lowering the sand control column; S5, setting the seal, opening the filling tube, injecting the aforementioned pre-fluid, sand-carrying fluid, and displacement fluid in sequence, and shutting in the well for reaction; S6. Let go and complete the well.

[0034] Furthermore, in step S3, the sand flushing fluid used for sand flushing is clean water; and the well flushing fluid used for well flushing is clean water.

[0035] Furthermore, in step S5, the reaction time of the shut-in reaction is 24 to 48 hours.

[0036] Furthermore, in step S5, the total injection amount of the pre-fluid, sand control agent and sand-carrying fluid is 300-500 L / min.

[0037] Compared with the prior art, the present invention has the following beneficial effects: 1. The heavy oil reservoir sand control agent provided by the present invention not only meets the function of chemical sand control, but also has good water control effect and high compressive strength.

[0038] 2. In the process of preparing the heavy oil reservoir sand control agent of the present invention, dimer acid and 4,4-diphenylmethane diamine are added to the outer resin film. The long chain and branched structure of the dimer acid make the outer resin film have good hydrolysis resistance, which can achieve that when the proppant enters the underground reservoir and is exposed to water, it can maintain high strength and durability; the introduction of 4,4-diphenylmethane diamine increases the bonding between the polyurethane and the proppant particles, so that the interface adhesion and durability are enhanced; in addition, the simultaneous addition of dimer acid and 4,4-diphenylmethane diamine also has a certain synergistic effect, which can further improve the coating strength, improve the water control ability, and improve the high temperature resistance.

[0039] 3. The sand control treatment fluid system provided by the present invention adds a certain amount of polyglycerol-10 stearate and polyglycerol-10 pentastearate to the sand-carrying fluid, which can reduce the viscosity of heavy oil, improve the development effect of heavy oil reservoirs, and improve the storage stability of the sand-carrying fluid while ensuring good sand carrying capacity.

[0040] 4. The sand control method provided by the present invention has simple construction steps and realizes the production demand for sand control of fine silt sand oil layers. DETAILED DESCRIPTION

[0041] The following non-limiting examples can enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way. The following content is only an exemplary description of the scope of the present invention, and those skilled in the art can make various changes and modifications to the invention of the present invention based on the disclosed content, and they should also fall within the scope of the present invention.

[0042] The pre-fluid, sand-carrying fluid and displacement fluid of the present invention are all pre-fluid, sand-carrying fluid and displacement fluid conventionally used for sand control in the art. Those skilled in the art can select and regulate the type and amount of the pre-fluid, sand-carrying fluid and displacement fluid according to the specific conditions of the heavy oil reservoir.

[0043] For example, the pre-pad liquid can be selected from the pre-pad liquid containing the following components, including 8% to 10% hydrochloric acid, 0.5% to 2% calcium chloride, 0.5% to 1.5% non-ionic surfactant, 0.5% to 1.5% cationic surfactant, and the balance is water. 0.5% to 2% of sand control agent and 0.2% to 0.5% anti-swelling agent can also be added to the pre-pad liquid. The anti-swelling agent and sand control agent are conventional sand control agents in the art, and the sand control agent can also be the sand control agent provided by the present invention. In the following specific embodiments, the pre-pad liquid contains, by mass percentage: 10% hydrochloric acid, 1% calcium chloride, 1% non-ionic surfactant, 1% cationic surfactant, 0.2% quaternary ammonium salt-II type clay anti-swelling agent, and the balance is water.

[0044] For example, the displacement fluid can be selected from the displacement fluid containing the following components, including: 0.5% to 1.5% non-ionic surfactant, 1% to 2% ethylene glycol monoethyl ether, 1% to 2% ammonium chloride, and the balance is water. 0.5% to 2% of sand control agent and 0.2% to 0.5% of anti-swelling agent can also be added to the displacement fluid. The anti-swelling agent and sand control agent are conventional sand control agents in the field, and the sand control agent can also be the sand control agent provided by the present invention. In the following specific embodiments, the displacement fluid contains, by mass percentage, 15% polyol non-ionic surfactant, 1% ethylene glycol monoethyl ether, 1.4% ammonium chloride, 0.2% quaternary ammonium salt-II type clay anti-swelling agent, and the balance is water.

[0045] The present invention is further described below by way of specific examples. Unless otherwise specified, the various chemical reagents used in the examples of the present invention are obtained through conventional commercial channels.

[0046] Example 1 This embodiment provides a heavy oil reservoir sand control agent, which is prepared by the following method: (1) 50 g of toluene diisocyanate and 80 g of bisphenol A type polyether diol (hydroxyl value is 250) were mixed and reacted at 80°C for 3 h; then 50 g of toluene diisocyanate, 1 g of dimer acid, 0.5 g of 4,4-diphenylmethanediamine and 0.1 g of dibutyltin dilaurate were added, the temperature was lowered to 35°C, and the reaction was continued for 0.5 h to obtain a polyurethane resin mixture; (2) Epoxy resin E-44, proppant (a mixture of quartz sand with a particle size of 30 mesh and 70 mesh, with a mixing mass ratio of 90:10) and water in a mass ratio of 1.5:100:5 were mixed at 160°C for 90 seconds, dried, sieved, and then added to a polyurethane resin mixture with a mass ratio of 0.5% of the proppant mass, mixed for 120 seconds, dried, crushed, and sieved to obtain a heavy oil reservoir sand control agent.

[0047] This embodiment also provides a sand control treatment fluid system, comprising a pre-fluid, a sand carrying fluid, and a displacement fluid in a mass ratio of 25:65:10; The sand-carrying fluid comprises the following components in terms of mass percentage: 1% hydroxypropyl guar gum, 0.5% quaternary ammonium salt-II type clay anti-swelling agent, 0.3% sodium dodecyl sulfate, 5% of the above-mentioned heavy oil reservoir sand control agent, and the balance is water.

[0048] This embodiment also provides a sand control method, comprising the following steps: S1. Pull out the original production pipe string; S2, lower the sand flushing column; S3, sand flushing, well cleaning, well washing and pipe scraping; S4, lowering the sand control column; S5, seal the well, open the filling tube, and inject the pre-fluid, sand-carrying fluid, and displacement fluid in sequence at a total injection rate of 300L / min, and shut in the well for 48h; S6. Let go and complete the well.

[0049] Example 2 This embodiment provides a heavy oil reservoir sand control agent, which is prepared by the following method: (1) 50 g of 2,4,6-trimethylphenyl isocyanate and 85 g of bisphenol A polyether diol (hydroxyl value of 300) were mixed and reacted at 90°C for 2 h, then 50 g of 2,4,6-trimethylphenyl isocyanate, 1.5 g of dimer acid, 2 g of 4,4-diphenylmethanediamine, and 0.1 g of dibutyltin dilaurate were added, the temperature was lowered to 25°C, and the reaction was continued for 0.5 h to obtain a polyurethane resin mixed solution; (2) Epoxy resin E-44, proppant (a mixture of quartz sand with a particle size of 30 mesh and 60 mesh, with a mixing mass ratio of 90:10) and water in a mass ratio of 2:100:5 were mixed at 160°C for 90 seconds, dried, sieved, and then added to a polyurethane resin mixture containing 1.2% of the proppant mass, mixed for 120 seconds, dried, crushed, and sieved to obtain a heavy oil reservoir sand control agent.

[0050] This embodiment also provides a sand control treatment fluid system, comprising a pre-fluid in a mass ratio of 20:60:20, a mixed solution of the above-mentioned heavy oil reservoir sand control agent and a sand-carrying fluid, and a displacement fluid; The sand-carrying fluid comprises the following components in terms of mass percentage: 5% hydroxypropyl guar gum, 2.5% quaternary ammonium salt-II type clay anti-swelling agent, 0.2% sodium dodecyl sulfate, 8% heavy oil reservoir sand control agent, and the balance is water.

[0051] This embodiment also provides a sand control method, comprising the following steps: S1. Pull out the original production pipe string; S2, lower the sand flushing column; S3, sand flushing, well cleaning, well washing and pipe scraping; S4, lowering the sand control column; S5, seal the well, open the filling tube, and inject the pre-fluid, sand-carrying fluid, and displacement fluid in sequence at a total injection rate of 300L / min, and shut in the well for 48h; S6. Let go and complete the well.

[0052] Example 3 This embodiment provides a heavy oil reservoir sand control agent, which is prepared by the following method: (1) 50 g of toluene diisocyanate and 95 g of bisphenol A type polyether diol (hydroxyl value of 300) were mixed and reacted at 80°C for 3 h, then 50 g of toluene diisocyanate, 2 g of dimer acid, 2 g of 4,4-diphenylmethanediamine, and 0.1 g of dibutyltin dilaurate were added, the temperature was lowered to 35°C, and the reaction was continued for 0.5 h to obtain a polyurethane resin mixture; (2) Epoxy resin E-44, proppant (a mixture of quartz sand with a particle size of 40 mesh and 70 mesh, with a mixing mass ratio of 95:5) and water in a mass ratio of 3:100:5 were mixed at 160°C for 90 seconds, dried, sieved, and then added to a polyurethane resin mixture with a mass ratio of 2% of the proppant, mixed for 120 seconds, dried, crushed, and sieved to obtain a heavy oil reservoir sand control agent.

[0053] This embodiment also provides a sand control treatment fluid system, comprising a pre-fluid in a mass ratio of 20:60:20, a mixed solution consisting of the above-mentioned sand control agent and sand-carrying fluid, and a displacement fluid; The sand-carrying fluid comprises the following components in terms of mass percentage: 5% hydroxypropyl guar gum, 2.5% quaternary ammonium salt-II type clay anti-swelling agent, 0.2% sodium dodecyl sulfate, 8% heavy oil reservoir sand control agent, and the balance is water.

[0054] This embodiment also provides a sand control method, comprising the following steps: S1. Pull out the original production pipe string; S2, lower the sand flushing column; S3, sand flushing, well cleaning, well washing and pipe scraping; S4, lowering the sand control column; S5, seal the well, open the filling tube, and inject the pre-fluid, sand-carrying fluid, and displacement fluid in sequence at a total injection rate of 300L / min, and shut in the well for 48h; S6. Let go and complete the well.

[0055] Example 4 The difference between this embodiment and embodiment 2 is that, in the process of preparing the polyurethane resin mixed solution, the amount of dimer acid used is 0.5 g and the amount of 4,4-diphenylmethanediamine used is 0.3 g, that is, the mass ratio of polyisocyanate, bisphenol A type polyether diol (hydroxyl value is 300), dimer acid, and 4,4-diphenylmethanediamine is 100:85:0.5:0.3.

[0056] Example 5 The difference between this embodiment and embodiment 2 is that, in the process of preparing the polyurethane resin mixed solution, the amount of dimer acid used is 3 g, and the amount of 4,4-diphenylmethanediamine used is 2.5 g, that is, the mass ratio of polyisocyanate, bisphenol A type polyether diol (hydroxyl value is 300), dimer acid, and 4,4-diphenylmethanediamine is 100:85:3:2.5.

[0057] Example 6 The difference between this embodiment and embodiment 2 is that the steps of preparing the polyurethane resin mixed solution are: Mix 50g toluene diisocyanate and 95g bisphenol A type polyether diol (hydroxyl value is 300), react at 80°C for 3h, then add 50g toluene diisocyanate, 2g dimer acid, 2g 4,4-diphenylmethanediamine, add 0.1g dibutyltin dilaurate, cool to 35°C, add 4g 3,3',5,5'-tetramethylbiphenyl diglycidyl ether, continue to react for 0.5h, and obtain a polyurethane resin mixture.

[0058] Example 7 The difference between this embodiment and embodiment 6 is that 3,3',5,5'-tetramethylbiphenol diglycidyl ether is replaced by an equal amount of bisphenol A diglycidyl ether.

[0059] Example 8 The difference between this embodiment and embodiment 2 is that the sand-carrying fluid comprises the following components in terms of mass percentage: 5% hydroxypropyl guar gum, 2.5% quaternary ammonium salt-II type clay anti-swelling agent, 0.2% sodium dodecyl sulfate, 8% sand control agent, 0.5% polyglycerol-10 stearate and polyglycerol-10 pentastearate, and the balance is water; wherein the mass ratio of polyglycerol-10 stearate to polyglycerol-10 pentastearate is 1:2.

[0060] Example 9 The difference between this embodiment and embodiment 8 is that the sand-carrying liquid comprises the following components in terms of mass percentage: 5% hydroxypropyl guar gum, 2.5% quaternary ammonium salt-II type clay anti-swelling agent, 0.2% sodium dodecyl sulfate, 8% sand control agent, 0.5% polyglycerol-10 stearate, and the balance is water.

[0061] Example 10 The difference between this embodiment and embodiment 8 is that the sand-carrying liquid comprises the following components in terms of mass percentage: 5% hydroxypropyl guar gum, 2.5% quaternary ammonium salt-II type clay anti-swelling agent, 0.2% sodium dodecyl sulfate, 8% sand control agent, 0.5% polyglycerol-10 pentastearate, and the balance is water.

[0062] Embodiment 11 The difference between this embodiment and embodiment 8 is that the polyglycerol-10 stearate in the sand-carrying fluid is replaced by an equal amount of polyglycerol-10 laurate.

[0063] Comparative Example 1 The difference between this comparative example and Example 2 is that dimer acid is not added during the preparation of the polyurethane resin mixed solution.

[0064] Comparative Example 2 The difference between this comparative example and Example 2 is that 4,4-diphenylmethanediamine is not added during the preparation of the polyurethane resin mixed solution.

[0065] Comparative Example 3 The difference between this comparative example and Example 2 is that dimer acid and 4,4-diphenylmethanediamine are not added during the preparation of the polyurethane resin mixed solution.

[0066] Comparative Example 4 The difference between this comparative example and Example 2 is that the hydroxyl value of the bisphenol A type polyether diol in the process of preparing the polyurethane resin mixed solution is 200.

[0067] Test Example 1 Performance test of sand control agent in heavy oil reservoir The sand control agents in the above Examples 1 to 7 and Comparative Examples 1 to 4 were mixed with a solidifying liquid at a mass ratio of 20:1, wherein the solidifying liquid was a 2-methylimidazole solution with a mass concentration of 5%, and then placed in a water bath at 40° C. for curing, and the consolidated parts were subjected to the following tests: 1. Compressive strength test: Use a compression machine to measure the compressive strength after curing for 12h-72h; 2. Permeability: Take two consolidated pieces after curing for 48 hours and put them into the core permeability tester. One piece is soaked and rinsed with water for 30 days, and the other piece is soaked and rinsed with kerosene for 30 days. The oil phase permeability and water phase permeability of the two consolidated pieces are measured. 3. Temperature resistance: The compressive strength of the consolidated parts at 100-300°C after 48 hours of curing is tested to evaluate its high temperature resistance.

[0068] The results are shown in Tables 1 and 2 below.

[0069] Table 1

[0070] Table 2

[0071] As shown in the table, compared with comparative example 3, the compressive strength of comparative examples 1 and 2 is improved. It can be seen that in the preparation process of the polyurethane resin mixed solution of the outer resin film, adding dimer acid or 4,4-diphenylmethane diamine can help improve the strength of the sand control agent; and compared with comparative examples 1 to 3, the compressive strength of the sand control agent prepared by Examples 1 to 5 is significantly higher than that of the comparative examples, indicating that in the preparation process of the polyurethane resin mixed solution, adding dimer acid and 4,4-diphenylmethane diamine at the same time can further improve the strength of the sand control agent. The compressive strength of Example 6 is higher than that of Example 2, and in Example 7, the glycidyl ether is replaced, and its compressive strength at 12h is equivalent to that of Example 6, but as the curing time increases, the compressive strength of Example 7 begins to be lower than that of Example 6, and is equivalent to that of Example 2. It can be seen that adding specific glycidyl ether in the preparation process of the polyurethane resin mixed solution can further improve the strength of the sand control agent.

[0072] It can also be seen that compared with comparative examples 1 to 3, the oil phase permeability of the sand control agent of the present invention is still greater than 40 μm when kerosene is continuously passed for 30 days. 2 , water phase permeability is not more than 20μm 2 The water control effect is good. This shows that adding dimer acid and 4,4-diphenylmethanediamine to the polyurethane resin mixture is helpful to improve the water control ability of the sand control agent and make up for the defects of the prior art.

[0073] It can also be seen that the compressive strength of Comparative Examples 1 to 3 at high temperatures, especially at 200°C and 300°C, is significantly lower than that of Example 2, and the compressive strength of Examples 4 and 5 at high temperatures is also lower than that of Example 2. It can be seen that when dimer acid and 4,4-diphenylmethanediamine are introduced into the outer resin film at the same time, the two have a certain synergistic effect, which helps to improve the high temperature resistance of the sand control agent. The compressive strength of Example 6 at high temperature is higher than that of Example 2, while the compressive strength of Example 7 at high temperature is slightly lower than that of Example 2. It can be seen that the introduction of specific glycidyl ether into the outer resin film of the present invention helps to further improve the high temperature resistance.

[0074] Test Example 2 Sand carrying agent performance test 1. The following tests were performed on the sand-carrying fluids in Examples 2, 8 to 11, and Comparative Examples 1 to 3: Viscosity reduction effect: Referring to the petroleum industry standard SY / T 0520-2008 "Determination of Crude Oil Viscosity by Rotational Viscometer Balance Method", 100mL of crude oil was kept at a constant temperature of 50°C for 1h, and the viscosity of the heavy oil was measured using a NDJ-8S digital viscometer, which was recorded as η0; 2% of the sand-carrying liquid was added to the crude oil and stirred evenly. The crude oil had a viscosity of 2860mPa·s and was heated at a constant temperature of 50°C in a water bath for 2h. The viscosity was tested and recorded as η1. Finally, the viscosity reduction rate was calculated according to the formula ν=[(η0-η1) / η0]×100%.

[0075] 2. Use NDJ-8S digital viscometer to measure the viscosity of the sand-carrying fluid after long-term storage to evaluate its stability.

[0076] The measured results are shown in Table 3 below.

[0077] Table 3

[0078] As shown in the table, the viscosity reduction rate of the sand-carrying fluid for heavy oil in Example 2 is 88.2%. A certain amount of polyglycerol-10 stearate and polyglycerol-10 pentamethylenetetradecanoate are added to the sand-carrying fluid in Example 8, and its viscosity reduction rate is significantly increased, and the viscosity reduction effect is improved, while the viscosity reduction rates of Examples 9 to 11 are equivalent to that of Example 2, or even slightly decreased, and the viscosity reduction rates of Comparative Examples 1 to 3 are lower than those of Example 2. It can be seen that the invention adds specific polyglycerol-10 stearate and polyglycerol-10 pentamethylenetetradecanoate to the sand-carrying fluid, which has a certain synergistic effect with the proppant, and is helpful to improve the viscosity reduction effect of the sand-carrying fluid.

[0079] It can also be seen that the viscosity of the sand-carrying fluids of Examples 2 and 8 remains basically unchanged after being placed for 72 hours, and the stability is good; the viscosity of the sand-carrying fluids of Examples 9 to 11 decreases after being placed for 72 hours; the viscosity of the sand-carrying fluids of Comparative Examples 1 to 3 begins to decrease significantly after being placed for 12 hours or 24 hours. It can be seen that the specific polyglycerol-10 stearate and polyglycerol-10 pentastearate added to the sand-carrying fluid of the present invention have a certain synergistic effect with the proppant, which helps to improve the stability of the sand-carrying fluid.

[0080] Test Example 3 Implementation of typical well cases A sand producing area of ​​a water well in Shengli Oilfield has accumulated 12m of sand, with a sand particle size of 0.282mm, a crude oil viscosity of 680mPa•s at 50°C, a colloid asphaltene content of 28.5%, serious formation sand production, frequent pump jams, and a casing change at 1698.0m. After the sand control method described in Example 2 was used for construction, the occurrence of fine sand and mud blockage was significantly reduced. At present, the daily liquid production is 22.6m and the daily oil production is 3.4t.

[0081] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A heavy oil reservoir sand control agent, characterized in that: It comprises proppant particles, and an inner epoxy resin film and an outer resin film sequentially coated on the surface of the proppant particles; The outer resin film comprises a reaction product of polyisocyanate, bisphenol A type polyether diol, dimer acid and 4,4-diphenylmethanediamine; The mass ratio of the polyisocyanate, bisphenol A type polyether diol, dimer acid and 4,4-diphenylmethanediamine is 100:80-95:1-2:0.5-2.

2. The heavy oil reservoir sand control agent according to claim 1, characterized in that: In the outer layer resin film, the bisphenol A type polyether diol is a bisphenol A type polyether diol having a hydroxyl value of 250-300.

3. The heavy oil reservoir sand control agent according to claim 1 or 2, characterized in that: The mass ratio of the proppant particles, the inner epoxy resin film and the outer resin film is 100:1.5-3:0.5-2.

4. The method for preparing a heavy oil reservoir sand control agent according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) 40% to 50% of the total amount of polyisocyanate and bisphenol A polyether diol are mixed, reacted at 80 to 90°C for 2 to 3 hours, and then the remaining polyisocyanate, dimer acid, 4,4-diphenylmethanediamine, and a catalyst are added, the temperature is lowered to 25 to 35°C, and the reaction is continued for 0.5 to 1 hour to obtain a polyurethane mixed solution; (2) Mix epoxy resin, proppant particles and water, heat to 150-160° C., react for 90-120 seconds, dry, sieve, and then add to the polyurethane mixed solution obtained in step (1), mix for 120-180 seconds, dry, crush, and sieve to obtain a heavy oil reservoir sand control agent.

5. A sand control treatment liquid system, characterized in that: It comprises a pre-fluid, a sand-carrying fluid and a displacement fluid; wherein the sand-carrying fluid comprises the heavy oil reservoir sand control agent according to any one of claims 1 to 3.

6. The sand control treatment liquid system according to claim 5, characterized in that: The sand-carrying fluid comprises the following components in percentage by weight: 0.1% to 5% of a thickener, 0.5% to 2.5% of an anti-swelling agent, 0.2% to 0.3% of a drainage agent, 5% to 8% of the heavy oil reservoir sand control agent according to any one of claims 1 to 3 or the heavy oil reservoir sand control agent prepared by the preparation method according to claim 4, and the remainder is water.

7. The sand control treatment liquid system according to claim 6, characterized in that: The sand-carrying fluid also contains 0.2% to 0.5% of polyglycerol-10 stearate and polyglycerol-10 pentastearate, and the mass ratio of the polyglycerol-10 stearate to the polyglycerol-10 pentastearate is 1:2 to 3.

8. A sand control method, characterized in that: The method comprises performing sand control treatment by using the heavy oil reservoir sand control agent according to any one of claims 1 to 3 or the sand control treatment fluid system according to any one of claims 5 to 7.

9. The sand control method according to claim 8, characterized in that: The following steps are involved: S1. Pull out the original production pipe string; S2, lower the sand flushing column; S3, sand flushing, well cleaning, well washing and pipe scraping; S4, lowering the sand control column; S5, setting the seal, opening the filling tube, injecting the pre-fluid, the sand-carrying fluid described in any one of claims 5 to 7, and the displacement fluid in sequence, and shutting in the well for reaction; S6. Let go and complete the well.

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