Temperature-resistant and salt-resistant oily sludge deep plugging agent and preparation method thereof

Abstract

The invention provides a temperature-resistant and salt-resistant oil-containing sludge deep plugging agent and a preparation method thereof, and the temperature-resistant and salt-resistant oil-containing sludge deep plugging agent comprises the following components in percentage by mass: 20-50% of oil-containing sludge; 0.3%-1% of high temperature resistant polyacrylamide; 5%-15% of a modified polymeric monomer; 0.5%-1% of an organic cross-linking agent; 0.01%-0.05% of an initiator; 0.5%-1.5% of a reinforcing agent; 0.1%-0.3% of a deoxidant; and the balance of water. The total amount is 100%. The plugging agent can play a role in plugging a water flow dominant channel in a carbonate reservoir, the water injection effect is improved, and the crude oil recovery rate is increased. Meanwhile, the treatment cost of the oil field on the oily sludge is reduced, and the pollution of the oily sludge to the environment is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas field development, and in particular belongs to a temperature-resistant and salt-resistant oily sludge deep plugging agent and a preparation method thereof. Background Art

[0002] In the process of oil extraction, oily sludge is an inevitable associated solid waste. Its main sources are storage tanks, construction work, transportation, and ground sludge. Its main components are crude oil, mud and water, and it contains wastes such as benzene, phenols, asphaltene, mineral particles, etc. It is accompanied by a foul odor and has become an important factor affecting the environment.

[0003] At present, the main technologies for treating oily sludge include heat treatment, biological treatment, microwave radiation, solvent extraction, solidification treatment, reinjection and profile control, etc. Among them, the reinjection and profile control method takes advantage of the good compatibility of oily sludge with the formation, which not only solves the pollution problem of oily sludge, but also realizes resource utilization, and has become a research hotspot.

[0004] The most widely used systems are oily sludge suspension profile control system and organic gel type oily sludge profile control system. The content of oily sludge components is crucial for profile control and water plugging. Among them, oily sludge with high mud content is mainly used to prepare oily sludge emulsified suspension system. By suspending oily sludge particles, the suspension time is extended, the injection depth is increased, and the plugging strength is improved. Certain additives are added to form a uniform and stable emulsion, which enters the formation and absorbs the wax particles through the mud, and forms large particles through adhesion and aggregation, which plays a plugging role in the dominant channel of formation water flow.

[0005] The organic gel type oily sludge system is mainly formed by mixing and cross-linking oily sludge with polymers to form a gel system with certain strength and carrying capacity. With oily sludge as the main agent, after suspension screening experiments on different types of dispersants such as surfactants, alkalis, inorganic salts, and CMC (carboxymethyl cellulose), NPAM (non-ionic polyacrylamide), SNF (an acrylic acid polymer) and modified polyacrylamide potassium salt, dispersants and suspending agents are selected to develop a gel type oily sludge profile control system. The gel system has ductile toughness and viscoelasticity. After profile control, the water content is reduced from 98% to 92%, the displacement pressure gradient is increased from 0.15MPa / m to 5.7MPa / m, and the final recovery rate is increased by 5.5%. The profile control agent can achieve a good profile control and plugging effect.

[0006] However, with the deepening of the development of carbonate fractured oil reservoirs, the reservoirs tend to be high temperature and high salinity, and the applied plugging agents are required to have good injectivity and strength. However, the above-mentioned profile control agents have insufficient plugging strength and short effective period under high temperature and high salinity formation conditions. Summary of the invention

[0007] In order to solve the problems existing in the prior art, the present invention provides a temperature-resistant and salt-resistant oily sludge deep plugging agent and a preparation method thereof, which can block the dominant water flow channel in carbonate oil reservoirs, improve the water injection effect, and increase the crude oil recovery rate. At the same time, it reduces the treatment cost of oily sludge in oil fields and reduces the pollution of oily sludge to the environment.

[0008] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: a heat-resistant and salt-resistant oily sludge deep plugging agent, which comprises, by mass fraction, 20% to 50% of oily sludge; 0.3% to 1% of high-temperature resistant polyacrylamide; 5% to 15% of modified polymerization monomer; 0.5% to 1% of organic cross-linking agent; 0.01% to 0.05% of initiator; 0.5% to 1.5% of enhancer; 0.1% to 0.3% of deoxidizer; the rest is water; the total amount is 100%.

[0009] Furthermore, the water is formation water.

[0010] Furthermore, it also includes a bactericide, and the bactericide is formaldehyde.

[0011] Furthermore, the high temperature resistant polyacrylamide is obtained by hydrolysis and copolymerization of polyacrylamide and modified acrylamide monomers.

[0012] Furthermore, the high temperature resistant polyacrylamide is a non-ionic polymer, and the molecular weight includes one or two of 6 million, 8 million, and 15 million.

[0013] Furthermore, the modified polymer monomer is one or both of acrylamide and 2-acrylamide-2-methylpropanesulfonic acid.

[0014] Furthermore, the organic cross-linking agent includes a phenolic cross-linking agent and a silane cross-linking agent; the reinforcing agent includes one or two of montmorillonite and modified starch; and the deoxidizing agent is thiourea.

[0015] Furthermore, the initiator includes one or more of potassium persulfate, ammonium persulfate, and sodium bisulfite.

[0016] Furthermore, the oily sludge has a sludge content of 20% to 50%.

[0017] The present invention provides a method for preparing a heat-resistant and salt-resistant oily sludge deep plugging agent, and the specific steps are as follows:

[0018] S1: mixing the oily sludge and formation water evenly to obtain an oily sludge mixed liquid;

[0019] S2: adding high temperature resistant polyacrylamide into the oily sludge mixed liquid to prepare an oily sludge polymer base liquid;

[0020] S3 adding modified polymerization monomers to the oily sludge polymer base liquid to prepare a uniform and stable solution system;

[0021] S4 adds an organic cross-linking agent, a reinforcing agent, and an oxygen scavenger into the solution system, and finally adds an initiator and stirs evenly to obtain a heat-resistant and salt-resistant oily sludge deep plugging agent.

[0022] Compared with the prior art, the present invention has at least the following beneficial effects:

[0023] The present invention provides a heat-resistant and salt-resistant oily sludge deep plugging agent, which selects high-temperature resistant polyacrylamide and modified polymer monomers for cross-linking polymerization and then gelation. The gel system can be used as a good carrier of oily sludge. The oily sludge in the reaction system forms an electron pairing with the carboxyl group generated by polymer hydrolysis, so that it is bound to the polymer molecular chain; in addition, the sludge forms an electron pairing with the cations in the formation water due to its negative charge, and the formed particle precipitation is also bound to the polymer molecular chain, thereby forming a stable gel state. Further, the cross-linking of high-temperature resistant polyacrylamide to form a gel still mainly depends on the carboxyl group on the molecular chain, and the formation of a pairing between the positively charged microparticles and the carboxyl group requires the sacrifice of a certain amount of carboxyl groups. Therefore, the fusion of the polymer and the oily sludge and its gelation require the control of the amount of each component, and finally form an oily sludge gel system with good fusion and sufficient strength. The present invention adopts high temperature resistant polymer and modified polymer monomer polymerization, adds cross-linking agent to polymerize and cross-link in two ways, plays the role of temperature resistance and salt resistance, adds organic cross-linking agent, and reinforcing agent to further enhance the strength of oily sludge plugging agent, can achieve the purpose of deep plugging and obtain good plugging effect on on-site oily sludge.

[0024] The plugging agent of the present invention has a temperature resistance of 140°C and a salt resistance of 2.4×10 5 mg / L, no dehydration for 270 days, high strength, can reach level I or above, can achieve the requirement of blocking the dominant water flow channel, indoor evaluation 40MPa blocking rate of 100%, with good gelling effect and blocking effect, the sludge content in the oily sludge it treats ranges from 20 to 50%, and the injection viscosity is 100 to 150mPa·s, which meets the requirements of deep profile control of carbonate reservoirs, solves the problem of high water content in oil fields, and also realizes the resource utilization of oily sludge, solves environmental problems, and reduces oil field production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Electron microscopic image of TLT-1 system at 3000×;

[0026] Figure 2 Electron microscopic image of TLT-1 system at 6000×;

[0027] Figure 3 TLT-1 system salt tolerance evaluation chart;

[0028] Figure 4 TLT-1 system temperature resistance performance evaluation chart;

[0029] Figure 5 Viscosity-time curve of TLT-1 system;

[0030] Figure 6 The pressure and time curve of the plugging rate determination of the TLT-1 system;

[0031] Figure 7 TLT-1 system breakthrough process curve;

[0032] Figure 8 Curve diagram of oil displacement experiment with injection and adjustment agent;

[0033] Fig. 9 Statistical chart of the effects before and after water plugging in HA601-6 well. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0035] The invention provides a heat-resistant and salt-resistant oily sludge deep plugging agent, which comprises, by mass fraction, 20% to 50% of oily sludge; 0.3% to 1% of high-temperature resistant polyacrylamide; 5% to 15% of modified polymerization monomer; 0.5% to 1% of organic cross-linking agent; 0.01% to 0.05% of initiator; 0.5% to 1.5% of enhancer; and 0.1% to 0.3% of deoxidizer.

[0036] Furthermore, its components also include an appropriate amount of formation water, and the total amount of the temperature-resistant and salt-resistant oily sludge deep plugging agent is 100%.

[0037] Furthermore, its components also include an appropriate amount of bactericide, and the total amount of the heat-resistant and salt-resistant oily sludge deep plugging agent is 100%.

[0038] Preferably, the heat-resistant and salt-resistant oily sludge plugging agent comprises, by mass fraction, the following components: oily sludge: 25% to 40%; high temperature resistant polyacrylamide (polymer) 0.6% to 0.8%; modified polymerization monomer 8% to 12%; organic crosslinking agent 0.6% to 0.8%; initiator 0.02% to 0.04%; enhancer 0.8% to 1.3%; deoxidizer 0.1% to 0.2%;

[0039] Furthermore, its components also include an appropriate amount of formation water, and the total amount of the temperature-resistant and salt-resistant oily sludge deep plugging agent is 100%.

[0040] Furthermore, its components also include an appropriate amount of bactericide, and the total amount of the heat-resistant and salt-resistant oily sludge deep plugging agent is 100%.

[0041] Preferably, the high temperature resistant polyacrylamide is formed by hydrolysis copolymerization of polyacrylamide and modified acrylamide monomers. The high temperature resistant polyacrylamide has a high degree of hydrolysis. Although it is still a non-ionic polyacrylamide, part of the amide groups have been hydrolyzed into carboxylic acid groups, thereby improving its heat resistance.

[0042] High temperature resistant polyacrylamide is a non-ionic polymer with a molecular weight of one or two of 6 million, 8 million, and 15 million.

[0043] Furthermore, the modified polymer monomer is one or both of acrylamide and 2-acrylamide-2-methylpropanesulfonic acid. The addition of the modified polymer monomer further improves the heat and salt resistance of the plugging agent. Therefore, the heat and salt resistance of the plugging agent of the present invention is relatively high.

[0044] Furthermore, organic crosslinking agents include phenolic and silane graft crosslinking agents, and the like.

[0045] Furthermore, the initiator includes one or more of potassium persulfate, ammonium persulfate, and sodium bisulfite.

[0046] Furthermore, the reinforcing agent includes one or both of montmorillonite and modified starch.

[0047] Furthermore, the deoxidizer is thiourea, and the bactericide is preferably formaldehyde.

[0048] Preferably, the oily sludge of the present invention has a sludge content of 20 to 50%, preferably 30 to 40%.

[0049] The present invention also provides a method for preparing the above-mentioned heat-resistant and salt-resistant oily sludge plugging agent, which can be mixed evenly according to conventional methods in the art. Specifically, the method for preparing the above-mentioned heat-resistant and salt-resistant oily sludge plugging agent comprises the following steps:

[0050] 1) Mixing the oily sludge with an appropriate amount of formation water and stirring them evenly to obtain an oily sludge mixed liquid;

[0051] 2) adding the high temperature resistant polyacrylamide into the oily sludge mixed liquid of step 1) according to the above ratio to prepare an oily sludge polymer base liquid;

[0052] 3) Add the modified polymerization monomer into the oily sludge polymer base liquid according to the above ratio, stir and dissolve, and prepare a uniform and stable solution system.

[0053] 4) Adding an organic crosslinking agent, a reinforcing agent, and a deoxidizing agent to the solution system of step 3) according to the above ratio, and finally adding an initiator and stirring evenly to obtain a heat-resistant and salt-resistant oily sludge deep plugging agent.

[0054] The heat-resistant and salt-resistant oily sludge plugging agent prepared by the invention can be used in the process of oil production. It can be directly injected into the formation through the oil pipe of the oil tree after being pressurized by a pump truck, and gelled under high temperature conditions in the formation to achieve the effect of plugging formation cracks and high-permeability strips.

[0055] The mass fraction described in the present invention is a mass fraction known in the art, and may also be a multiple thereof, such as 1 / 10, 1 / 100, 10 times, 100 times, and the like.

[0056] Example 1

[0057] The heat-resistant and salt-resistant oily sludge plugging agent of the present invention comprises, by mass fraction, 30% of oily sludge, 0.6% of high-temperature-resistant polyacrylamide (polymer), 10% of acrylamide, 0.6% of phenolic crosslinking agent, 0.03% of potassium persulfate, 1.0% of montmorillonite, 0.1% of thiourea, and the remaining components are formation water, with a total amount of 100%.

[0058] The preparation of the heat-resistant and salt-resistant oily sludge plugging agent of the present invention comprises the following specific steps:

[0059] 1) Mixing the oily sludge with an appropriate amount of formation water and stirring them evenly to obtain an oily sludge mixed liquid;

[0060] 2) adding the high temperature resistant polyacrylamide into the oily sludge mixed liquid of step 1) according to the above ratio to prepare an oily sludge polymer base liquid;

[0061] 3) Add the modified polymerization monomer into the oily sludge polymer base liquid according to the above ratio, stir and dissolve, and prepare a uniform and stable solution system.

[0062] 4) Adding an organic crosslinking agent, a reinforcing agent, and a deoxidizing agent to the solution system of step 3) according to the above ratio, and finally adding an initiator and stirring evenly to obtain a heat-resistant and salt-resistant oily sludge deep plugging agent.

[0063] The heat-resistant and salt-resistant oily sludge deep plugging agent prepared in Example 1 is represented by TLT-1. It gels at 140°C, and the gelling time is controllable from 1h to 24h. No dehydration is observed after being kept at 140°C for 270d. The gel is dense, and the gel strength reaches above Grade I (visual code method). The viscosity is 105mPa·s. The salt resistance is 2.4×10 5 mg / L, breakthrough pressure 2565kPa / m, details are as follows:

[0064] 1) The microstructure of the TLT-1 flooding system was analyzed using a scanning electron microscope (SEM). Figure 1 , 2It can be seen that at 3000 times magnification, its microstructure presents a regular, dense three-dimensional network structure. When magnified to 6000 times, the regularity of its structure can be seen more clearly. The fine network structure is cross-linked in the larger tree-like structure, further enhancing the stability of the system.

[0065] 2) Evaluation of the salt tolerance of the TLT-1 flooding system of Example 1

[0066] The total mineralization of the formation water in the Halahatang reservoir is 2.11×10 5 mg / L, belonging to the CaCl2 water type, and diluted with Halahatang formation water to obtain a mineralization of 5×10 4 mg / L, 1×10 5 mg / L, 1.5×10 5 mg / L, 2.1×10 5 mg / L, self-prepared 2.4×10 5 mg / L formation water, using water of different mineralization degrees to prepare gel solutions, and observing the gelation at 140℃. Figure 3 As shown, it can be seen that the displacement systems under different salinities can all be gelled, and with the increase of salinity, the overall structure becomes more compact and the strength becomes higher.

[0067] 3) Evaluation of the temperature resistance of the TLT-1 flooding system of Example 1

[0068] The actual reservoir temperature of Halahatang can reach 170℃. The temperature was raised to 170℃ and maintained to observe the gelation of TLT-1 flooding system. Figure 4 As shown, the gelation was good and there was no dehydration after being kept at 170°C for 7 days.

[0069] 4) Evaluation of the apparent performance of the TLT-1 flooding system of Example 1

[0070] The total mineralization of the formation water in the Halahatang reservoir is 2.11×10 5 mg / L, belongs to CaCl2 water type, the TLT-1 flooding system is prepared with Halahatang formation water, put into a sealed vacuum ampoule bottle at 140℃ for gelation, and after the TLT-1 flooding system is gelled, it is taken out for extrusion test and tensile test, and the viscoelastic properties of the TLT-1 flooding system can be intuitively seen. Among them, the extrusion test: after being squeezed hard by hand, the system can be restored to its original state; the tensile test: after being stretched hard, the system is not broken and can be restored to its original state;

[0071] 5) Evaluation of injection performance of the TLT-1 flooding system of Example 1

[0072] The viscosity of polymer base liquid and TLT-1 drive modulator were measured respectively to provide a basis for the preparation and injection of on-site reagents. In order to more accurately simulate the temperature environment of the glue after injection into the wellbore, the continuous heating module of the high temperature and high pressure rheometer was used, the temperature change range of the pressure-sealed system was selected to be 30℃~140℃, and the measurement time was 7200s.

[0073] like Figure 5 As shown in the figure, the glue begins to thicken at 6 hours, and the temperature is about 90℃ at this time; when the temperature reaches 140℃ after 7 hours, the viscosity of TLT-1 displacement body is about 1500mPa·s. The results show that the system can meet the requirements of on-site injection, and the displacement system flows into large pores first, followed by small and medium pores.

[0074] 5) Evaluation of the plugging performance of the TLT-1 flooding system of Example 1

[0075] The high-temperature and high-pressure multifunctional core displacement test device is used to evaluate the plugging performance of the TLT-1 strong gel displacement system under simulated formation conditions.

[0076] The permeability of artificial core is calculated using Darcy's formula:

[0077] The calculation formula of plugging rate is:

[0078] Where, K-permeability, mdc; Q-flow, mg / l; P o - atmospheric pressure, kpA; μ-viscosity, cp; L-core length, cm; A-cross-sectional area, cm2; P1, P2-pressure, Kpa; K1, K2-permeability before and after plugging, mdc;

[0079] like Figure 6 As shown, during the displacement process, the 40 MPa pressure was not completely broken through, and the plugging rate was close to 100%. The experiment showed that the gel system had strong strength and plugging performance.

[0080] 6) Evaluation of the breakthrough pressure of the TLT-1 flooding system of Example 1

[0081] The high temperature and high pressure gel strength test device was used to evaluate the strength and adhesion performance of the flooding system and to test the breakthrough pressure of the flooding system. The breakthrough of the system was in the form of central bubbling, forming a water ball and finally rupturing, indicating that the gel had strong adhesion and strong flexibility to the stainless steel pipe wall, showing a certain compressive strength. Figure 7 As shown, the breakthrough pressure of the TLT-1 system with a tube length of 20 cm is 270.62 KPa.

[0082] 7) Evaluation of oil displacement performance of the TLT-1 displacement system of Example 1

[0083] The displacement device was used to evaluate the oil displacement effect of the temperature-resistant and salt-resistant displacement agent through a sand-filled pipe oil displacement experiment. The specific parameters are shown in Table 1:

[0084] Table 1 Parameters of sand-filled pipes for oil displacement experiments

[0085] serial number Experiment Type Diameter / cm Length / cm Porosity / % Permeability / mD Oil saturation / % 1 TLT-1 flooding 2.50 30.00 44.41 1697.28 91.79

[0086] In the experiment, the water injection rate was 0.20 mL / min, the viscosity reducer injection rate was 0.20 mL / min, and the water injection rate in the subsequent water flooding was 0.20 mL / min. The results of the oil displacement performance evaluation are shown in Figure 8 As shown, the experiment includes three stages. The first is the water flooding stage, at which the recovery rate is 24.67%. The second stage is the flooding stage with injection and adjustment of displacement agents, with a recovery rate of 36.83%. The third stage is the subsequent water flooding stage, with a recovery rate of 41.05%, and an increased recovery rate of 19.47%.

[0087] 7) The plugging agent of the present invention is used for flow regulation, water plugging and other recovery enhancement sites in ultra-deep, high-temperature and high-salt fracture-cavern carbonate rocks. The implementation effect is as follows: Fig. 9 It can be seen that from August 2 to September 2, the self-flowing (HA601-6 water plugging) increased oil production by 10 tons per day; on January 1, oil displacement (HA601-13) began, increasing oil production by 13 tons per day.

[0088] The stage oil production increased by 531 tons and the daily oil production increased by 10.62 tons. It is currently in the stage of lateral oil drive to increase production, with a casing pressure of 10Mpa and a daily output of 13 tons.

[0089] Example 2

[0090] The heat-resistant and salt-resistant oily sludge plugging agent of the present invention comprises, by mass fraction, 25% of oily sludge, 0.8% of high-temperature-resistant polyacrylamide (polymer), 8% of acrylamide, 0.8% of silane crosslinking agent, 0.02% of potassium persulfate, 0.8% of modified starch, 0.2% of thiourea, and the remaining components are formation water, with a total amount of 100%.

[0091] The rest is the same as Example 1.

[0092] Example 3

[0093] The heat-resistant and salt-resistant oily sludge plugging agent of the invention comprises, by mass fraction, 20% of oily sludge, 0.3% of high-temperature-resistant polyacrylamide (polymer), 15% of 2-acrylamide-2-methylpropanesulfonic acid, 1% of phenolic crosslinking agent, 0.01% of potassium persulfate and ammonium persulfate, 0.5% of montmorillonite and modified starch, 0.3% of thiourea, and the remaining components are formation water, with a total amount of 100%.

[0094] The rest is the same as the embodiment.

[0095] Example 4

[0096] The heat-resistant and salt-resistant oily sludge plugging agent of the present invention comprises, by mass fraction, 50% of oily sludge, 1% of high-temperature-resistant polyacrylamide (polymer), 5% of acrylamide and 2-acrylamide-2-methylpropane sulfonic acid, 1.5% of silane crosslinking agent, 0.05% of sodium bisulfite, 1.5% of montmorillonite, 0.2% of thiourea, and the remaining components are formation water, with a total amount of 100%.

[0097] The rest is the same as the embodiment.

[0098] Example 5

[0099] The heat-resistant and salt-resistant oily sludge plugging agent of the present invention comprises, by mass fraction, 40% of oily sludge, 0.7% of high-temperature-resistant polyacrylamide (polymer), 12% of 2-acrylamide-2-methylpropanesulfonic acid, 0.7% of phenolic crosslinking agent, 0.04% of ammonium persulfate, 1.3% of montmorillonite, 0.15% of thiourea, and the remaining components are formation water, with a total amount of 100%.

[0100] The rest is the same as the embodiment.

Claims

1. A heat-resistant and salt-resistant oily sludge deep plugging agent, characterized in that: Its components by mass fraction include: Oily sludge: 20% to 50%; high temperature resistant polyacrylamide 0.3% to 1%; modified polymerization monomer 5% to 15%; organic cross-linking agent 0.5% to 1%; initiator 0.01% to 0.05%; enhancer 0.5% to 1.5%; deoxidizer 0.1% to 0.3%; the rest is water; the total amount is 100%.

2. A heat-resistant and salt-resistant oily sludge deep plugging agent according to claim 1, characterized in that: The water is formation water.

3. According to claim 1, a heat-resistant and salt-resistant oily sludge deep plugging agent is characterized in that: Also included is a bactericide, which is formaldehyde.

4. The heat-resistant and salt-resistant oily sludge deep plugging agent according to claim 1, characterized in that: The high temperature resistant polyacrylamide is obtained by hydrolysis and copolymerization of polyacrylamide and modified acrylamide monomers.

5. The heat-resistant and salt-resistant oily sludge deep plugging agent according to claim 1, characterized in that: The high temperature resistant polyacrylamide is a non-ionic polymer, and the molecular weight includes one or two of 6 million, 8 million, and 15 million.

6. The heat-resistant and salt-resistant oily sludge deep plugging agent according to claim 1, characterized in that: The modified polymer monomer is one or both of acrylamide and 2-acrylamide-2-methylpropane sulfonic acid.

7. The heat-resistant and salt-resistant oily sludge deep plugging agent according to claim 1, characterized in that: The organic cross-linking agent includes a phenolic cross-linking agent and a silane cross-linking agent; the reinforcing agent includes one or two of montmorillonite and modified starch; and the deoxidizing agent is thiourea.

8. The heat-resistant and salt-resistant oily sludge deep plugging agent according to claim 1, characterized in that: The initiator includes one or more of potassium persulfate, ammonium persulfate, and sodium bisulfite.

9. The heat-resistant and salt-resistant oily sludge deep plugging agent according to claim 1, characterized in that: The oily sludge has a sludge content of 20% to 50%.

10. A heat-resistant and salt-resistant oily sludge deep plugging agent according to any one of claims 1 to 9, characterized in that: The specific steps are as follows: S1: mixing the oily sludge and formation water evenly to obtain an oily sludge mixed liquid; S2: adding high temperature resistant polyacrylamide into the oily sludge mixed liquid to prepare an oily sludge polymer base liquid; S3 adding modified polymerization monomers to the oily sludge polymer base liquid to prepare a uniform and stable solution system; S4 adds an organic cross-linking agent, a reinforcing agent, and an oxygen scavenger into the solution system, and finally adds an initiator and stirs evenly to obtain a heat-resistant and salt-resistant oily sludge deep plugging agent.

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