A sand control system and its application

Abstract

The present invention particularly relates to a sand control system and its application, belonging to the technical field of oil exploitation. The sand control system includes: an alcohol-based resin solution, the components of the alcohol-based resin solution include a solute and a solvent, the solute includes a resin binder, and the resin binder includes a thermosetting phenolic resin; and an aqueous foaming solution. By utilizing the high temperature resistance characteristic of the thermosetting phenolic resin and using the thermosetting phenolic resin as a raw material, the high temperature resistance performance of the sand control system preparation is improved, and the problem of the low high temperature resistance performance of the current foam resin sand control system is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil exploitation, and particularly relates to a sand control system and its application. Background Art

[0002] Sand production in oil and gas wells refers to the process or phenomenon in which, during the production process of oil wells or gas wells, due to various comprehensive factors such as geological conditions, exploitation methods, and measure operations, the rock structure near the bottom hole of the formation changes, resulting in the formation of discrete sand or exfoliated sand in the formation being carried by the formation produced fluid into the wellbore or the ground, thereby causing a series of adverse effects on the normal production of oil and gas wells.

[0003] The main way to solve the problem of sand production in oil and gas wells is to adopt sand control technology to prevent the formation produced sand from entering the wellbore or artificially strengthen the consolidation degree of the rock near the formation, so as to control the formation sand production. Among them, chemical sand control technology is to inject resin-based cementing agents into the formation to cement and solidify the loose sand grains to prevent the formation sand from being produced with the fluid. Chemical sand control technology is one of the widely used sand control technologies at present, and can effectively solve the problems of sand production in oil and gas wells such as heavy oil thermal recovery wells, casing damage wells, small hole wells, secondary sand control wells, fine silt oil reservoirs, and high shale oil reservoirs. Compared with other sand control technologies, this technology has the advantages of simple construction, no pipe string left, and low cost. However, the existing resin-based chemical sand control agents have problems such as high density, uneven injection, and large reservoir damage, resulting in a short sand control effective period and a decrease in production after sand control, severely limiting their application scale.

[0004] At present, it has been found that the use of a foam resin sand control system can, to a certain extent, solve the above problems, but the current foam resin sand control system has low high-temperature resistance and is difficult to meet the sand control requirements of heavy oil thermal recovery high-temperature wells (above 200 - 350 °C). Summary of the Invention

[0005] The purpose of the present application is to provide a sand control system and its application to solve the problem of low high-temperature resistance of the current foam resin sand control system.

[0006] An embodiment of the present invention provides a sand control system, which includes:

[0007] An alcohol-based resin solution, the components of the alcohol-based resin solution include a solute and a solvent, the solute includes a resin cementing agent, and the resin cementing agent includes a thermosetting phenolic resin; and

[0008] An aqueous foaming solution.

[0009] Optionally, the thermosetting phenolic resin includes at least one of 2127 phenolic resin, 2130 phenolic resin, 219 phenolic resin, and boron-modified phenolic resin.

[0010] Optionally, the thermosetting phenolic resin is a mixture of 2127 phenolic resin and 219 phenolic resin, wherein the mass ratio of the 2127 phenolic resin to the 219 phenolic resin is 1:1.

[0011] Optionally, the solute further includes a heat-resistant aid to improve the temperature resistance of the thermosetting phenolic resin.

[0012] Optionally, the heat-resistant aid includes coal tar pitch powder.

[0013] Optionally, the particle size of the coal tar pitch powder is ≤ 0.025 mm.

[0014] Optionally, the components of the alcohol-based resin solution include, by mass percentage: 55%-85% of resin binder, 10%-30% of solvent, and 5%-15% of heat-resistant aid.

[0015] Optionally, the solvent includes one of acetone, ethanol, ethyl acetate, ethylene glycol monobutyl ether, tetrahydrofuran, or chloroform.

[0016] Optionally, the mass ratio of the solute to the solvent is 80%:20%.

[0017] Optionally, the viscosity of the alcohol-based resin solution is 50 mPa·s - 200 mPa·s.

[0018] Optionally, the components of the water-based foaming solution include water, coupling agent, dispersant, foaming agent, and foam stabilizer.

[0019] Optionally, the foaming agent is an anionic surfactant and / or a silicone surfactant.

[0020] Optionally, the anionic surfactant includes at least one of sodium α-olefin sulfonate, sodium dodecyl sulfate, sodium dodecyl sulfonate, sodium dodecyl benzene sulfonate, lauramidopropyl betaine, lauramidopropyl hydroxysulfobetaine, coconut oil glutamic acid, and coconut oil amide propyl betaine.

[0021] Optionally, the foaming agent is a mixture of an anionic surfactant and a silicone surfactant, the anionic surfactant is sodium dodecyl sulfate, and the mass ratio of the sodium dodecyl sulfate to the silicone surfactant is 1:(0.5 - 1.0).

[0022] Optionally, the components of the water-based foaming solution include, by mass percentage: 98.8%-96.2% of water, 0.1%-0.3% of coupling agent, 0.3%-1.0% of dispersant, 0.5%-1.5% of foaming agent, and 0.3%-1.0% of foam stabilizer.

[0023] Optionally, the coupling agent is a silane coupling agent;

[0024] The dispersant is a non-ionic surfactant.

[0025] Optionally, the silane coupling agent includes at least one of KH550, KH560, KH570, KH792, DL602, and DL171;

[0026] The non-ionic surfactant includes at least one of OP-10, SP-80, Tween-60, and AE0-9;

[0027] The foam stabilizer includes at least one of silicone resin polyether, hydrophobic nano-SiO2, graphite powder, and dolomite powder.

[0028] Optionally, the mass ratio of the alcohol-based resin solution to the water-based foaming solution is 1:(0.8 - 1.2).

[0029] Based on the same inventive concept, an embodiment of the present invention also provides an application of the sand control system as described above, and the application includes using the sand control system for sand control treatment of heavy oil thermal recovery wells.

[0030] Based on the same inventive concept, an embodiment of the present invention also provides a sand control method, and the method includes:

[0031] Pre-treating the formation;

[0032] Performing foam mixing and plugging removal on the pre-treated formation;

[0033] Injecting foam resin into the formation after foam mixing and plugging removal;

[0034] Performing gas pore increasing on the bottom layer after injecting the foam resin, and then performing high-temperature steam curing; completing the sand control treatment;

[0035] Among them, the foam resin is the foam resin prepared from the sand control system as described above.

[0036] Optionally, in the preparation of the foam resin, the temperatures of the alcohol-based resin solution and the water-based foaming solution are 20°C - 60°C.

[0037] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0038] The sand control system provided by the embodiment of the present invention utilizes the high-temperature resistance characteristic of thermosetting phenolic resin, uses thermosetting phenolic resin as the raw material, improves the high-temperature resistance performance of the sand control system preparation, and solves the problem of low high-temperature resistance performance of the current foam resin sand control system.

[0039] The above description is only an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the content of the specification. And in order to make the above and other objects, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention are hereinafter specifically exemplified. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for the description of the embodiments. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to these drawings.

[0041] Figure 1 is a morphological diagram of the foam resin prepared by the sand control system provided in Embodiment 1 of the present invention;

[0042] Figure 2 is a schematic diagram of the on-site construction process of the high-temperature foam resin sand control provided in the embodiment of the present invention;

[0043] Figure 3 is a result diagram of the injection performance of the conventional resin sand consolidant and the foam resin sand consolidant provided in the embodiment of the present invention;

[0044] Figure 4 is a flowchart of the method provided in the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] The following will specifically describe the present invention in combination with specific embodiments and examples, and the advantages and various effects of the present invention will be presented more clearly therefrom. Those skilled in the art should understand that these specific embodiments and examples are used to illustrate the present invention, rather than to limit the present invention.

[0046] Throughout the specification, unless otherwise specifically stated, the terms used herein should be understood as having the meanings as commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as the general understanding of those skilled in the art to which the present invention belongs. In case of conflict, this specification prevails.

[0047] Unless otherwise specifically stated, all kinds of raw materials, reagents, instruments and equipment used in the present invention can be obtained through market purchase or can be prepared by existing methods.

[0048] The technical solution of the embodiment of the present application is to solve the above technical problems, and the general idea is as follows:

[0049] According to a typical embodiment of the present invention, a sand control system is provided, and the sand control system includes:

[0050] Alcohol-based resin solution (Agent A), the composition of the alcohol-based resin solution includes a solute and a solvent, the solute includes a resin binder, and the resin binder includes a thermosetting phenolic resin; and

[0051] Water-based foaming solution (Agent B).

[0052] With the above design, by utilizing the high-temperature resistance characteristic of the thermosetting phenolic resin and using the thermosetting phenolic resin as the raw material, the high-temperature resistance performance of the sand control system preparation is improved, and the problem of the low high-temperature resistance performance of the current foam resin sand control system is solved.

[0053] In some embodiments, the thermosetting phenolic resin includes at least one of 2127 phenolic resin, 2130 phenolic resin, 219 phenolic resin, and boron-modified phenolic resin.

[0054] More optimally, the thermosetting phenolic resin is a mixture of 2127 phenolic resin and 219 phenolic resin, wherein the mass ratio of the 2127 phenolic resin to the 219 phenolic resin is 1:1.

[0055] The 2127 phenolic resin and the 219 phenolic resin can be cured by high-temperature steam, have high-temperature resistance characteristics, wide raw material sources, and appropriate prices.

[0056] In order to further improve the temperature resistance performance and consolidation strength of the thermosetting phenolic resin, in some embodiments, the solute further includes a heat-resistant additive.

[0057] In this embodiment, the heat-resistant additive includes coal tar pitch powder.

[0058] Coal tar pitch powder is a heterocyclic chemical raw material, a compound rich in gum and asphaltene, with good temperature resistance. It has a similar structure to the above resin and can undergo a chemical reaction with phenolic resin at high temperatures to be converted into high-temperature-resistant coke and pitch coke, thereby achieving the purpose of improving the temperature resistance performance of phenolic resin. Therefore, coal tar pitch powder can be selected as the heat-resistant additive in this embodiment.

[0059] Compared with the prior art that uses coal tar as the heat-resistant additive, coal tar is easy to adsorb on the surface of sand grains to form an oil film, thus affecting the adsorption performance of phenolic resin on the surface of sand grains, while coal tar pitch powder does not affect the adsorption performance of phenolic resin on the surface of sand grains and can ensure the high-strength adsorption of phenolic resin and formation sand.

[0060] In order to prevent coal tar pitch powder from blocking the formation during injection, more optimally, the particle size of the coal tar pitch powder is below 500 mesh, in other words, the particle size ≤ 0.025 mm.

[0061] Specifically, the composition of the alcohol-based resin solution includes, by mass percentage: resin binder 55% - 85%, solvent 10% - 30%, and heat-resistant additive 5% - 15%.

[0062] Phenolic resin has a high viscosity and is insoluble in water. A solvent needs to be used for dilution to facilitate its dispersion in water. In some embodiments, the solvent includes one of acetone, ethanol, ethyl acetate, ethylene glycol monobutyl ether, tetrahydrofuran, or chloroform. Preferably, ethanol is used as the solvent. Ethanol solvent is safe, non-toxic, and has an appropriate price.

[0063] In some embodiments, the mass ratio of the solute to the solvent is 80%:20%.

[0064] In some embodiments, the viscosity of the alcohol-based resin solution is 50 mPa·s - 200 mPa·s.

[0065] Alcohol-soluble phenolic resin (i.e., thermosetting phenolic resin) has high-temperature resistance characteristics, but it is very difficult to produce stable foam in an aqueous system. Similar phenolic resin foams have not been seen in the currently available public information. There are mainly two major difficulties in the foaming of alcohol-soluble phenolic resin: one is that phenolic resin has poor water solubility and high viscosity. After encountering water, oligomers and free phenols will be generated due to uneven degree of polymerization, resulting in phenomena such as whitening, agglomeration, and wall hanging, and its dispersibility in water is extremely poor; the other is that the alcohol-based solvent used in phenolic resin is generally weakly polar and is easily adsorbed on the gas-liquid interface, reducing the surface tension of the system and affecting the stability of the foam.

[0066] To overcome the problem of its difficulty in generating stable foam, the applicant has found that the following aqueous foaming solution can solve the problem.

[0067] In some embodiments, the components of the aqueous foaming solution include water, coupling agent, dispersant, foaming agent, and foam stabilizer.

[0068] In this embodiment, the components of the aqueous foaming solution include, by mass percentage, 98.8% - 96.2% of water, 0.1% - 0.3% of coupling agent, 0.3% - 1.0% of dispersant, 0.5% - 1.5% of foaming agent, and 0.3% - 1.0% of foam stabilizer.

[0069] In some embodiments, the foaming agent is an anionic surfactant and / or a silicone surfactant.

[0070] In some embodiments, the anionic surfactant includes at least one of sodium α-olefin sulfonate (AOS), sodium dodecyl sulfate (SDS), sodium dodecyl sulfonate, sodium dodecyl benzene sulfonate, lauramidopropyl betaine (LAB-35), lauramidopropyl hydroxysulfobetaine (LHSB), coconut oil glutamic acid, and coconut oil amide propyl betaine (CAB-35).

[0071] More preferably, the foaming agent is a mixture of an anionic surfactant and a silicone surfactant. The anionic surfactant is sodium dodecyl sulfate, and the mass ratio of the sodium dodecyl sulfate to the silicone surfactant is 1:(0.5 - 1.0).

[0072] During the invention process, the applicant found that: by compounding an anionic surfactant and a silicone surfactant as the foaming agent for phenolic resin in an alcohol-based solvent - aqueous solution system, high-temperature phenolic resin foam with good foaming effect, good stability, and high foam quality can be generated according to the above formula.

[0073] Sodium dodecyl sulfate (SDS) adsorbs at the gas / liquid interface, reducing the surface tension between the gas and liquid phases to form foam.

[0074] In some embodiments, the coupling agent is a silane coupling agent;

[0075] The dispersant is a non-ionic surfactant.

[0076] Specifically, the silane coupling agent includes at least one of KH550, KH560, KH570, KH792, DL602, and DL171; preferably, the coupling agent is KH550.

[0077] The coupling agent can change the surface properties of formation sand grains, increase the affinity between phenolic resin and formation sand, and improve the bonding strength of consolidated formation sand.

[0078] The non-ionic surfactant includes at least one of OP-10, SP-80, Tween-60, and AE0-9; preferably, the dispersant is OP-10.

[0079] The dispersant can disperse the resin binder in water in the form of fine particles.

[0080] The foam stabilizer includes at least one of silicone resin polyether, hydrophobic nano-SiO2, graphite powder, and dolomite powder. Preferably, the foam stabilizer is hydrophobic nano-SiO2.

[0081] Nano-SiO2 particles can increase the strength of the foam liquid film, improve the foam stability, and at the same time can combine with phenolic resin to improve the consolidation strength and temperature resistance of phenolic resin.

[0082] Preferably, the formula of the high-temperature foam resin sand control system provided by the present invention is as follows:

[0083] Agent A: 35% 2127 phenolic resin + 35% 219 phenolic resin + 20% ethanol + 10% coal tar pitch powder

[0084] Agent B: 95% clear water + 0.2% coupling agent KH550 + 0.3% dispersant OP-10 + 0.4% foaming agent SDS + 0.4% silicone surfactant + 0.4% graphite powder

[0085] At room temperature, mix the above resin binder, solvent and heat-resistant auxiliary evenly, and dilute them into an alcohol-based resin solution with a viscosity of 50 - 200 mPa·s to prepare Agent A, which is sealed and stored. At the same time, prepare Agent B according to the above formula, and then a high-temperature foam resin sand control system is obtained. Mix and stir Agent A and Agent B in a ratio of 1∶(0.8 - 1.2), and high-temperature foam resin can be generated. Preferably, Agent A and Agent B are mixed and stirred in a ratio of 1∶1.

[0086] During on-site construction mixing and stirring, the temperatures of Agent A and Agent B should be between 20°C and 60°C. Preferably, the temperature of Agent B should be between 50 - 60°C, which is more conducive to the dispersion of phenolic resin and prevents its aggregation.

[0087] This high-temperature foam resin has the following technical parameters: foaming volume is 3 - 7 times; foam density is 0.35 - 0.65 g / cm 3 ; half-life at room temperature is 30 h; half-life at 60°C is 5 h; curing temperature is above 120°C; temperature resistance is above 300°C.

[0088] According to another typical embodiment of the present invention, an application of the above-mentioned sand control system is provided, and the application includes using the sand control system for sand control treatment of heavy oil thermal recovery wells.

[0089] According to another typical embodiment of the present invention, a sand control method is provided, and the method includes:

[0090] S1. Pretreat the formation;

[0091] S2. Conduct foam mixing and plugging removal on the pretreated formation;

[0092] S3. Inject foam resin into the formation after foam mixing and plugging removal; the foam resin is the foam resin prepared from the above-mentioned sand control system;

[0093] In some embodiments, the temperatures of the alcohol-based resin solution and the water-based foaming solution are 20°C - 60°C.

[0094] S4. Conduct gas pore increasing on the formation after injecting the foam resin, and then conduct high-temperature steam curing; complete the sand control treatment;

[0095] Specifically, in this embodiment, according to the above formula, Agent A and Agent B are respectively prepared and filled into different containers for on-site construction. The supporting equipment required for on-site construction mainly includes a cement truck, a nitrogen injection truck, a mixing tank, and a foam generator. The construction is carried out according to the following steps:

[0096] (1) Formation pretreatment: Use a cement truck to inject a preflush fluid into the formation. The preflush fluid uses produced water from the oilfield or tap water, and a washing oil agent, an anionic foaming agent, and an anti-swelling agent are added to clean the oil stain on the surface of sand grains and simultaneously perform an anti-swelling treatment on clay minerals.

[0097] (2) Foam mixing and plugging removal: Inject high-pressure nitrogen using a nitrogen injection truck. When the wellhead pressure reaches above 2 MPa, open the wellhead valve for blowout to discharge fine sand, argillaceous minerals, and other blockages in the formation. Repeatedly inject the preflush fluid and high-pressure nitrogen and perform blowout until there are no impurities in the produced fluid.

[0098] (3) Injecting foam resin: Pour Agent A and Agent B into the mixing tank, stir evenly to obtain a mixed solution, use a cement truck to inject the mixed solution into the foam generator, and at the same time use a nitrogen injection truck to inject high-pressure nitrogen into the foam generator to generate foam resin. Use the combined pressure of the cement truck and the nitrogen injection truck to inject the foam resin into the formation.

[0099] (4) Gas pore increasing: Inject high-pressure nitrogen using a nitrogen injection truck for pore increasing to displace the excess phenolic resin in the pores of the formation rock.

[0100] (5) High-temperature steam curing: Use the existing steam injection equipment in the heavy oil thermal recovery well to inject high-temperature steam into the formation to cure the phenolic resin and complete the sand control construction.

[0101] Preferably, the sand control treatment can be carried out during the steam stimulation cycle of the oil well, after stopping steam injection and before starting production, using the original steam injection string for construction.

[0102] Hereinafter, the sand control system and its application of the present application will be described in detail with reference to examples, comparative examples, and experimental data.

[0103] It should be noted that in each example, the 2127 phenolic resin is purchased from Jining Baichuan Chemical Co., Ltd., and the 219 phenolic resin is purchased from Liaoning Jincheng Chemical Co., Ltd.

[0104] Example 1

[0105] A preparation method of a sand control system, the method comprising:

[0106] At room temperature, take 35 parts of 2127 phenolic resin, 35 parts of 219 phenolic resin, 20 parts of ethanol, and 10 parts of coal tar pitch powder, pour them into a container, stir evenly, and fully dissolve and dilute to form Agent A within 200 mPa·s, and store it sealed.

[0107] Take 85 parts of tap water, add 0.2 part of coupling agent KH550, 0.3 part of dispersant OP-10, 0.4 part of foaming agent SDS, 0.4 part of silicone surfactant, and 0.4 part of graphite powder, mix and stir, fully dissolve, and prepare Agent B, which is stored in a sealed manner.

[0108] Example 2

[0109] A preparation method of a sand control system, the method comprising:

[0110] At room temperature environment, take 70 parts of 2127 phenolic resin, 20 parts of ethanol and 10 parts of coal tar pitch powder, pour them into a container, stir evenly, and fully dissolve and dilute to Agent A within 200 mPa·s, which is stored in a sealed manner.

[0111] Take 85 parts of tap water, add 0.2 part of coupling agent KH550, 0.3 part of dispersant OP-10, 0.4 part of foaming agent SDS, 0.4 part of silicone surfactant, and 0.4 part of graphite powder, mix and stir, fully dissolve, and prepare Agent B, which is stored in a sealed manner.

[0112] Example 3

[0113] A preparation method of a sand control system, the method comprising:

[0114] At room temperature environment, take 60 parts of 219 phenolic resin, 30 parts of ethanol and 10 parts of coal tar pitch powder, pour them into a container, stir evenly, and fully dissolve and dilute to Agent A within 200 mPa·s, which is stored in a sealed manner.

[0115] Take 85 parts of tap water, add 0.2 part of coupling agent KH550, 0.3 part of dispersant OP-10, 0.4 part of foaming agent SDS, 0.4 part of silicone surfactant, and 0.4 part of graphite powder, mix and stir, fully dissolve, and prepare Agent B, which is stored in a sealed manner.

[0116] Example 4

[0117] A sand control method, the method comprising:

[0118] Load the prepared Agent A and Agent B into different containers and transport them to the construction site. The supporting equipment required for on-site construction mainly includes a 700-type cement truck, a 1200-type nitrogen injection truck, a 1 m 3 mixing tank, a foam generator with a pressure resistance of 35 MPa, a liquid tank truck, etc. Connect the ground construction process as Figure 2 shown.

[0119] Carry out the construction according to the following steps:

[0120] (1)Stratum pretreatment: Use a cement truck to inject a preflush fluid into the stratum. The preflush fluid uses produced water from the oilfield or tap water, and a washing agent, an anionic foaming agent a-olefin sulfonate, and an anti-swelling agent KCl are added to clean the oil stain on the surface of sand grains and perform an anti-swelling treatment on clay minerals at the same time.

[0121] (2)Foam mixed displacement and plugging removal: Use a nitrogen injection truck to inject high-pressure nitrogen at a displacement of 500 - 1100 m 3 / h. When the wellhead pressure reaches above 2 MPa, open the wellhead valve for blowout to discharge fine sand, argillaceous minerals, and other plugging substances in the stratum. Repeatedly inject the preflush fluid and high-pressure nitrogen and perform blowout until there are no impurities in the produced fluid.

[0122] (3)Inject foam resin: Pour agent A and agent B into a mixing tank, stir evenly to obtain a mixed solution, and use a cement truck to inject the mixed solution into a foam generator at a displacement of 0.3 - 0.8 m 3 / min. At the same time, use a nitrogen injection truck to inject high-pressure nitrogen into the foam generator at a displacement of 0.5 - 20 m 3 / min to generate foam resin. Use the combined pressure of the cement truck and the nitrogen injection truck to inject the foam resin into the stratum.

[0123] (4)Gas pore enlargement: Pause the cement truck, and use the nitrogen injection truck to continue injecting 250 - 800 m 3 of high-pressure nitrogen for pore enlargement to displace the excess phenolic resin in the pores of the formation rock.

[0124] (5)High-temperature steam curing: Use the existing steam injection equipment in the heavy oil thermal recovery well to inject high-temperature steam into the stratum to cure the phenolic resin and complete the sand control construction.

[0125] Comparative Example 1

[0126] This comparative example uses a conventional resin. Specifically, the conventional resin is a tar-modified phenolic resin.

[0127] Experimental Example 1

[0128] Evaluate the performance of the high-temperature foam resin sand control systems prepared in Example 1, Example 2, Example 3, and Comparative Example 1 according to the following experimental methods:

[0129] (1)Experimental conditions

[0130] a. 60 - 80 mesh formation sand

[0131] b. Φ25×50 mm glass tube

[0132] c. Vacuum filtration experimental instrument

[0133] d. Handheld stirrer

[0134] e. High-temperature oven

[0135] f. Permeability tester

[0136] g. Material mechanics testing machine

[0137] h. High-temperature aging tank

[0138] (2)Experimental steps

[0139] a. Place the glass tube into the vacuum filtration experiment instrument;

[0140] b. Take 50 g of formation sand and load it into the glass tube, compact it, and pour in clear water to moisten it;

[0141] c. Take 10 g of Agent A and 10 g of Agent B, pour them into a beaker, and use a hand-held stirrer to stir at a speed of 600 r / min for 30 s to form a uniform foam resin;

[0142] d. Use the vacuum filtration experiment instrument to suck the foam resin into the glass tube to completely immerse the formation sand;

[0143] e. After all the foam resin is sucked out, continue to suck air for 10 s to increase the pores with gas;

[0144] f. After compacting and sealing both ends of the glass tube with metal filter screens, place it in a 120 °C high-temperature oven for curing for 12 h;

[0145] g. Take out the glass tube, gently break it to obtain a consolidated core, level both ends, and test the permeability and compressive strength values of the core;

[0146] h. Repeat the above steps to make another core, put it into the high-temperature aging tank, add an aqueous solution with pH = 10, seal it, and then put it into a 300 °C high-temperature oven for aging for 11 days. Take out the core and test the permeability and compressive strength after high-temperature aging.

[0147] The experimental results are shown in Table 1.

[0148] Table 1 Data table of experimental test results for examples

[0149]

[0150] Experimental Example 2

[0151] In order to verify whether the foam resin can achieve the purpose of adjusting the injection profile and realizing uniform sand consolidation. The injection performance of conventional resin sand consolidants and foam resin sand consolidants in heterogeneous formations was tested. Two glass tubes were used, filled with formation sand of different particle sizes respectively, to simulate high-permeability layers and low-permeability layers, and then conventional resin and foam resin were injected respectively to observe the uniformity of the sand consolidant injection, as Figure 3As shown in the figure, it should be noted that the glass tube on the left in each small box in the figure is the simulation of the low-permeability layer, and the glass tube on the right is the simulation of the high-permeability layer; the recording times of each small box from left to right are 10s, 30s, and 60s respectively, and the length of the strip on the right side of the glass tube represents the injection depth of the sand consolidant.

[0152] From the experimental results: During the injection process of conventional resin, fingering phenomenon is obvious, and the injection depth difference between high and low permeability layers is very large. While foam resin can cause plugging in the high-permeability layer to prevent the occurrence of fingering phenomenon; at the same time, increasing the injection pressure can increase the injection volume and injection depth of the medium and low permeability layers. Thus, the injection profile of the heterogeneous oil reservoir is improved, that is, the resin utilization rate is increased, and the sand consolidation effect of the medium and low permeability layers is ensured.

[0153] Experimental Example 3

[0154] Well Du 84-XX-XX is located in the west of Xinglongtai in Du 84, belonging to an extra-heavy oil well with slight sand production. The thickness of the production interval is 21.4m / 7 layers. Before the measures, the total production time in two cycles was 405.6 days, the sand sticking and pump checking were carried out 2 times, the cumulative oil production was 835t, and the liquid production was 7727m 3 . In May 2020, the high-temperature foam resin sand control technology was implemented on site, 4t of Agent A and Agent B were pumped respectively. The pump was put into production on February 20, 2019. As of May 12, 2021, it has been continuously produced for 804 days, with a cumulative oil production of 4766t and a liquid production of 14240m 3 . The increased production is 3931t.

[0155] One or more technical solutions in the embodiments of the present invention at least further have the following technical effects or advantages:

[0156] (1) The sand control system provided by the embodiments of the present invention utilizes the high-temperature resistance characteristic of thermosetting phenolic resin. Using thermosetting phenolic resin as the raw material, it improves the high-temperature resistance performance of the sand control system preparation, and solves the problem of low high-temperature resistance performance of the current foam resin sand control system;

[0157] (2) The sand control system provided by the embodiments of the present invention solves the problem of phenolic resin foaming, and improves the temperature resistance performance of phenolic resin through temperature-resistant additives, realizing the requirements of high-temperature foam resin sand control in heavy oil thermal recovery wells;

[0158] (3) The sand control system provided by the embodiments of the present invention utilizes the Jamin effect of foam resin to plug the high-permeability layer, prevent the occurrence of fingering phenomenon, increase the injection pressure of the medium and low permeability layers, realize uniform injection of high, medium and low permeability layers, ensure the sand consolidation effect of each layer, and improve the sand consolidation strength;

[0159] (4) The sand control system provided by the embodiments of the present invention utilizes the volume increase effect and uniform sand consolidation effect of foam resin to improve the utilization rate of phenolic resin, reduce the dosage of phenolic resin, and reduce the sand control cost;

[0160] (5) Compared with the conventional chemical sand control that uses liquid pore enlargement, the sand control method provided by the embodiments of the present invention uses gas pore enlargement, and the pores in the rock are filled with bubbles, which is more conducive to the pore enlargement effect, can reduce the residue of phenolic resin in the pores, and reduce reservoir damage;

[0161] (6) The raw material cost of the sand control system provided by the embodiments of the present invention is low, and the construction process is simple, which can meet the sand control requirements of long well sections, heterogeneous formations, multi-layer oil reservoirs, horizontal wells, and casing damaged wells, improve the overall sand control effect of oil wells, extend the effective period of sand control, and greatly expand the application range of chemical sand control technology.

[0162] Finally, it should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device.

[0163] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0164] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A sand control system, characterized in that, The sand control system includes: an alcohol-based resin solution, the components of the alcohol-based resin solution including, by mass percentage: 55%-85% of a resin binder, 10%-30% of a solvent, and 5%-15% of a heat-resistant additive; and an aqueous foaming solution, the components of the aqueous foaming solution including, by mass percentage: 98.8%-96.2% of water, 0.1%-0.3% of a coupling agent, 0.3%-1.0% of a dispersant, 0.5%-1.5% of a foaming agent, and 0.3%-1.0% of a foam stabilizer; wherein, the resin binder is a mixture of 2127 phenolic resin and 219 phenolic resin with a mass ratio of 1:1; the heat-resistant additive is coal tar pitch powder with a particle size ≤ 0.025 mm; the foaming agent is a mixture of sodium dodecyl sulfate and a silicone surfactant with a mass ratio of 1:(0.5-1.0); the mass ratio of the alcohol-based resin solution to the aqueous foaming solution is 1:(0.8-1.2).

2. The sand control system according to claim 1, characterized in that, The solvent includes one of acetone, ethanol, ethyl acetate, ethylene glycol monobutyl ether, tetrahydrofuran, or chloroform.

3. The sand control system according to claim 1, characterized in that, The viscosity of the alcohol-based resin solution is 50 mPa·s - 200 mPa·s.

4. The sand control system according to claim 1, wherein, The coupling agent is a silane coupling agent; The dispersant is a non-ionic surfactant.

5. The sand control system according to claim 4, characterized in that, The silane coupling agent includes at least one of KH550, KH560, KH570, KH792, DL602, and DL171; The non-ionic surfactant includes at least one of OP-10, SP-80, Tween-60, and AE0-9; The foam stabilizer includes at least one of silicone resin polyether, hydrophobic nano-SiO2, graphite powder, and dolomite powder.

6. Use of a sand control system according to any one of claims 1 to 5, characterized in that The application includes using the sand control system in the sand control treatment of heavy oil thermal recovery wells.

7. A sand control method, characterized in that, The method includes: performing pretreatment on the formation; performing foam mixing and plugging removal on the pretreated formation; injecting foam resin into the formation after foam mixing and plugging removal; performing gas pore increasing on the formation after injecting the foam resin, and then performing high-temperature steam curing; completing the sand control treatment; wherein, the foam resin is the foam resin prepared from the sand control system according to any one of claims 1 to 5.

8. The sand control method according to claim 7, characterized in that, In the preparation of the foam resin, the temperatures of the alcohol-based resin solution and the aqueous foaming solution are 20°C - 60°C.

Images