Self-adaptive sand control screen pipe for weakly cemented reservoir oil and gas well as well as preparation method and application of self-adaptive sand control screen pipe

Abstract

The invention discloses a self-adaptive sand control screen pipe for a weakly cemented reservoir oil and gas well and a preparation method and application thereof, and belongs to the technical field of oil and gas resource exploitation, and the self-adaptive sand control screen pipe sequentially comprises an electric heating base pipe, a self-adaptive high-molecular polymer layer and a protective coating layer from inside to outside. The invention further discloses a preparation method of the self-adaptive sand control screen pipe and application of the self-adaptive sand control screen pipe in a weakly cemented reservoir. The problems of wellbore blockage, near-wellbore stratum collapse and the like when an existing sand prevention mode is applied to mining wells of weakly cemented oil and gas reservoirs such as muddy silt are solved, and improvement is carried out aiming at the situation that an existing organic high-molecular polymer material cannot meet the long-term sand prevention requirement of an unconventional oil and gas reservoir underground.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas resource exploitation, and in particular relates to an adaptive sand control screen pipe for weakly cemented reservoir oil and gas wells, and a preparation method and application thereof. Background Art

[0002] During the development of weakly cemented reservoir oil and gas, a significant pressure drop will cause changes in the mechanical properties of the formation, which will cause wellbore instability and other phenomena that reduce the production efficiency and may also cause other associated geological disasters. Formation sand production is a phenomenon in which soft, fine-grained silt and muddy silt migrate with gas to the near-wellbore and block the gas pipeline during the oil and gas resource extraction process. At present, most of the weakly cemented reservoir oil and gas extraction methods are faced with the problems of sand production and near-wellbore blockage. Therefore, how to achieve effective sand control technology is the key to this type of oil and gas development.

[0003] In terms of sand prevention and control, the current sand prevention methods for conventional oil and gas resource exploitation include wire-wound screen sand prevention, gravel packing sand prevention and chemical sand prevention. However, in practice, the gravel packing sand prevention method has been proven to be unsuitable for oil and gas reservoirs with weakly cemented reservoirs, resulting in serious sand production and near-well collapse, blocking the seepage channel, affecting gas and water production, and reducing production capacity. In addition, when chemical sand consolidation is applied to oil and gas reservoirs with high clay content, there will be problems such as low curing strength, which will affect the sand prevention effect. It can be seen that traditional sand prevention methods cannot meet the sand prevention and cementing needs in the long-term exploitation of other unconventional energy sources such as oil and gas reservoirs with weakly cemented reservoirs.

[0004] Therefore, how to provide a cementing and sand control completion method based on weakly cemented oil and gas reservoirs, and provide an adaptive sand control screen suitable for weakly cemented reservoir oil and gas wells are technical problems that technical personnel in this field urgently need to solve. Summary of the invention

[0005] In order to solve the above technical problems, the present invention proposes an adaptive sand control screen for weakly cemented reservoir oil and gas wells and a preparation method and application thereof.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] An adaptive sand control screen pipe for weakly cemented reservoir oil and gas wells comprises, from inside to outside, an electric heating base pipe, an adaptive high molecular polymer layer and a protective coating layer.

[0008] Preferably, the electrically heated base pipe comprises a main body pipe and a connector, and the connector is arranged at both ends of the main body pipe; the electrically heated base pipe is connected to a drill pipe, a drill collar, a reamer, etc. through the connector; the connection mode of the connection includes but is not limited to a plug-in type or a threaded type.

[0009] The main body tube includes a high-strength inner layer, a high-conductivity and heat-conductivity middle layer, and an outer layer of high thermal conductivity material from the inside to the outside; wherein the outer layer of high thermal conductivity material is a metal composite material, which is a good conductor of heat, has high temperature resistance and high corrosion resistance, and has an inert surface and does not react with the adaptive high molecular polymer in the present invention.

[0010] The inner wall of the middle interlayer includes a heating wire, which can receive an electrical signal and convert it into a thermal signal, thereby playing a heating role.

[0011] More preferably, the high thermal conductivity material includes but is not limited to low carbon steel, copper alloy, aluminum alloy and metal composite conductive material made of low carbon steel and other high conductive materials, which has good electrical and thermal conductivity and a compressive strength of more than 10 MPa.

[0012] The electric heating base pipe can be a closed pipe body or a slotted screen pipe, including one or a combination of circular holes, axial slots and circumferential slots, and a self-adaptive high molecular polymer layer to form a double sand barrier.

[0013] Preferably, the adaptive high molecular polymer is formed by curing an adaptive high molecular polymer slurry at a high temperature above 80°C;

[0014] The self-adaptive high molecular polymer slurry comprises the following raw materials in parts by weight: 17.6-37.8 parts of polyisocyanate, 20.0-30.0 parts of polyester polyol, 2.9-9.5 parts of crosslinking chain extender, 103.5-198.6 parts of pore former, 0-2.8 parts of surfactant and 30-60 parts of slurry solvent.

[0015] Beneficial effects: The adaptive high molecular polymer in the present invention has good thermodynamic properties and porous structure. It can be significantly compressed and fixed at high temperature, and respond to thermal stimulation of a certain temperature underground and expand, and can adapt to the wellbore diameter. The pore size can meet the control requirements of the formation sand particle size in the completion sand control.

[0016] Preferably, the polyisocyanate is one or a mixture of any of toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymethylene polyphenyl isocyanate (PAPI), and dimers, trimers and mixed polymers modified with polymethylene polyphenyl isocyanate as the matrix.

[0017] Preferably, the polyester polyol includes polycaprolactone diol (PCL) and / or polycarbonate diol (PCDL) with a molecular weight of 1000-3000.

[0018] Preferably, the cross-linking chain extender comprises one or a mixture of any of hydroxyl compounds, amine compounds and carboxylic acid compounds;

[0019] The hydroxy compound includes one of 1,4-butanediol, glycerol, and ethylene glycol, or a mixture of any of them;

[0020] The amine compound includes one of MOCA, TDA, trimethylethylenediamine or a mixture of any of them;

[0021] The carboxylic acid compound includes one of oxalic acid, succinic acid and terephthalic acid or a mixture of any of them.

[0022] Preferably, the pore-forming agent includes pore-forming agent A and / or pore-forming agent B;

[0023] The mass ratio of the pore former A to the pore former B is (0.2-0.5):(103.3-198.1).

[0024] The pore-forming agent A includes one or more of water, liquid carbon dioxide, dichloromethane, and cyclopentane;

[0025] The pore-forming agent B includes one of calcium oxide particles, urea particles, and solid paraffin particles, or a mixture of any of the above.

[0026] More preferably, the pore-forming agent is pore-forming agent A.

[0027] Preferably, the surfactant includes a foam stabilizer and / or a foam cell opener;

[0028] The foam stabilizer includes one of AK9905, BF2270, B8629, DC198 or a mixture of any of them;

[0029] The foam cell opener includes one of AK8805, Ortegol 500, Voranol CP1421, H-4002, Niax L-6164 or a mixture of any of them.

[0030] Preferably, the slurry solvent includes one or a combination of ethyl acetate, toluene and dimethylformamide.

[0031] Preferably, the protective coating layer is an organic polymer solid coating.

[0032] Beneficial effects: The organic polymer coating can be evenly dispersed on the surface of the adaptive polymer to protect it from being hydrolyzed. At the same time, when the adaptive sand control screen is lowered into the bottom of the well, the adaptive polymer is protected from being damaged by the well wall.

[0033] A method for preparing an adaptive sand control screen for a weakly cemented reservoir oil and gas well comprises the following steps:

[0034] The electric heating base pipe is sleeved in a thin-walled plastic pipe, and an adaptive high molecular polymer slurry is injected into the gap between the electric heating base pipe and the thin-walled plastic pipe. After the adaptive high molecular polymer slurry is solidified, a protective coating is evenly attached to the outer surface of the solidified adaptive high molecular polymer to obtain the adaptive sand control screen pipe.

[0035] More preferably, the method for injecting the adaptive polymer slurry specifically includes the following steps: first, polyester polyol, cross-linking chain extender, pore-forming agent, surfactant and slurry solvent are mixed evenly to obtain an adaptive polymer slurry pre-liquid, and the mixture is continuously stirred at a high temperature above 80°C for standby use, and then polyisocyanate is quickly injected into the adaptive polymer slurry pre-liquid, and the adaptive polymer slurry is obtained after high-speed stirring. The adaptive polymer slurry is quickly transferred and injected into the annular space between the electric heating base tube and the tetrafluoroplastic tube, and cured at 80-100°C for 8-10h.

[0036] More preferably, the protective coating layer forming method includes casting forming, spraying forming, reaction injection forming and plate continuous forming.

[0037] It should be noted that the diameter of the thin-walled plastic tube is larger than that of the electric heating base tube, and it only plays a role in assisting the solidification and molding of the adaptive polymer slurry. The inner diameter of the PTFE tube can be selected by flexibly controlling the high-temperature expansion of the adaptive polymer according to the actual wellbore diameter in the weakly cemented reservoir oil and gas production project. After the adaptive polymer slurry is solidified, the thin-walled plastic tube is removed, and then the protective coating is evenly sprayed on the outer surface of the solidified adaptive polymer.

[0038] An application of an adaptive sand control screen pipe for a weakly cemented reservoir oil and gas well in a weakly cemented reservoir comprises the following steps:

[0039] The adaptive sand control screen is compressed at high temperature, connected to the drilling tool and transmitted to the bottom of the well, and then an electrical signal is used to expand the electrically heated base pipe to fit the well wall, thus completing the engineering application of the adaptive sand control screen in the sand control process of weakly cemented reservoir oil and gas wells.

[0040] More preferably, after the adaptive polymer completely fills the wellbore annulus, the electrical signal on the well should be removed, and the thermal stimulation of the electrically heated base pipe on the adaptive polymer disappears, which can effectively prevent the mechanical properties of the electrically heated base pipe from being reduced due to continuous high temperature.

[0041] Preferably, the weakly cemented reservoir includes one of shallow gas such as mud-cemented silt sand, unconsolidated mud-silt sand, coalbed methane, and natural gas hydrate.

[0042] Compared with the prior art, the present invention has the following advantages and technical effects:

[0043] The present invention solves the problems of wellbore blockage and near-wellbore formation collapse that exist in existing sand control methods applied to weakly cemented oil and gas reservoirs such as muddy silt sand, and improves the existing organic high molecular polymer materials that are not suitable for long-term sand control in unconventional oil and gas reservoirs. The adaptive sand control screen for weakly cemented reservoir oil and gas wells in working state in the present invention can meet the control requirements of formation sand particle size in sand control in oil and gas resource exploitation on the one hand, and can adapt to wellbore diameters of various specifications on the other hand, fully fit the well wall and provide a certain support to the well wall. The demand for "wall protection and sand control" in weakly cemented reservoir oil and gas exploitation can be met. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0045] Figure 1 This is a schematic structural diagram of the adaptive sand control screen obtained in Example 15 of the present invention;

[0046] Figure 2 This is a schematic structural diagram of the adaptive sand control screen obtained in Example 15 of the present invention;

[0047] Figure 3 This is a schematic diagram of the structure of the adaptive sand control screen obtained in Example 15 of the present invention when it is lowered into the bottom of the well;

[0048] Figure 4 This is a schematic structural diagram of the adaptive sand control screen obtained in Example 15 of the present invention during normal operation;

[0049] The numbers therein are: connector 1, protective coating 2, adaptive polymer layer 3, electric heating base pipe 4, middle interlayer and inner layer 5, middle interlayer 6, outer layer of high thermal conductivity material 7, production casing 8, extraction pipe 9, compressed adaptive polymer layer 10, electric heating base pipe with slits 11, adaptive polymer in working state 12, adaptive sand control screen 13. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0052] The sources of raw materials used in the embodiments of the present invention include:

[0053] Foam cell opener AK8805 is produced by Jiangsu Meside Chemical Co., Ltd.;

[0054] Foam stabilizer AK9905 was produced by Jiangsu Meside Chemical Co., Ltd.;

[0055] Methylene diphenyl diisocyanate (MDI), Jining Zhongjian Chemical Co., Ltd., model 100ll;

[0056] Polycarbonate diol (PCDL), Jining Zhongjian Chemical Co., Ltd., molecular weight 1000;

[0057] 1,4-Butanediol, Xilong Scientific Co., Ltd., model: BDO;

[0058] The solvent of the adaptive polymer slurry pre-liquid was ethyl acetate, which was purchased from Xilong Science Co., Ltd.;

[0059] The pore-forming agent B-1 is commercially available calcium oxide particles with a particle size of 300 μm;

[0060] The pore-forming agent B-2 is commercially available calcium oxide particles with a particle size of 100 μm;

[0061] The pore-forming agent B-3 is commercially available polyethylene wax solid particles with a particle size of 100 um.

[0062] The main body tube of the electric heating base tube in the embodiment of the present invention is a commercially available electric heating tube.

[0063] Example 1

[0064] An adaptive high molecular polymer, the preparation method of which comprises the following steps:

[0065] 25g of polycarbonate diol (PCDL) softened at 80°C was stirred and mixed with 8.63g of 1,4-butanediol (BDO), 0.5g of pore former A (distilled water), 0.6g of foam opener AK8805 and 0.3g of foam stabilizer AK9905 at a high mechanical speed of a variable frequency high-speed stirrer without adding solvent to obtain an adaptive polymer slurry pre-liquid. 34.8g of diphenylmethane diisocyanate (MDI) was weighed and added to the adaptive polymer slurry pre-liquid. After high-speed stirring, an adaptive polymer slurry was obtained, which was then cured at 80°C for 8h to obtain an adaptive polymer.

[0066] The glass transition temperature of the adaptive high molecular polymer obtained in this embodiment is 59.8° C. It has a good pore structure, and the pore size distribution is between 0.07-372 μm, of which 1.61 μm accounts for the largest proportion, reaching more than 10.2%. It can adapt to the sand control accuracy of most oil and gas wells.

[0067] The adaptive polymer obtained in this embodiment has good adaptive properties. Above the glass transition temperature, the radial deformation of the adaptive polymer is limited, and an external axial force is applied to compress the adaptive polymer to a position of 40% of the height, and the axial force is maintained until the sample cools. Then, a temperature stimulus above the glass transition temperature is applied to the compressed adaptive polymer. It is found that the adaptive expansion rate of the adaptive polymer in this embodiment is 100%, and the adaptive expansion time is less than 30 minutes at 120°C.

[0068] By applying axial limiting, samples of the adaptive polymer obtained by the embodiment formula in two different states of adaptive expansion 80%L and adaptive expansion 100%L were obtained, and their permeability characteristics were measured. The permeability test method refers to the GB / T 34533-2017 standard, and it is finally found that the permeability of the adaptive polymer with adaptive expansion of 80%L is lower than 8.37D without adaptive compression, but can still reach 5.88D, indicating that the adaptive polymer in this state still has good permeability characteristics. In the state of adaptive expansion of 100%L, the permeability is as high as 10.44D, which is higher than the expansion rate before adaptive compression.

[0069] Example 2

[0070] An adaptive high molecular polymer, which is different from Example 1 in that its raw materials include: 25g polycaprolactone diol, 9.51g 1,4-butanediol, 0.2g 0.5g pore former A (distilled water), 0.75g foam opening agent AK8805, 2g foam stabilizer AK9905 and 36.92g diphenylmethane diisocyanate (MDI), and no solvent is added. Other process steps and parameters are the same as those in Example 1.

[0071] The performance testing method is the same as that in Example 1. In the hydrate mining process of this embodiment, the permeability of the adaptive high molecular polymer can reach 4.44D, the compressive strength is 0.95MPa, and the adaptive expansion rate can reach 97.4%.

[0072] Example 3

[0073] An adaptive high molecular polymer, which is different from Example 1 in that the mass ratio of polyisocyanate (methylene diphenyl diisocyanate (MDI)), polyester polyol (polycarbonate diol (PCDL)), cross-linking chain extender (1,4-butanediol), and solvent (ethyl acetate) is 18:25:3:20, and no surfactant is added;

[0074] The mass ratio of polyester polyol to pore former B-1 is 1:4.3;

[0075] During the curing process of the adaptive polymer slurry, a vacuum drying oven was used with a constant temperature of 80°C and a curing time of 10 h;

[0076] The other process steps and parameters are the same as those in Example 1.

[0077] Example 4

[0078] An adaptive high molecular polymer, which is different from Example 1 in that the mass ratio of polyisocyanate (methylene diphenyl diisocyanate (MDI)), polyester polyol (polycarbonate diol (PCDL)), cross-linking chain extender (1,4-butanediol), and solvent (ethyl acetate) is 18:25:3:25, and no surfactant is added;

[0079] The mass ratio of polyester polyol to pore former B-1 is 1:6.4;

[0080] During the curing process of the adaptive polymer slurry, a vacuum drying oven was used with a constant temperature of 80°C and a curing time of 10 h;

[0081] The other process steps and parameters are the same as those in Example 1.

[0082] Example 5

[0083] An adaptive high molecular polymer, which is different from Example 1 in that the mass ratio of polyisocyanate (methylene diphenyl diisocyanate (MDI)), polyester polyol (polycarbonate diol (PCDL)), cross-linking chain extender (1,4-butanediol), and solvent (ethyl acetate) is 18:25:3:43, and no surfactant is added;

[0084] The mass ratio of polyester polyol to pore former B-1 and pore former B-2 is 1:3.4:1.7;

[0085] During the curing process of the adaptive polymer slurry, a vacuum drying oven was used with a constant temperature of 80°C and a curing time of 10 h;

[0086] The other process steps and parameters are the same as those in Example 1.

[0087] Example 6

[0088] An adaptive high molecular polymer, which is different from Example 1 in that the mass ratio of polyisocyanate (methylene diphenyl diisocyanate (MDI)), polyester polyol (polycarbonate diol (PCDL)), cross-linking chain extender (1,4-butanediol), and solvent (liquid paraffin) is 18:25:3:60, and no surfactant is added;

[0089] The mass ratio of polyester polyol to pore former B-1 and pore former B-2 is 1:4:0.8;

[0090] During the curing process of the adaptive polymer slurry, a vacuum drying oven was used with a constant temperature of 80°C and a curing time of 10 h;

[0091] The other process steps and parameters are the same as those in Example 1.

[0092] Example 7

[0093] An adaptive high molecular polymer, which is different from Example 1 in that the mass ratio of polyisocyanate (methylene diphenyl diisocyanate (MDI)), polyester polyol (polycarbonate diol (PCDL)), cross-linking chain extender (1,4-butanediol), and solvent (ethyl acetate) is 18:25:3:80, and no surfactant is added;

[0094] The mass ratio of polyester polyol to pore former B-1 and pore former B-3 is 1:4.8:2.4;

[0095] During the curing process of the adaptive polymer slurry, a vacuum drying oven was used with a constant temperature of 80°C and a curing time of 10 h;

[0096] The other process steps and parameters are the same as those in Example 1.

[0097] Example 8

[0098] An adaptive high molecular polymer, which is different from Example 1 in that the mass ratio of polyisocyanate (methylene diphenyl diisocyanate (MDI)), polyester polyol (polycarbonate diol (PCDL)), cross-linking chain extender (1,4-butanediol), and solvent (ethyl acetate) is 5:5:1:20, and no surfactant is added;

[0099] The mass ratio of polyester polyol to pore former B-1 and pore former B-3 is 1:5.8:3;

[0100] During the curing process of the adaptive polymer slurry, a vacuum drying oven was used with a constant temperature of 80°C and a curing time of 10 h;

[0101] The other process steps and parameters are the same as those in Example 1.

[0102] Example 9

[0103] An adaptive high molecular polymer, which is different from Example 1 in that the mass ratio of polyisocyanate (methylene diphenyl diisocyanate (MDI)), polyester polyol (polycarbonate diol (PCDL)), cross-linking chain extender (1,4-butanediol), and solvent (ethyl acetate) is 38:25:9:120, and no surfactant is added;

[0104] The mass ratio of polyester polyol to pore former B-1 and pore former B-3 is 1:7.4:3.8;

[0105] During the curing process of the adaptive polymer slurry, a vacuum drying oven was used with a constant temperature of 80°C and a curing time of 10 h;

[0106] The other process steps and parameters are the same as those in Example 1.

[0107] Example 10

[0108] An adaptive high molecular polymer, which is different from Example 1 in that the mass ratio of polyisocyanate (methylene diphenyl diisocyanate (MDI)), polyester polyol (polycarbonate diol (PCDL)), cross-linking chain extender (1,4-butanediol), and solvent (ethyl acetate) is 38:25:9:60, and no surfactant is added;

[0109] The mass ratio of polyester polyol to pore former B-1 and pore former B-3 is 1:5:1.2;

[0110] During the curing process of the adaptive polymer slurry, a vacuum drying oven was used with a constant temperature of 80°C and a curing time of 10 h;

[0111] The other process steps and parameters are the same as those in Example 1.

[0112] Embodiment 11

[0113] An adaptive high molecular polymer, which is different from Example 1 in that the mass ratio of polyisocyanate (methylene diphenyl diisocyanate (MDI)), polyester polyol (polycarbonate diol (PCDL)), cross-linking chain extender (1,4-butanediol), and solvent (ethyl acetate) is 38:25:9:60, and no surfactant is added;

[0114] The mass ratio of polyester polyol to pore former B-1 and pore former B-3 is 1:5.4:1.1;

[0115] During the curing process of the adaptive polymer slurry, a vacuum drying oven was used with a constant temperature of 80°C and a curing time of 10 h;

[0116] The other process steps and parameters are the same as those in Example 1.

[0117] Example 12

[0118] An adaptive high molecular polymer, which is different from Example 1 in that the mass ratio of polyisocyanate (methylene diphenyl diisocyanate (MDI)), polyester polyol (polycarbonate diol (PCDL)), cross-linking chain extender (1,4-butanediol), and solvent (ethyl acetate) is 38:25:9:60, and no surfactant is added;

[0119] The mass ratio of polyester polyol to pore former B-1 and pore former B-3 is 1:5.8:1;

[0120] During the curing process of the adaptive polymer slurry, a vacuum drying oven was used with a constant temperature of 80°C and a curing time of 10 h;

[0121] The other process steps and parameters are the same as those in Example 1.

[0122] Embodiment 13

[0123] An adaptive high molecular polymer, which is different from Example 1 in that the mass ratio of polyisocyanate (methylene diphenyl diisocyanate (MDI)), polyester polyol (polycarbonate diol (PCDL)), cross-linking chain extender (1,4-butanediol), and solvent (ethyl acetate) is 38:25:9:60, and no surfactant is added;

[0124] The mass ratio of polyester polyol to pore former B-1 and pore former B-3 is 1:6:0.9;

[0125] During the curing process of the adaptive polymer slurry, a vacuum drying oven was used with a constant temperature of 80°C and a curing time of 10 h;

[0126] The other process steps and parameters are the same as those in Example 1.

[0127] Embodiment 14

[0128] An adaptive high molecular polymer, which is different from Example 1 in that the mass ratio of polyisocyanate (methylene diphenyl diisocyanate (MDI)), polyester polyol (polycarbonate diol (PCDL)), cross-linking chain extender (1,4-butanediol), and solvent (ethyl acetate) is 38:25:9:60, and no surfactant is added;

[0129] The mass ratio of polyester polyol to pore former B-1 and pore former B-3 is 1:6.2:0.8;

[0130] During the curing process of the adaptive polymer slurry, a vacuum drying oven was used with a constant temperature of 80°C and a curing time of 10 h;

[0131] The other process steps and parameters are the same as those in Example 1.

[0132] Technical effects:

[0133] The permeability, compressive strength and adaptive expansion rate of the adaptive high molecular polymer obtained in Examples 3-14 were measured, and the test results are shown in Table 1. The permeability test method refers to the GB / T 34533-2017 standard, the compressive strength test method refers to the GB50107-2010 standard, and the adaptive expansion rate test method refers to the test method in Example 1.

[0134] Table 1

[0135]

[0136]

[0137] As can be seen from Table 2, the adaptive polymers obtained in Examples 3-4, 5-6 and 7-14 have high mechanical strength and permeability under different types of pore-forming agent ratios. In Examples 3-14, due to the different types and mass percentages of the pore-forming agents, the mass percentages of the solvents added to the adaptive polymer pre-liquid are also different. In Examples 10-12, the pore-forming agent combination of the adaptive polymer is a mixture of pore-forming agent B-1 and pore-forming agent B-3, and the obtained adaptive polymer has a high permeability, up to 13.4D. In Examples 13-14, the pore-forming agent combination of the adaptive polymer is a compound of pore-forming agent B-1 and pore-forming agent B-3, and the obtained adaptive polymer has a high compressive strength, fluctuating around 4.5MPa.

[0138] Embodiment 15

[0139] A method for preparing an adaptive sand control screen for a weakly cemented reservoir oil and gas well, wherein an adaptive high molecular polymer is prepared according to the raw material ratios in Examples 1-14, comprising the following steps:

[0140] (1) Weighing polyester polyol, cross-linking chain extender and other pore-forming agents and surfactants added in a certain proportion to obtain an adaptive polymer slurry pre-liquid, stirring continuously at a high temperature above 80° C. or standing still for standby, waiting for the injection of polyisocyanate.

[0141] (2) Prepare polytetrafluoroethylene thin-walled plastic tubes of different inner diameters at the same height as the electrically heated base tube. The inner diameter of the polytetrafluoroethylene thin-walled plastic tube should be significantly larger than the outer diameter of the base tube. Rapidly inject polyisocyanate into the adaptive polymer slurry precursor obtained in step (1), and after high-speed stirring, quickly transfer the polymer slurry to the annular space between the electrically heated base tube and the polytetrafluoroethylene plastic tube, and maintain the temperature at 80-100°C for more than 8 hours of curing. After the adaptive polymer slurry is cured, remove the polytetrafluoroethylene thin-walled plastic tube, and evenly spray an outer layer of protective coating on the outer surface of the adaptive polymer to obtain an adaptive sand control screen for weakly bonded reservoir oil and gas wells.

[0142] like Figure 1-2 As shown, the structure of an adaptive sand control screen pipe for weakly cemented reservoir oil and gas wells is as follows: from the inside to the outside, it includes: an electric heating base pipe 4, an adaptive high molecular polymer layer 3 and a protective coating layer 2.

[0143] The electric heating base pipe comprises a main body pipe and a connector 1, wherein the connector is arranged at both ends of the main body pipe; the electric heating base pipe is connected to a drill pipe, a drill collar, a reamer, etc. through the connector; the connection mode of the connection includes but is not limited to a plug-in type or a threaded type.

[0144] The main body tube includes an inner layer and a middle interlayer 5, and an outer layer 7 of a high thermal conductivity material from the inside to the outside; wherein the outer layer of the high thermal conductivity material is a metal composite material, which is a good conductor of heat, has high temperature resistance and high corrosion resistance, and has an inert surface and does not react with the adaptive high molecular polymer in the present invention.

[0145] The inner wall of the middle interlayer includes a heating wire, which can receive an electrical signal and convert it into a thermal signal, thereby playing a heating role.

[0146] Example 16

[0147] like Figure 3-4 As shown, an application of an adaptive sand control screen for weakly cemented reservoir oil and gas wells, using the adaptive sand control screen obtained in Example 15 for weakly cemented reservoir oil and gas wells, can be applied to weakly cemented reservoirs such as shallow gas, coalbed methane, and natural gas hydrates, etc. The specific application method includes the following steps:

[0148] (1) In a radial compressor, a high temperature confining pressure is applied to radially compress the outer layer of the adaptive sand control screen electrically heated base pipe and the outer protective coating without axial deformation;

[0149] The ambient temperature of the environment in which the confining pressure is applied is higher than the glass transition temperature of the adaptive polymer by more than 20° C. The confining pressure is applied by liquid or gas, and the compression amount of the adaptive polymer in the radial compressor is changed by adjusting the size of the confining pressure.

[0150] (2) The compressed adaptive sand control screen pipe of the weakly cemented reservoir oil and gas well is connected to the drill bit through the upper and lower connectors of the electric heating base pipe and then lowered into the bottom of the well. Electrical stimulation is applied on the well and transmitted to the electric heating base pipe through the drill pipe. The electric heating base pipe senses the electrical signal and converts it into a thermal signal. The compressed adaptive high molecular polymer expands after sensing the thermal stimulation and can completely fit the well wall, forming a porous seepage channel and playing a certain supporting role on the well wall. In other words, the engineering application of the adaptive sand control screen pipe in the sand control process of weakly cemented reservoir oil and gas wells is completed.

[0151] Among them, after the adaptive polymer completely fills the wellbore annulus, the electrical signal on the well should be removed, and the thermal stimulation of the electric heating base pipe to the adaptive polymer will disappear, which can effectively prevent the reduction of the mechanical properties of the electric heating base pipe caused by continuous high temperature.

[0152] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An adaptive sand control screen for weakly cemented reservoir oil and gas wells, characterized in that: From the inside to the outside, it includes: an electric heating base tube, an adaptive high molecular polymer layer and a protective coating layer.

2. The adaptive sand control screen for weakly cemented reservoir oil and gas wells according to claim 1, characterized in that: The electric heating base tube comprises a main body tube and a connector, wherein the connector is arranged at both ends of the main body tube; The main body tube comprises an inner layer, a middle interlayer and an outer layer of a material with a high thermal conductivity coefficient from the inside to the outside; The inner wall of the middle interlayer includes a heating wire.

3. The adaptive sand control screen for weakly cemented reservoir oil and gas wells according to claim 1, characterized in that: The self-adaptive high molecular polymer is formed by curing the self-adaptive high molecular polymer slurry at a high temperature of 80 to 120°C; The self-adaptive high molecular polymer slurry comprises the following raw materials in parts by weight: 17.6-37.8 parts of polyisocyanate, 20.0-30.0 parts of polyester polyol, 2.9-9.5 parts of crosslinking chain extender, 0.2-198.6 parts of pore former, 0-2.8 parts of surfactant and 30-60 parts of slurry solvent.

4. The adaptive sand control screen for weakly cemented reservoir oil and gas wells according to claim 3, characterized in that: The polyisocyanate is one of toluene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate, and dimers, trimers and mixed polymers modified with polymethylene polyphenyl isocyanate as a matrix, or a mixture of any of the above.

5. The adaptive sand control screen for weakly cemented reservoir oil and gas wells according to claim 3, characterized in that: The polyester polyol includes polycaprolactone diol and / or polycarbonate diol, and has a molecular weight of 1000-3000.

6. The adaptive sand control screen for weakly cemented reservoir oil and gas wells according to claim 3, characterized in that: The cross-linking chain extender includes one or a mixture of any of hydroxyl compounds, amine compounds and carboxylic acid compounds; The hydroxy compound includes one of 1,4-butanediol, glycerol, and ethylene glycol, or a mixture of any of them; The amine compound includes one of MOCA, TDA, trimethylethylenediamine or a mixture of any of them; The carboxylic acid compound includes one of oxalic acid, succinic acid and terephthalic acid or a mixture of any of them.

7. The adaptive sand control screen for weakly cemented reservoir oil and gas wells according to claim 1, characterized in that: The protective coating layer is an organic polymer solid coating.

8. A method for preparing an adaptive sand control screen for a weakly cemented reservoir oil and gas well according to any one of claims 1 to 7, characterized in that: The following steps are involved: The electric heating base pipe is sleeved in a thin-walled plastic pipe, and an adaptive high molecular polymer slurry is injected into the gap between the electric heating base pipe and the thin-walled plastic pipe. After the adaptive high molecular polymer slurry is solidified, a protective coating is evenly attached to the outer surface of the solidified adaptive high molecular polymer to obtain the adaptive sand control screen pipe.

9. The use of the adaptive sand control screen for weakly cemented reservoir oil and gas wells according to any one of claims 1 to 7 in weakly cemented reservoirs, characterized in that: The following steps are involved: The adaptive sand control screen is compressed at high temperature, connected to the drilling tool and transmitted to the bottom of the well, and then an electrical signal is used to expand the electrically heated base pipe to fit the well wall, thus completing the engineering application of the adaptive sand control screen in the sand control process of weakly cemented reservoir oil and gas wells.

10. The use according to claim 9, characterized in that: The weakly cemented reservoir includes one of shallow gas, coalbed methane, and natural gas hydrate, such as mud-cemented fine sand, unconsolidated muddy fine sand, etc.

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