High-temperature-resistant submersible cable and preparation method thereof

Abstract

The invention relates to a high-temperature-resistant submersible cable and a preparation method thereof. According to the technical scheme, a sintered polyimide inner insulating layer is wrapped outside a copper conductor, a modified high-temperature-resistant nylon outer insulating layer is extruded outside the copper conductor, the polyimide inner insulating layer is tightly wrapped, and an inorganic heat-insulating woven cushion layer is woven outside the modified high-temperature-resistant nylon outer insulating layer. The nickel-based alloy steel pipe packaging sheath layer is packaged outside the inorganic substance heat insulation woven cushion layer; and the modified high-temperature-resistant nylon material is extruded outside the nickel-based alloy steel pipe packaging sheath layer to form an integrated high-temperature-resistant nylon anticorrosive layer, and the nickel-based alloy steel belt armor layer is mounted on the outer side of the integrated high-temperature-resistant nylon anticorrosive layer. The invention has the following beneficial effects: the adopted modified high-temperature-resistant nylon material can normally work at a static high temperature of 370 DEG C, the adopted nickel-based alloy pressure-resistant steel pipe can resist a high pressure of more than 50Mpa and has a good sealing-level anti-corrosion effect, and the electric energy supply of the submersible unit in a high-temperature, high-pressure and high-corrosion underground environment is fully ensured.

Description

Technical Field

[0001] The invention relates to the technical field of power cables for high-temperature electric submersible pump oil production systems, and in particular to a high-temperature resistant submersible oil cable and a preparation method thereof. Background Art

[0002] At present, the working environment of high-temperature oil wells is generally harsh. The temperature is very high, and the heavy oil has high viscosity, sulfur content, and strong acidity. In the production of such downhole conditions, general insulating materials are difficult to work for a long time under high temperature conditions above 300°C. Moreover, as mixed liquids such as strong acids and alkalis, high-concentration hydrogen sulfide, etc. penetrate into the interior of the cable under high pressure, the cable protective layer suffers serious corrosion, which directly affects the life of the cable. In addition, there are many difficulties and problems such as the prominent contradiction between safety and economy, complex operating conditions and downhole conditions, and high performance requirements for completion equipment and tooling. Summary of the invention

[0003] The purpose of the present invention is to provide a high-temperature resistant submersible cable and a preparation method thereof in view of the above-mentioned defects in the prior art, which can withstand high temperatures of 370°C, high pressures of more than 50Mpa and corrosion-resistant harsh underground environments.

[0004] The present invention provides a high-temperature resistant submersible cable, the technical solution of which is as follows: comprising a copper conductor (1), a polyimide inner insulation layer (2), and a nickel-based alloy steel belt armor layer (7), wherein the copper conductor (1) is externally wrapped with a sintered polyimide inner insulation layer (2), wherein the polyimide inner insulation layer (2) is externally extruded with a modified high-temperature resistant nylon outer insulation layer (3), and the polyimide inner insulation layer (2) is tightly wrapped, an inorganic heat-insulating braided cushion layer (4) is woven on the outside of the modified high-temperature resistant nylon outer insulation layer (3), and a nickel-based alloy steel tube encapsulated sheath layer (5) is encapsulated on the outside of the inorganic heat-insulating braided cushion layer (4); a modified high-temperature resistant nylon material is extruded on the outside of the nickel-based alloy steel tube encapsulated sheath layer (5) to form an integrated high-temperature resistant nylon anti-corrosion layer (6), and a nickel-based alloy steel belt armor layer (7) is installed on the outside of the integrated high-temperature resistant nylon anti-corrosion layer (6).

[0005] Preferably, the preparation method of the modified high temperature resistant nylon material is as follows: according to the mass proportion, 70%-75% nylon resin, 15%-20% glass fiber, 2%-5% titanium dioxide powder, 1%-2% rare earth, and 2%-8% silicate are heated at 260℃-300℃ and mechanically stirred to fully blend. Then, the modified mixed high-temperature resistant nylon resin is obtained by dispersion polymerization, condensation, washing, and drying methods, and then 2-3mm modified high-temperature resistant nylon material particles are made through granulation equipment.

[0006] Preferably, the inorganic thermal insulation woven mat layer (4) is made of one or more of mica fiber, quartz fiber, glass fiber and ceramic fiber.

[0007] Preferably, the above-mentioned nickel-based alloy steel pipe packaging material includes but is not limited to incoloy825, Alloy625, duplex stainless steel 2205 and duplex stainless steel 2507.

[0008] Preferably, the modified high-temperature resistant nylon material is extruded onto the outside of the nickel-based alloy steel pipe encapsulation sheath layer (5) through an extrusion die to form an integrated high-temperature resistant nylon anti-corrosion layer (6).

[0009] Preferably, the extrusion die is composed of a die core (6.1) and a die sleeve (6.2); the die core (6.1) is inserted into the inner side of the die sleeve (6.2); the die core (6.1) is configured as a duckbill structure; a wire hole (6.1.1) is provided in the end of the duckbill structure; and a guide groove (6.1.2) is provided between the wire holes (6.1.1); the die sleeve (6.2) is configured as a cylindrical structure; the internal flow channel (6.2.1) on one side is in a bell-mouth shape; and the end molding area (6.2.2) on the other side is a flat hole structure.

[0010] Preferably, the wire-passing holes (6.1.1) are provided with three groups, and the three nickel-based alloy steel tube encapsulating sheath layers (5) are inserted into the mold core (6.1) and pass through the wire-passing holes (6.1.1). At the same time, the high-temperature resistant nylon material flows through the gap formed by the guide groove (6.1.2) and the internal flow channel (6.2.1), and is extruded and wrapped on the outside of the three nickel-based alloy steel tube encapsulating sheath layers (5), and comes out from the end molding area (6.2.2) together, and then is molded by cooling water to form an integrated high-temperature resistant nylon anti-corrosion layer (6).

[0011] Preferably, the copper conductor (1) is extruded into a round copper conductor by a copper extruder, the copper conductor (1) is nickel-plated on the outside to prevent oxidation of the copper conductor, and the diameter of the copper conductor (1) is 3.0 mm to 7.0 mm; the thickness of the polyimide inner insulation layer (2) is 0.3 mm to 0.8 mm; the thickness of the modified high-temperature resistant nylon outer insulation layer (3) is 0.5 mm to 1.2 mm; the thickness of the inorganic heat-insulating braided cushion layer (4) is 0.3 mm to 1.0 mm; the thickness of the nickel-based alloy steel tube encapsulation sheath layer (5) is 0.7 mm to 1.5 mm; the thickness of the integrated high-temperature resistant nylon anti-corrosion layer (6) is 1.0 mm to 2.0 mm; and the thickness of the nickel-based alloy steel belt armor layer (7) is 0.3 mm to 0.5 mm.

[0012] The preparation method of the high temperature resistant submersible oil cable mentioned in the present invention comprises the following steps: Step 1, extruding a copper wire blank into a round copper conductor, the outer surface of the copper conductor (1) is nickel-plated to prevent oxidation of the copper conductor, and the diameter of the copper conductor (1) is 3.0 mm to 7.0 mm; Step 2: On the outside of the circular copper conductor (1), a polyimide insulating granular material is extruded onto the outside of the copper conductor (1) using a twin-screw extruder that can be heated to 500° C. to form a polyimide inner insulating layer (2); Step 3: On the outside of the polyimide inner insulation layer (2), a modified high-temperature resistant nylon material is tightly extruded on the outside of the polyimide inner insulation layer to form a modified high-temperature resistant nylon outer insulation layer (3); Step 4: one or more of mica fiber, quartz fiber, glass fiber and ceramic fiber made of inorganic material is tightly woven on the outside of the modified high temperature resistant nylon outer insulation layer (3) to form an inorganic thermal insulation woven mat layer (4); Step 5, the nickel-based alloy steel strip passes through a shaping roller, and after shaping, is longitudinally wrapped around the outside of the inorganic heat-insulating woven cushion layer (4), and a laser welding method is used to form a nickel-based alloy steel tube, and then the tube is drawn and sized through a die, and tightly wrapped around the outside of the inorganic heat-insulating woven cushion layer (4), forming a sealed nickel-based alloy steel tube packaging sheath layer (5), which can withstand a pressure of more than 50 MPa and has good corrosion resistance; Step 6, using the modified high temperature resistant nylon material and using an extrusion die, the three nickel-based alloy steel tubes encapsulating sheath layers (5) are passed through the die core (6.1) and through the wire hole (6.1.1), and at the same time, the high temperature resistant nylon material flows through the gap between the guide groove (6.1.2) and the internal flow channel (6.2.1), and is extruded and wrapped around the outside of the three nickel-based alloy steel tubes encapsulating sheath layers (5), and comes out from the end molding area (6.2.2), and then is molded by cooling water to form an integrated high temperature resistant nylon anti-corrosion layer (6); Step 7: The nickel-based alloy steel strip is laminated by pressing to form an interlocking armoring layer (7) on the outside of the integrated high-temperature resistant nylon anti-corrosion layer (6) on the outside of the nickel-based alloy steel tube encapsulation sheath layer (5).

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: The modified high-temperature resistant nylon material used in the present invention can work normally at a static high temperature of 370°C, the nickel-based alloy pressure-resistant steel pipe used can withstand a high pressure of more than 50Mpa, and has a good sealing-level anti-corrosion effect; the integrated high-temperature resistant nylon anti-corrosion layer effectively isolates corrosive gas-liquid mixtures such as strong acids, alkalis, hydrogen sulfide, etc. from penetrating into the cable, and has good stability, does not chemically react with strong acids, alkalis, hydrogen sulfide, etc., and plays an anti-corrosion role; the present invention is used for production operations under high temperature, high pressure and severe corrosion conditions in the submersible electric pump oil production system, fully guarantees the power supply of the submersible unit in the high temperature, high pressure and high corrosion underground environment, reduces the economic losses caused by well lifting, well repair and equipment aging caused by high temperature, high pressure and corrosion, improves oil production efficiency, and ensures production safety and service life; in addition, the present invention has a reasonable design, compact structure, and safe and convenient operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic structural diagram of the high temperature resistant submersible oil cable of the present invention; Figure 2 This is a schematic diagram of DSC analysis comparison before and after modification of high temperature resistant nylon material; Figure 3 It is a schematic diagram of thermogravimetric analysis of modified high temperature resistant nylon material; Figure 4 It is a structural schematic diagram of a core of an extrusion die; Figure 5 It is a structural schematic diagram of a die sleeve of an extrusion die; Figure 6 It is a schematic diagram of the structure of the die core and die sleeve of the extrusion die when they are working; In the above figure: copper conductor 1, polyimide inner insulation layer 2, modified high temperature resistant nylon outer insulation layer 3, inorganic thermal insulation woven cushion layer 4, nickel-based alloy steel tube encapsulation sheath layer 5, integrated high temperature resistant nylon anti-corrosion layer 6, nickel-based alloy steel belt armor layer 7, mold core 6.1, mold sleeve 6.2, wire hole 6.1.1, guide groove 6.1.2, internal flow channel 6.2.1, end molding area 6.2.2. DETAILED DESCRIPTION

[0015] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0016] Example 1, reference Figure 1The present invention mentions a high-temperature resistant submersible cable, comprising a copper conductor 1, a polyimide inner insulation layer 2, and a nickel-based alloy steel belt armor layer 7. The copper conductor 1 is wrapped with a sintered polyimide inner insulation layer 2 on the outside, wherein the polyimide inner insulation layer 2 is extruded with a modified high-temperature resistant nylon outer insulation layer 3 on the outside, and the polyimide inner insulation layer 2 is tightly wrapped, an inorganic thermal insulation woven pad layer 4 is woven on the outside of the modified high-temperature resistant nylon outer insulation layer 3, and a nickel-based alloy steel tube encapsulated sheath layer 5 is encapsulated on the outside of the inorganic thermal insulation woven pad layer 4; the modified high-temperature resistant nylon material is extruded on the outside of the nickel-based alloy steel tube encapsulated sheath layer 5 to form an integrated high-temperature resistant nylon anti-corrosion layer 6, and a nickel-based alloy steel belt armor layer 7 is installed on the outside of the integrated high-temperature resistant nylon anti-corrosion layer 6.

[0017] The preparation method of the modified high temperature resistant nylon material is as follows: according to the mass proportion, 70%-75% nylon resin, 15%-20% glass fiber, 2%-5% titanium dioxide powder, 1%-2% rare earth, and 2%-8% silicate are heated at 260℃-300℃ and mechanically stirred to fully blend. Then, the modified mixed high-temperature resistant nylon resin is obtained by dispersion polymerization, condensation, washing, and drying methods, and then 2-3mm modified high-temperature resistant nylon material particles are made through granulation equipment.

[0018] The inorganic heat-insulating woven mat layer 4 is made of one or more of mica fiber, quartz fiber, glass fiber and ceramic fiber.

[0019] The above-mentioned nickel-based alloy steel pipe packaging materials include but are not limited to incoloy825, Alloy625, duplex stainless steel 2205 and duplex stainless steel 2507.

[0020] The modified high temperature resistant nylon material is extruded onto the outside of the nickel-based alloy steel pipe packaging sheath layer 5 through an extrusion die to form an integrated high temperature resistant nylon anti-corrosion layer 6.

[0021] Reference Figure 4-Figure 6 The extrusion die mentioned in the present invention consists of a core mold 6.1 and a sleeve mold 6.2. The core mold 6.1 is inserted into the inner side of the sleeve mold 6.2. The core mold 6.1 is configured as a duckbill structure. A wire hole 6.1.1 is provided in the end of the duckbill structure. A guide groove 6.1.2 is provided between the wire holes 6.1.1. The sleeve mold 6.2 is configured as a cylindrical structure. The internal flow channel 6.2.1 on one side is in a bell-mouth shape, and the end molding area 6.2.2 on the other side is a flat hole structure.

[0022] The above-mentioned wire-passing holes 6.1.1 are provided with three groups. Three nickel-based alloy steel tubes encapsulating sheath layers 5 penetrate into the mold core 6.1 and pass through the wire-passing holes 6.1.1. At the same time, the high-temperature resistant nylon material flows through the gap between the guide groove 6.1.2 and the internal flow channel 6.2.1, and is extruded and wrapped on the outside of the three nickel-based alloy steel tubes encapsulating sheath layers 5, and comes out from the end molding area 6.2.2 together, and then is molded by cooling water to form an integrated high-temperature resistant nylon anti-corrosion layer 6.

[0023] The above-mentioned copper conductor 1 adopts a copper extruder to extrude a copper wire blank into a round copper conductor. The outside of the copper conductor 1 is nickel-plated to prevent oxidation of the copper conductor. The diameter of the copper conductor 1 is 3.0mm~7.0mm; the thickness of the polyimide inner insulation layer 2 is 0.3mm~0.8mm; the thickness of the modified high-temperature resistant nylon outer insulation layer 3 is 0.5mm~1.2mm; the thickness of the inorganic thermal insulation woven cushion layer 4 is 0.3mm~1.0mm; the thickness of the nickel-based alloy steel pipe encapsulation sheath layer 5 is 0.7mm~1.5mm; the thickness of the integrated high-temperature resistant nylon anti-corrosion layer 6 is 1.0mm~2.0mm; the thickness of the nickel-based alloy steel belt armor layer 7 is 0.3mm~0.5mm.

[0024] The preparation method of the high temperature resistant submersible oil cable mentioned in the present invention comprises the following steps: Step 1, extruding a copper wire blank into a round copper conductor, the outer surface of the copper conductor 1 is nickel-plated to prevent oxidation of the copper conductor, and the diameter of the copper conductor 1 is 3.0 mm to 7.0 mm; Step 2: On the outside of the circular copper conductor 1, a polyimide insulating granular material is extruded on the outside of the copper conductor 1 by using a twin-screw extruder that can be heated to 500° C. to form a polyimide inner insulating layer 2; Step 3: On the outside of the polyimide inner insulating layer 2, a modified high-temperature resistant nylon material is tightly extruded on the outside of the polyimide inner insulating layer to form a modified high-temperature resistant nylon outer insulating layer 3; Step 4: one or more of mica fiber, quartz fiber, glass fiber and ceramic fiber made of inorganic materials are tightly woven on the outside of the modified high temperature resistant nylon outer insulation layer 3 to form an inorganic heat insulation woven mat layer 4; Step 5, the nickel-based alloy steel strip passes through a shaping roller, and after shaping, is longitudinally wrapped on the outside of the inorganic heat-insulating woven cushion layer 4, and a laser welding method is used to form a nickel-based alloy steel pipe, and then drawn and sized through a die, and tightly wrapped on the outside of the inorganic heat-insulating woven cushion layer 4 to form a sealed nickel-based alloy steel pipe packaging sheath layer 5, which can withstand a pressure of more than 50Mpa and has good corrosion resistance; Step 6, using an extrusion die from a modified high temperature resistant nylon material, three nickel-based alloy steel tubes encapsulating sheath layers 5 pass through the mold core 6.1 and through the wire hole 6.1.1, and at the same time, the high temperature resistant nylon material flows through the gap between the guide groove 6.1.2 and the internal flow channel 6.2.1, and is extruded and wrapped around the outside of the three nickel-based alloy steel tubes encapsulating sheath layers 5, and comes out from the end molding area 6.2.2 together, and then is molded by cooling water to form an integrated high temperature resistant nylon anti-corrosion layer 6; Step 7: The nickel-based alloy steel strip is laminated by compression molding to be armored in an interlocking manner on the outside of the integrated high-temperature resistant nylon anti-corrosion layer 6 on the outside of the nickel-based alloy steel pipe packaging sheath layer 5 to form a nickel-based alloy steel strip armor layer 7. Example 2

[0025] The present invention provides a method for manufacturing a high temperature resistant and corrosion resistant submersible oil cable, comprising the following steps: Step 1, extruding the copper wire blank into a round copper conductor 1 with a diameter of 3.6 mm, and nickel-plating the outer surface of the round copper conductor 1 to prevent oxidation of the copper conductor; Step 2: On the outside of the copper conductor 1, a polyimide inner insulating layer 2 with an insulation thickness of 0.7 mm is tightly coated on the outside of the copper conductor 1 by using a twin-screw extruder that can be heated to 500° C. from polyimide granules; Step 3, the modified high temperature resistant nylon material is tightly wrapped around the outside of the polyimide inner insulation layer 2 by extruding a tube and drawing a true hole, with an insulation thickness of 0.8 mm, to form a modified high temperature resistant nylon outer insulation layer 3; Step 4: tightly weave glass fiber filaments and ceramic fiber filaments on the outside of the modified high-temperature resistant nylon outer insulation layer 3 to form an inorganic heat-insulating woven cushion layer 4 with a thickness of 0.3 mm; Step 5: The Alloy625 nickel-based alloy steel strip with a thickness of 1.149 mm is passed through a shaping roller, longitudinally wrapped after shaping, and formed into a nickel-based alloy steel pipe by a laser welding method, and then drawn through a die to a diameter of 9.5 mm, and tightly wrapped on the outside of the inorganic thermal insulation woven cushion layer 4 to form a sealed nickel-based alloy steel pipe packaging sheath layer 5, which can withstand a pressure of more than 50 MPa; Step 6: Through a specially designed extrusion die, the high temperature resistant nylon material is continuously extruded onto the outside of the three nickel-based alloy steel pipes placed in parallel, forming an integrated high temperature resistant nylon anti-corrosion layer 6, the thickness of which is 2 mm; Step 7: The monel nickel-based alloy steel strip is pressed and stacked to be armored on the outside of the integrated high-temperature resistant nylon anti-corrosion layer 6 in an interlocking manner to form a flat nickel-based alloy steel strip armor layer 7 with a size of 13.0 mm×32.5 mm; Specifically, the preparation method of the modified high temperature resistant nylon material mentioned above is as follows: nylon resin, glass fiber, titanium dioxide powder, rare earth, and silicate are heated at 260°C, and mechanically stirred to fully fuse, and then the modified high temperature resistant mixed nylon resin is obtained by dispersion polymerization through condensation, washing, drying and other methods, and then granulated into 2-3mm particles by granulation equipment. The modified high temperature resistant nylon material, glass fiber, titanium dioxide powder, rare earth, and silicate are mixed according to the mass proportion, nylon resin 70%-75%, glass fiber 15-20%, titanium dioxide powder 2%-5%, rare earth 1%-2%, silicate 2%-8%, and then subjected to high temperature heat treatment at 300°C for 48 hours to obtain the modified high temperature resistant nylon material resin.

[0026] The DSC analysis comparison of high temperature resistant nylon material before and after modification is as follows: Test conditions: scanning temperature range 50 ~ 400 ℃, heating rate 10 ℃ / min, the melting peak of high temperature resistant nylon before modification is 326 ℃, the melting peak of high temperature resistant nylon after modification is 365 ℃, and the melting peak is increased by 39 ℃.

[0027] Thermogravimetric analysis of modified high temperature resistant nylon material is as follows: Experimental conditions: test scanning 50~700℃, 10℃ / min, N2 atmosphere. Figure 3 Thermogravimetric analysis diagram of modified high temperature resistant nylon material shows that the temperature of 5% thermal weight loss is 436℃, the temperature of 10% thermal weight loss is 447℃, and the complete decomposition temperature is 505℃. Therefore, the modified high temperature resistant nylon material can have good performance at 350℃, and can withstand a high temperature of 370℃ under short-term static conditions.

[0028] Reference Figure 4-Figure 6 The extrusion die mentioned in the present invention consists of a core mold 6.1 and a sleeve mold 6.2. The core mold 6.1 is inserted into the inner side of the sleeve mold 6.2. The core mold 6.1 is configured as a duckbill structure. A wire hole 6.1.1 is provided in the end of the duckbill structure. A guide groove 6.1.2 is provided between the wire holes 6.1.1. The sleeve mold 6.2 is configured as a cylindrical structure. The internal flow channel 6.2.1 on one side is in a bell-mouth shape, and the end molding area 6.2.2 on the other side is a flat hole structure.

[0029] The above-mentioned wire-passing holes 6.1.1 are provided with three groups. Three nickel-based alloy steel tubes encapsulating sheath layers 5 penetrate into the mold core 6.1 and pass through the wire-passing holes 6.1.1. At the same time, the high-temperature resistant nylon material flows through the gap between the guide groove 6.1.2 and the internal flow channel 6.2.1, and is extruded and wrapped on the outside of the three nickel-based alloy steel tubes encapsulating sheath layers 5, and comes out from the end molding area 6.2.2 together, and then is molded by cooling water to form an integrated high-temperature resistant nylon anti-corrosion layer 6. Example 3

[0030] The present invention provides a method for manufacturing a high temperature resistant and corrosion resistant submersible oil cable, comprising the following steps: Step 1, extruding the copper wire blank into a round copper conductor with a diameter of 5.0 mm, and nickel-plating the outer surface of the copper conductor 1 to prevent oxidation of the copper conductor; Step 2: On the outside of the copper conductor 1, a polyimide inner insulating layer 2 with an insulation thickness of 0.5 mm is tightly coated on the outside of the copper conductor 1 by using a twin-screw extruder that can be heated to 500° C. from polyimide granules; Step 3, using a modified high temperature resistant nylon material, tightly wrapped on the outside of the polyimide film inner insulation layer 2 by extrusion tube extrusion and by drawing holes, with an insulation thickness of 0.7 mm, to form a modified high temperature resistant nylon outer insulation layer 3; Step 4: Use glass fiber yarn and ceramic fiber yarn in a ratio of 1:1, and weave them tightly on the outside of the modified high-temperature resistant nylon outer insulation layer 3 to form an inorganic heat-insulating woven cushion layer 4 with a thickness of 0.5 mm; Step 5, a 0.8mm thick incoloy825 nickel-based alloy steel strip is passed through a shaping roller, longitudinally wrapped after shaping, and formed into a nickel-based alloy steel pipe by a laser welding method, and then drawn through a die to a diameter of 10.0mm, and tightly wrapped on the outside of the inorganic thermal insulation woven cushion layer 4 to form a sealed nickel-based alloy steel pipe packaging sheath layer 5, which can withstand a pressure of more than 50Mpa; Step 6: Through a specially designed extrusion die, the high temperature resistant nylon material is continuously extruded onto the outside of the three nickel-based alloy steel pipes placed in parallel, forming an integrated high temperature resistant nylon anti-corrosion layer 6, the thickness of which is 2 mm; Step 7: The monel nickel-based alloy steel strip is pressed and stacked to be armored on the outside of the integrated high-temperature resistant nylon anti-corrosion layer 6 in an interlocking manner to form a nickel-based alloy steel strip armor layer 7 with a size of 14.0×34.0 mm.

[0031] Specifically, the preparation method of the modified high temperature resistant nylon material is as follows: nylon resin, glass fiber, titanium dioxide powder, rare earth, silicate and other materials are heated at 260°C, and mechanically stirred to fully blend, and the modified mixed high temperature resistant nylon resin is obtained by dispersion polymerization through condensation, washing, drying and other methods. The modified high temperature resistant nylon material, glass fiber, titanium dioxide powder, rare earth, and silicate are mixed according to the mass proportion, nylon resin 70%-75%, glass fiber 15-20%, titanium dioxide powder 2%-5%, rare earth 1%-2%, silicate 2%-8%, and then subjected to high temperature heat treatment at 300°C for 48 hours to obtain the modified high temperature resistant nylon resin. Example 4

[0032] The present invention provides a method for manufacturing a high temperature resistant and corrosion resistant submersible oil cable, comprising the following steps: Step 1, drawing the copper wire blank into a round copper conductor with a diameter of 4.6 mm, and nickel-plating the outer surface of the copper conductor 1 to prevent oxidation of the copper conductor; Step 2: On the outside of the copper conductor 1, a polyimide inner insulating layer 2 with an insulation thickness of 0.5 mm is tightly coated on the outside of the copper conductor 1 by using a twin-screw extruder that can be heated to 500° C. from polyimide granules; Step 3, the modified high temperature resistant nylon material is tightly wrapped on the outside of the polyimide film inner insulation layer 2 by extrusion tube extrusion and true hole drawing, and the insulation thickness is 0.7mm to form the modified high temperature resistant nylon material outer insulation layer 3; Step 4: Glass fiber yarns and ceramic fiber yarns are tightly woven on the outside of the modified high-temperature resistant nylon material outer insulation layer 3 to form an inorganic heat-insulating woven cushion layer 4 with a thickness of 0.5 mm; Step 5: A duplex stainless steel 2205 nickel-based alloy steel strip with a thickness of 1.25 mm is passed through a shaping roller, longitudinally wrapped after shaping, and formed into a nickel-based alloy steel pipe by a laser welding method, and then drawn through a die to a diameter of 9.5 mm, and tightly wrapped on the outside of the inorganic thermal insulation woven cushion layer 4 to form a sealed nickel-based alloy steel pipe packaging sheath layer 5, which can withstand a pressure of more than 50 MPa; Step 6: Through a specially designed extrusion die, the high temperature resistant nylon material is continuously extruded onto the outside of the three nickel-based alloy steel pipes placed in parallel, forming an integrated high temperature resistant nylon anti-corrosion layer 6, the thickness of which is 2 mm; Step 7: The monel nickel-based alloy steel strip is pressed and stacked to be armored on the outside of the integrated high-temperature resistant nylon anti-corrosion layer 6 in an interlocking manner to form a nickel-based alloy steel strip armor layer 7 with a size of 13.5×32.5 mm.

[0033] Specifically, the preparation method of the modified high temperature resistant nylon material is as follows: nylon resin, glass fiber, titanium dioxide powder, rare earth, silicate and other materials are heated at 200°C, and mechanically stirred to fully blend, and the modified high temperature resistant mixed nylon resin is obtained by dispersion polymerization through condensation, washing, drying and other methods. The modified high temperature resistant nylon material, glass fiber, titanium dioxide powder, rare earth, and silicate are mixed according to the mass proportion, nylon resin 70%-75%, glass fiber 15-20%, titanium dioxide powder 2%-5%, rare earth 1%-2%, silicate 2%-8%, and then subjected to high temperature heat treatment at 300°C for 48 hours to obtain the modified high temperature resistant nylon material resin.

[0034] Comparative Example 1 Based on Example 2, unmodified high temperature resistant nylon material is used as the outer insulation layer, and the remaining steps are the same as Example 2.

[0035] Comparative Example 2 Based on Example 3, unmodified high temperature resistant nylon material is used as the outer insulation layer, and the remaining steps are the same as Example 3.

[0036] Comparative Example 4 Based on Example 4, the integrated high temperature resistant nylon anti-corrosion layer 6 is not used, and the remaining steps are the same as Example 4.

[0037] Take 0.5 meters of the cable samples prepared in Example 2, Example 3, Comparative Examples 1 and Comparative Examples 2, and test their insulation resistance at room temperature and pressure. Then seal the two ends of the sample with polyimide tape and place it horizontally in a closed tubular high temperature and high pressure test device. Then increase the temperature and pressure of the high temperature and high pressure test device to 350°C and 40Mpa for 168 hours to perform a high temperature and high pressure test and test the insulation resistance of the sample. Compare the changes in insulation resistance before and after the test. The performance changes are shown in Table 1.

[0038] Table 1 Comparison of insulation resistance effects before and after high temperature and high voltage tests of the embodiments and comparative examples

[0039] 0.5 m of the cable samples prepared in Example 4 and Comparative Example 4 were sampled respectively, and then both ends of the samples were sealed with polyimide tape and placed horizontally in a closed rectangular test device. A mixed solution of 20# engine oil containing 8% hydrogen sulfide and 3.6% sodium chloride was added to the device. The samples were heated to 121°C for 18 hours, then left to stand for 168 hours, and then their corrosion resistance changes were compared. The performance changes are shown in Table 2.

[0040] Table 2 Comparison of corrosion resistance effects of examples and comparative examples

[0041] By comparison, the present invention can meet the use conditions under the harsh downhole working conditions of static high temperature 370°C, pressure 50Mpa and strong acid and alkali corrosion, fully guaranteeing the power supply of the submersible unit in the downhole environment of high temperature, high pressure and high corrosion, ensuring production safety and service life, and improving oil production efficiency.

[0042] The above are only some preferred embodiments of the present invention. Any person skilled in the art may modify the above technical solutions or modify them into equivalent technical solutions. Therefore, the corresponding simple modifications or equivalent transformations made according to the technical solutions of the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A high temperature resistant submersible cable, comprising a copper conductor (1), a polyimide inner insulating layer (2), and a nickel-based alloy steel belt armor layer (7), wherein the copper conductor (1) is externally wrapped with a sintered polyimide inner insulating layer (2), and wherein: The modified high-temperature resistant nylon outer insulating layer (3) is extruded on the outside of the polyimide inner insulating layer (2), and the polyimide inner insulating layer (2) is tightly coated; the inorganic heat-insulating woven cushion layer (4) is woven on the outside of the modified high-temperature resistant nylon outer insulating layer (3); the nickel-based alloy steel tube encapsulating sheath layer (5) is encapsulated on the outside of the inorganic heat-insulating woven cushion layer (4); the modified high-temperature resistant nylon material is extruded on the outside of the nickel-based alloy steel tube encapsulating sheath layer (5) to form an integrated high-temperature resistant nylon anti-corrosion layer (6); and a nickel-based alloy steel belt armor layer (7) is installed on the outside of the integrated high-temperature resistant nylon anti-corrosion layer (6).

2. The high temperature resistant submersible cable according to claim 1 is characterized in that: The preparation method of the modified high temperature resistant nylon material is as follows: according to the mass proportion, 70%-75% nylon resin, 15%-20% glass fiber, 2%-5% titanium dioxide powder, 1%-2% rare earth, and 2%-8% silicate are heated at 260℃-300℃ and mechanically stirred to fully blend. Then, the modified mixed high-temperature resistant nylon resin is obtained by dispersion polymerization, condensation, washing, and drying methods, and then 2-3mm modified high-temperature resistant nylon material particles are made through granulation equipment.

3. The high temperature resistant submersible cable according to claim 2 is characterized in that: The inorganic heat-insulating woven mat layer (4) is made of one or more of mica fibers, quartz fibers, glass fibers and ceramic fibers.

4. The high temperature resistant submersible cable according to claim 3 is characterized in that: The nickel-based alloy steel pipe packaging materials include but are not limited to incoloy825, Alloy625, duplex stainless steel 2205 and duplex stainless steel 2507.

5. The high temperature resistant submersible cable according to claim 4 is characterized in that: The modified high-temperature resistant nylon material is extruded onto the outside of the nickel-based alloy steel pipe packaging sheath layer (5) through an extrusion die to form an integrated high-temperature resistant nylon anti-corrosion layer (6).

6. The high temperature resistant submersible cable according to claim 5 is characterized in that: The extrusion die is composed of a die core (6.1) and a die sleeve (6.2). The die core (6.1) is inserted into the inner side of the die sleeve (6.2). The die core (6.1) is configured as a duckbill structure. A wire hole ( 6.1.1), a guide groove (6.1.2) is provided between the wire holes (6.1.1); the mold sleeve (6.2) is set as a cylindrical structure, the internal flow channel (6.2.1) on one side is a bell-mouth shape, and the end molding area (6.2.2) on the other side is a flat hole structure.

7. The high temperature resistant submersible cable according to claim 6 is characterized in that: The wire-passing holes (6.1.1) are provided with three groups, and three nickel-based alloy steel tube encapsulating sheath layers (5) are inserted into the mold core (6.1) and pass through the wire-passing holes (6.1.1). At the same time, the high-temperature resistant nylon material flows through the gap formed by the guide groove (6.1.2) and the internal flow channel (6.2.1), and is extruded and wrapped on the outside of the three nickel-based alloy steel tube encapsulating sheath layers (5), and comes out from the end molding area (6.2.2) together, and then is molded by cooling water to form an integrated high-temperature resistant nylon anti-corrosion layer (6).

8. The high temperature resistant submersible cable according to claim 7 is characterized in that: The copper conductor (1) is formed by extruding a copper wire blank into a round copper conductor using a copper extruder. The copper conductor (1) is nickel-plated on the outside to prevent oxidation of the copper conductor. The diameter of the copper conductor (1) is 3.0 mm to 7.0 mm. The thickness of the polyimide inner insulation layer (2) is 0.3 mm to 0.8 mm. The thickness of the modified high-temperature resistant nylon outer insulation layer (3) is 0.5 mm to 1.2 mm. The thickness of the inorganic heat-insulating braided cushion layer (4) is 0.3 mm to 1.0 mm. The thickness of the nickel-based alloy steel tube encapsulation sheath layer (5) is 0.7 mm to 1.5 mm. The thickness of the integrated high-temperature resistant nylon anti-corrosion layer (6) is 1.0 mm to 2.0 mm. The thickness of the nickel-based alloy steel belt armor layer (7) is 0.3 mm to 0.5 mm.

9. The method for preparing a high temperature resistant submersible oil cable according to claim 7, characterized in that The following steps are involved: Step 1, extruding a copper wire blank into a round copper conductor, the outer surface of the copper conductor (1) is nickel-plated to prevent oxidation of the copper conductor, and the diameter of the copper conductor (1) is 3.0 mm to 7.0 mm; Step 2: On the outside of the circular copper conductor (1), a polyimide insulating granular material is extruded onto the outside of the copper conductor (1) using a twin-screw extruder that can be heated to 500° C. to form a polyimide inner insulating layer (2); Step 3: On the outside of the polyimide inner insulation layer (2), a modified high-temperature resistant nylon material is tightly extruded on the outside of the polyimide inner insulation layer to form a modified high-temperature resistant nylon outer insulation layer (3); Step 4: one or more of mica fiber, quartz fiber, glass fiber and ceramic fiber made of inorganic material is tightly woven on the outside of the modified high temperature resistant nylon outer insulation layer (3) to form an inorganic thermal insulation woven mat layer (4); Step 5, the nickel-based alloy steel strip passes through a shaping roller, and after shaping, is longitudinally wrapped around the outside of the inorganic heat-insulating woven cushion layer (4), and a laser welding method is used to form a nickel-based alloy steel tube, and then the tube is drawn and sized through a die, and tightly wrapped around the outside of the inorganic heat-insulating woven cushion layer (4), forming a sealed nickel-based alloy steel tube packaging sheath layer (5), which can withstand a pressure of more than 50 MPa and has good corrosion resistance; Step 6, using the modified high temperature resistant nylon material and using an extrusion die, the three nickel-based alloy steel tubes encapsulating sheath layers (5) are passed through the die core (6.1) and through the wire hole (6.1.1), and at the same time, the high temperature resistant nylon material flows through the gap between the guide groove (6.1.2) and the internal flow channel (6.2.1), and is extruded and wrapped around the outside of the three nickel-based alloy steel tubes encapsulating sheath layers (5), and comes out from the end molding area (6.2.2), and then is molded by cooling water to form an integrated high temperature resistant nylon anti-corrosion layer (6); Step 7: The nickel-based alloy steel strip is laminated by pressing to form an interlocking armoring layer (7) on the outside of the integrated high-temperature resistant nylon anti-corrosion layer (6) on the outside of the nickel-based alloy steel tube encapsulation sheath layer (5).

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