Device for testing cathode protection effect of directional drilling crossing section pipeline

Abstract

The invention discloses a directional drilling crossing section pipeline cathode protection effect testing device, which comprises a testing pipe and a testing box, and is characterized in that the testing pipe comprises a plurality of insulating connecting pipes which are sequentially and coaxially connected along the vertical direction; a self-corrosion test piece, a high-purity zinc reference electrode, a polarization test piece and a saturated copper sulfate reference electrode are sequentially arranged on the outer pipe wall of the insulating connecting pipe from top to bottom; the self-corrosion test piece, the high-purity zinc reference electrode, the polarization test piece and the saturated copper sulfate reference electrode are connected with the test box through a first wire, a second wire, a third wire and a fourth wire respectively, the first wire, the second wire, the third wire and the fourth wire are all located in the test tube, and the test box is connected with a fifth wire used for being connected with a crossing section pipeline. The invention aims to provide the cathode protection effect testing device for the directional drilling crossing section pipeline, which can accurately test the polarization potentials of the directional drilling crossing section pipeline at different depth positions and further evaluate the cathode protection effect of the pipeline at the different depth positions.

Description

Technical Field

[0001] The invention belongs to the technical field of cathodic protection of buried steel pipelines, and particularly relates to the evaluation of the cathodic protection effect of a directional drilled pipeline crossing section. The invention is mainly used to accurately test the polarization potential of pipelines at different depths in the directional drilled pipeline crossing section, and evaluate the cathodic protection effect of the pipeline crossing section. Background Art

[0002] The horizontal directional drilling crossing method is a common laying method for pipelines in shallow buried areas such as roads, railways and rivers. It has the characteristics of not destroying the stratum structure, occupying less land for construction, not being affected by seasons, and having a short construction period. From 2016 to 2019, the length of the directional drilling crossing section of the pipeline of Beijing Gas Group's various projects was about 35 kilometers, with a total of more than 42 locations, with an average length of 300-500 meters. It was mainly affected by the drainage site. The longest one-way was 1921 meters for DN1000 on the West Sixth Ring Road, and the longest two-way parallel was 1200 meters each for DN500 and DN1000 on the Beijing-Taipei Expressway, with a total length of 2400 meters. At the same time, this type of pipeline laying method is prone to damage to the pipeline anti-corrosion layer regardless of the severity of the geological conditions. During the back-pulling process of the horizontal directional drilling crossing section pipeline, especially in the hard rock under the river channel, problems such as unsmooth pre-expansion holes, unsaturated bentonite slurry, and low directional control accuracy often occur, which can easily damage and scratch the anti-corrosion layer, and even scratch it to expose the metal pipe body, becoming a hidden danger to safe operation. The special construction method of directional drilling often causes damage to the pipeline anti-corrosion layer, and it is impossible to test and evaluate the cathodic protection effect of the deep layer, which becomes a blind spot in safety management. The conventional testing method of the directional drilling crossing section pipeline cannot test the real polarization potential of the pipeline at the crossing depth. It can only test the on-off potential on the surface to judge the cathodic protection effect of the crossing section pipeline. Therefore, there is an urgent need for a test device that can test the real polarization potential of the pipeline corresponding to the soil polarization effect at different depths of the directional drilling crossing section. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a device for testing the cathodic protection effect of a directional drilling section pipeline, which can accurately test the polarization potential of the directional drilling section pipeline at different depths, and thus can evaluate the cathodic protection effect of the pipeline at different depths.

[0004] The invention discloses a test device for cathodic protection effect of a directional drilling pipeline crossing section, comprising a test tube and a test box, wherein the test tube comprises a plurality of insulating connecting tubes which are coaxially connected in sequence along a vertical direction, wherein a self-corrosion test piece, a high-purity zinc reference electrode, a polarization test piece and a saturated copper sulfate reference electrode are arranged in sequence on the outer tube wall of the insulating connecting tube from top to bottom, wherein the self-corrosion test piece, the high-purity zinc reference electrode, the polarization test piece and the saturated copper sulfate reference electrode are connected to the test box through a first wire, a second wire, a third wire and a fourth wire respectively, wherein the first wire, the second wire, the third wire and the fourth wire are all located in the test tube, and the test box is connected with a fifth wire for connecting to the crossing section pipeline.

[0005] The invention discloses a test device for cathodic protection effect of a directional drilling pipeline through section, wherein the self-corrosion test piece is connected to one end of a first wire, the other end of the first wire passes through the pipe wall of an insulating connecting pipe into the test pipe and extends from the upper pipe opening of the test pipe, the other end of the first wire is connected to a test box, the high-purity zinc reference electrode is connected to one end of a second wire, the other end of the second wire passes through the pipe wall of an insulating connecting pipe into the test pipe and extends from the upper pipe opening of the test pipe, the other end of the second wire is connected to the test box, the polarization test piece is connected to one end of a third wire, the other end of the third wire passes through the pipe wall of an insulating connecting pipe into the test pipe and extends from the upper pipe opening of the test pipe, the other end of the third wire is connected to the test box, the saturated copper sulfate reference electrode is plugged into the pipe wall of the insulating connecting pipe, the two ends of the saturated copper sulfate reference electrode are respectively located on the inner side and the outer side of the insulating connecting pipe, the end of the saturated copper sulfate reference electrode located on the inner side of the insulating connecting pipe is connected to one end of a fourth wire, the other end of the fourth wire extends from the upper pipe opening of the test pipe, and the other end of the fourth wire is connected to the test box.

[0006] The present invention discloses a test device for the cathodic protection effect of a directional drilling pipeline through section, wherein the outer pipe wall of the insulating connecting pipe is provided with a first clamping groove, a second clamping groove, a third clamping groove and a through hole in sequence from top to bottom, the first clamping groove, the second clamping groove and the third clamping groove are all arranged along the circumference of the insulating connecting pipe, the first clamping groove is provided with a first wire hole penetrating the pipe wall of the insulating connecting pipe, the second clamping groove is provided with a second wire hole penetrating the pipe wall of the insulating connecting pipe, the third clamping groove is provided with a third wire hole penetrating the pipe wall of the insulating connecting pipe, the self-corrosion test piece, the high-purity zinc reference electrode and the polarization test piece are all annular structures, the self-corrosion test piece, the high-purity zinc reference electrode and the polarization test piece are respectively clamped in the first clamping groove, the second clamping groove and the third clamping groove, the other end of the first wire passes through the pipe wall of the insulating connecting pipe through the first wire hole, the other end of the second wire passes through the pipe wall of the insulating connecting pipe through the second wire hole, the other end of the third wire passes through the pipe wall of the insulating connecting pipe through the third wire hole, and the saturated copper sulfate reference electrode is plugged into the through hole.

[0007] The present invention discloses a test device for the cathodic protection effect of a directional drilling pipeline crossing section, wherein the self-corrosion test piece comprises two semi-annular self-corrosion test piece halves, the two self-corrosion test piece halves are relatively clamped in a first clamping slot, two first wire holes are provided, the two first wire holes are respectively provided at positions of the first clamping slot corresponding to the two self-corrosion test piece halves, the first wire comprises two first branch wires, one ends of the two first branch wires are respectively connected to the two self-corrosion test piece halves, the other ends of the two first branch wires respectively pass through the two first wire holes into the test tube and merge into the other end of the first wire.

[0008] The present invention discloses a test device for the cathodic protection effect of a directional drilling crossing section pipeline, wherein the high-purity zinc reference electrode comprises two high-purity zinc reference electrode halves both in the form of semi-annular shapes, the two high-purity zinc reference electrode halves are relatively clamped in a second clamping slot, the number of the second wire holes is set to two, the two second wire holes are respectively arranged at positions of the second clamping slot corresponding to the two high-purity zinc reference electrode halves, the second wire comprises two second branch wires, one ends of the two second branch wires are respectively connected to the two high-purity zinc reference electrode halves, the other ends of the two second branch wires respectively pass through the two second wire holes into the test tube and merge into the other end of the second wire.

[0009] The invention discloses a test device for cathodic protection effect of a directional drilling pipeline crossing section, wherein the polarization test piece comprises two polarization test piece halves both in a semi-circular shape, the two polarization test piece halves are relatively clamped in a third clamping slot, the third wire hole is provided with two, the two third wire holes are respectively arranged at positions of the third clamping slot corresponding to the two polarization test piece halves, the third wire comprises two third branch wires, one ends of the two third branch wires are respectively connected to the two polarization test piece halves, the other ends of the two third branch wires respectively pass through the two third wire holes to enter the test tube and merge into the other end of the third wire.

[0010] The present invention provides a device for testing the cathodic protection effect of a directional drilling crossing section pipeline, wherein two adjacent insulating connecting tubes are respectively an upper insulating connecting tube and a lower insulating connecting tube, the upper insulating connecting tube is located above the lower insulating connecting tube, the lower end of the upper insulating connecting tube is provided with an internal thread, the upper end of the lower insulating connecting tube is provided with an external thread, and the upper insulating connecting tube and the lower insulating connecting tube are connected by the internal thread and the external thread.

[0011] The invention discloses a test device for the cathodic protection effect of a pipeline in a directional drilling crossing section, wherein an insulating plate is arranged in the test box, and a self-corrosion test piece terminal, a high-purity zinc reference electrode terminal, a polarization test piece terminal, a saturated copper sulfate reference electrode terminal and a pipeline terminal are arranged on the insulating plate, and the self-corrosion test piece terminal, the high-purity zinc reference electrode terminal, the polarization test piece terminal and the saturated copper sulfate reference electrode terminal are all provided in plurality, and a plurality of insulating connecting pipes, a plurality of self-corrosion test piece terminals, a plurality of high-purity zinc reference electrode terminals, a plurality of polarization test piece terminals and a plurality of saturated copper sulfate reference electrode terminals are arranged in one-to-one correspondence, and the self-corrosion test piece terminals on the insulating connecting pipes are provided with a plurality of high-purity zinc reference electrode terminals, a plurality of polarization test piece terminals and a plurality of saturated copper sulfate reference electrode terminals. The test piece is connected to the self-corrosion test piece terminal corresponding to the insulating connecting tube through a first wire, the high-purity zinc reference electrode on the insulating connecting tube is connected to the high-purity zinc reference electrode terminal corresponding to the insulating connecting tube through a second wire, the polarization test piece on the insulating connecting tube is connected to the polarization test piece terminal corresponding to the insulating connecting tube through a third wire, the saturated copper sulfate reference electrode on the insulating connecting tube is connected to the saturated copper sulfate reference electrode terminal corresponding to the insulating connecting tube through a fourth wire, and multiple polarization test piece terminals are respectively connected to pipeline terminals through control switches, and the pipeline terminal is connected to a fifth wire for connecting to the crossing section pipeline.

[0012] The present invention is different from the prior art in that the present invention is used to bury the test pipe at the position where the pipeline of the directional drilling section passes through and / or passes through the ground, and then the self-corrosion test piece, the high-purity zinc reference electrode, the polarization test piece and the saturated copper sulfate reference electrode in each insulating connecting pipe are connected to the test box above the ground through the first wire, the second wire, the third wire and the fourth wire respectively, and then the test box is connected to the pipeline of the directional drilling section through the fifth wire. The saturated copper sulfate reference electrode in the present invention is arranged below the polarization test piece, which can prevent the copper sulfate liquid from contaminating the polarization test piece. The polarization test piece and the reference electrode are close to each other, which can better eliminate the IR drop and more accurately test the polarization potential of the polarization test piece. At the same time, a high-purity zinc reference electrode is arranged, and multiple reference electrodes are calibrated with each other, which can eliminate the test error caused by the reference electrode deviation. Compared with the traditional test method, the present invention can accurately test the polarization potential of the pipeline of the directional drilling section at different depths by arranging polarization test pieces at different depths, and then can evaluate the cathodic protection effect of pipelines at different depths.

[0013] The present invention will be further described below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of a device for testing the cathodic protection effect of a directional drilling pipeline through a section of the present invention;

[0015] Figure 2It is a schematic diagram of the internal structure of the test box of the directional drilling through-section pipeline cathodic protection effect test device of the present invention;

[0016] Figure 3 It is a front view of the insulating connecting pipe of the cathodic protection effect testing device for directional drilling through-section pipeline of the present invention;

[0017] Figure 4 For along Figure 3 Sectional view along line AA;

[0018] Figure 5 It is a front cross-sectional view of the insulating connecting pipe of the directional drilling through-section pipeline cathodic protection effect testing device of the present invention;

[0019] Figure 6 It is a schematic diagram of the installation position of the test tube in the present invention when in use. DETAILED DESCRIPTION

[0020] like Figure 1 As shown, combined with Figure 2-6 As shown, the cathodic protection effect testing device for a directional drilling pipeline crossing section of the present invention comprises a test tube 1 and a test box 2, wherein the test tube 1 comprises a plurality of insulating connecting tubes 5 coaxially connected in sequence vertically, wherein the insulating connecting tubes 5 are polytetrafluoroethylene connecting tubes, and the outer tube wall of the insulating connecting tube 5 is provided with a self-corrosion test piece 6, a high-purity zinc reference electrode 8, a polarization test piece 10 and a saturated copper sulfate reference electrode 12 in sequence from top to bottom, wherein the self-corrosion test piece 6, the high-purity zinc reference electrode 8, the polarization test piece 10 and the saturated copper sulfate reference electrode 12 are respectively connected to the test box 2 through a first wire 7, a second wire 9, a third wire 11 and a fourth wire 13, wherein the first wire 7, the second wire 9, the third wire 11 and the fourth wire 13 are all located in the test tube 1, and the test box 2 is connected with a fifth wire 3 for connecting to the crossing section pipeline 4. The first wire 7, the second wire 9, the third wire 11, the fourth wire 13 and the fifth wire 3 can all be cables.

[0021] In the present invention, each insulating connecting tube 5 is provided with a self-corrosion test piece 6, a high-purity zinc reference electrode 8, a polarization test piece 10 and a saturated copper sulfate reference electrode 12, and the self-corrosion test piece 6, the high-purity zinc reference electrode 8, the polarization test piece 10 and the saturated copper sulfate reference electrode 12 are respectively connected to the test box 2 through separate wires, that is, each insulating connecting tube 5 constitutes a test unit. Since multiple insulating connecting tubes 5 are arranged coaxially vertically, each insulating connecting tube 5 can test the polarization potential at different depths of the traversing section pipeline 4, that is, the insulating connecting tube 5 located at the top can test the polarization potential at a shallower depth, and the insulating connecting tube 5 located at the bottom can test the polarization potential at a deeper depth.

[0022] In actual use, the length and number of the insulating connecting tubes 5 can be determined according to actual working conditions.

[0023] like Figure 1 As shown, combined with Figure 2-5 As shown, the cathodic protection effect test device of the directional drilling through section pipeline of the present invention, wherein the self-corrosion test piece 6 is connected to one end (i.e., the lower end) of the first wire 7, and the other end (i.e., the upper end) of the first wire 7 passes through the pipe wall of the insulating connecting pipe 5 into the test pipe 1 and extends from the upper pipe mouth of the test pipe 1, at which time the other end of the first wire 7 comes above the ground, and then the other end of the first wire 7 is connected to the test box 2. The high-purity zinc reference electrode 8 is connected to one end (i.e., the lower end) of the second wire 9, and the other end (i.e., the upper end) of the second wire 9 passes through the pipe wall of the insulating connecting pipe 5 into the test pipe 1 and extends from the upper pipe mouth of the test pipe 1, at which time the other end of the second wire 9 comes above the ground, and then the other end of the second wire 9 is connected to the test box 2. The polarization test piece 10 is connected to one end (i.e., the lower end) of the third wire 11, and the other end (i.e., the upper end) of the third wire 11 passes through the wall of the insulating connecting tube 5 into the test tube 1 and extends from the upper tube mouth of the test tube 1. At this time, the other end of the third wire 11 comes above the ground, and then the other end of the third wire 11 is connected to the test box 2. The saturated copper sulfate reference electrode 12 is plugged into the wall of the insulating connecting tube 5, and the two ends of the saturated copper sulfate reference electrode 12 are respectively located on the inner side and the outer side of the insulating connecting tube 5. The end of the saturated copper sulfate reference electrode 12 located on the inner side of the insulating connecting tube 5 is connected to one end (i.e., the lower end) of the fourth wire 13, and the other end (i.e., the upper end) of the fourth wire 13 extends from the upper tube mouth of the test tube 1. At this time, the other end of the fourth wire 13 comes above the ground, and then the other end of the fourth wire 13 is connected to the test box 2.

[0024] like Figure 3-5As shown, the cathodic protection effect testing device of the directional drilling through section pipeline of the present invention, wherein the outer pipe wall of the insulating connecting pipe 5 is provided with a first card slot, a second card slot, a third card slot and a through hole in sequence from top to bottom, the first card slot, the second card slot and the third card slot are arranged along the circumference of the insulating connecting pipe 5, the first card slot is provided with a first wire hole 22 penetrating the pipe wall of the insulating connecting pipe 5, the second card slot is provided with a second wire hole 26 penetrating the pipe wall of the insulating connecting pipe 5, the third card slot is provided with a third wire hole 27 penetrating the pipe wall of the insulating connecting pipe 5, the self-corrosion The self-corrosion test piece 6, the high-purity zinc reference electrode 8 and the polarization test piece 10 are all annular structures. The self-corrosion test piece 6, the high-purity zinc reference electrode 8 and the polarization test piece 10 are respectively clamped in the first clamping slot, the second clamping slot and the third clamping slot. The other end of the first wire 7 passes through the wall of the insulating connecting tube 5 through the first wire hole 22, the other end of the second wire 9 passes through the wall of the insulating connecting tube 5 through the second wire hole 26, the other end of the third wire 11 passes through the wall of the insulating connecting tube 5 through the third wire hole 27, and the saturated copper sulfate reference electrode 12 is plugged into the through hole.

[0025] After the self-corrosion test piece 6, the high-purity zinc reference electrode 8 and the polarization test piece 10 are respectively clamped in the first clamping slot, the second clamping slot and the third clamping slot, only the outer peripheral sides of the self-corrosion test piece 6, the high-purity zinc reference electrode 8 and the polarization test piece 10 are exposed and in contact with the soil.

[0026] The self-corrosion test piece 6 is connected to the first wire 7 by copper welding, and the connection position between the two is sealed and waterproof. Similarly, the polarization test piece 10 is also connected to the third wire 11 by copper welding, and the connection position between the two is sealed and waterproof.

[0027] like Figure 4 As shown, the cathodic protection effect test device of the directional drilling through section pipeline of the present invention, wherein the self-corrosion test piece 6 includes two semi-circular self-corrosion test piece halves, the two self-corrosion test piece halves are relatively clamped in the first clamping slot, the first wire hole 22 is set to two, and the two first wire holes 22 are respectively arranged at the positions of the first clamping slot corresponding to the two self-corrosion test piece halves, and the first wire 7 includes two first branch wires 23, one end of the two first branch wires 23 is respectively connected to the two self-corrosion test piece halves, and the other ends of the two first branch wires 23 pass through the two first wire holes 22 respectively into the test tube 1 and merge into the other end of the first wire 7. One end of the two first branch wires 23 separated from each other is one end of the first wire 7, and the other end of the first wire 7 formed by merging the other ends of the two first branch wires 23 passes through the upper pipe mouth of the test tube 1 and is connected to the test box 2.

[0028] The present invention discloses a test device for cathodic protection effect of a directional drilling pipeline through section, wherein the high-purity zinc reference electrode 8 comprises two high-purity zinc reference electrode halves both in a semi-circular shape, the two high-purity zinc reference electrode halves are relatively clamped in the second clamping slot, the number of the second wire holes 26 is set to two, and the two second wire holes 26 are respectively arranged at positions of the second clamping slot corresponding to the two high-purity zinc reference electrode halves, and the second wire 9 comprises two second branch wires 24, one end of the two second branch wires 24 is respectively connected to the two high-purity zinc reference electrode halves, and the other ends of the two second branch wires 24 respectively pass through the two second wire holes 26 into the test tube 1 and merge into the other end of the second wire 9. One end of the two second branch wires 24 separated from each other is one end of the second wire 9, and the other end of the second wire 9 formed by merging the other ends of the two second branch wires 24 passes through the upper pipe opening of the test tube 1 and is connected to the test box 2.

[0029] The present invention discloses a test device for cathodic protection effect of a directional drilling pipeline through section, wherein the polarization test piece 10 comprises two polarization test piece halves both in a semi-circular shape, the two polarization test piece halves are relatively clamped in the third clamping slot, the third wire hole 27 is provided with two, the two third wire holes 27 are respectively arranged at positions of the third clamping slot corresponding to the two polarization test piece halves, the third wire 11 comprises two third branch wires 25, one end of the two third branch wires 25 are respectively connected to the two polarization test piece halves, the other ends of the two third branch wires 25 respectively pass through the two third wire holes 27 into the test tube 1 and merge into the other end of the third wire 11. One end of the two third branch wires 25 separated from each other is one end of the third wire 11, and the other end of the third wire 11 formed by merging the other ends of the two third branch wires 25 passes through the upper pipe opening of the test tube 1 and is connected to the test box 2.

[0030] The present invention provides a test device for the cathodic protection effect of a directional drilling pipeline through a section, wherein two adjacent insulating connecting tubes 5 are respectively an upper insulating connecting tube and a lower insulating connecting tube, wherein the upper insulating connecting tube is located above the lower insulating connecting tube, wherein the lower end of the upper insulating connecting tube is provided with an internal thread 28, and the upper end of the lower insulating connecting tube is provided with an external thread 21, wherein the upper insulating connecting tube and the lower insulating connecting tube are connected via the internal thread 28 and the external thread 21. In order to realize the connection of the two adjacent insulating connecting tubes 5 via the internal thread 28 and the external thread 21, as shown in FIG. Figure 3 , 5 As shown, an external thread 21 is provided at the upper end of each insulating connecting tube 5 and an internal thread 28 is provided at the lower end. The internal thread 28 matches the external thread 21 , so that adjacent upper insulating connecting tubes and lower insulating connecting tubes can be connected via the internal thread 28 and the external thread 21 .

[0031] like Figure 2As shown, the cathodic protection effect testing device for a directional drilling crossing section pipeline of the present invention, wherein the test box 2 is provided with an insulating plate 14, and the insulating plate 14 is provided with a self-corrosion test piece terminal 18, a high-purity zinc reference electrode terminal 20, a polarization test piece terminal 15, a saturated copper sulfate reference electrode terminal 19 and a pipeline terminal 17, and the self-corrosion test piece terminal 18, the high-purity zinc reference electrode terminal 20, the polarization test piece terminal 15 and the saturated copper sulfate reference electrode terminal 19 are all provided in plurality, and a plurality of insulating connecting tubes 5, a plurality of self-corrosion test piece terminals 18, a plurality of high-purity zinc reference electrode terminals 20, a plurality of polarization test piece terminals 15 and a plurality of saturated copper sulfate reference electrode terminals 19 are arranged one by one, and the self-corrosion test piece terminals 18 on the insulating connecting tube 5, a plurality of high-purity zinc reference electrode terminals 20, a plurality of polarization test piece terminals 15 and a plurality of saturated copper sulfate reference electrode terminals 19 are arranged in a one-to-one correspondence. The sheet 6 is connected to the self-corrosion test piece terminal 18 corresponding to the insulating connecting tube 5 through the first wire 7, the high-purity zinc reference electrode 8 on the insulating connecting tube 5 is connected to the high-purity zinc reference electrode terminal 20 corresponding to the insulating connecting tube 5 through the second wire 9, the polarization test piece 10 on the insulating connecting tube 5 is connected to the polarization test piece terminal 15 corresponding to the insulating connecting tube 5 through the third wire 11, the saturated copper sulfate reference electrode 12 on the insulating connecting tube 5 is connected to the saturated copper sulfate reference electrode terminal 19 corresponding to the insulating connecting tube 5 through the fourth wire 13, and multiple polarization test piece terminals 15 are respectively connected to the pipeline terminal 17 through the control switch 16, and the pipeline terminal 17 is connected to the fifth wire 3 used to connect to the crossing section pipeline 4.

[0032] Since the number of insulating connecting tubes 5 can be determined according to actual working conditions, the number of the connecting posts and control switches 16 corresponding to the insulating connecting tubes 5 should also be determined according to actual working conditions.

[0033] like Figure 6As shown, the present invention is different from the prior art in that the present invention is used to bury the test pipe 1 at the position where the pipeline 4 of the directional drilling section enters and / or passes through the ground, and then the self-corrosion test piece 6, the high-purity zinc reference electrode 8, the polarization test piece 10 and the saturated copper sulfate reference electrode 12 in each insulating connecting pipe 5 are connected to the test box 2 located above the ground through the first wire 7, the second wire 9, the third wire 11 and the fourth wire 13, respectively, and then the test box 2 is connected to the pipeline 4 of the crossing section through the fifth wire 3. The saturated copper sulfate reference electrode 12 in the present invention is arranged below the polarization test piece 10, which can prevent the copper sulfate liquid from contaminating the polarization test piece 10. The polarization test piece 10 and the reference electrode are close, which can better eliminate the IR drop and more accurately test the polarization potential of the polarization test piece 10. At the same time, the high-purity zinc reference electrode 8 is arranged, and multiple reference electrodes are calibrated with each other, which can eliminate the test error caused by the reference electrode deviation. Compared with the traditional testing method, the present invention can accurately test the polarization potential of the directional drilling traversing section pipeline 4 at different depths by setting the polarization test piece 10 at different depths, and then evaluate the cathodic protection effect of the pipeline 4 at different depths to meet the growing market demand.

[0034] like Figure 1-5 As shown, the specific structure of the present invention is further described below with a specific embodiment.

[0035] (1) According to the actual working conditions, four insulating connecting tubes 5 made of polytetrafluoroethylene are customized. The connecting tube 5 is 1.5 m long, 10 cm in outer diameter, hollow inside, and 6 cm in inner diameter. An outer thread 21 is made on the upper end of the connecting tube 5, and an inner thread 28 is made on the lower end. Three annular grooves and a circular through hole are made near the lower end. The width of each groove is 0.64 cm and the depth is 1 cm. The diameter of the circular through hole is 2 cm. Two circular holes (i.e., the above-mentioned wire holes) are drilled on each groove for passing the wires.

[0036] (2) Customize 4 polarization test pieces 10 with the same or similar material as the directional drilling section pipeline 4. Each polarization test piece 10 is composed of two semi-circular polarization test piece halves. The total surface area of ​​the polarization test piece 10 is 20 cm 2 The width of the circular ring is 0.63 cm. The two third branch wires 25 are connected to the two semi-circular polarization test piece halves by brazing. The remaining sides of the polarization test piece halves except the outer peripheral side and the connection position with the third branch wires 25 are all coated with epoxy glue. The two semi-circular polarization test piece halves are installed on the third card slot of the connecting tube 5. The two third branch wires 25 pass through the two third wire holes 27 on the third card slot and enter the inside of the connecting tube 5. Then, the two third branch wires 25 are combined into one third wire 11.

[0037] (3) Customize 4 self-corrosion test pieces 6 with the same or similar material as the directional drilling crossing section pipeline 4. Each self-corrosion test piece 6 consists of two semi-circular self-corrosion test piece halves. The total surface area of ​​the self-corrosion test piece 6 is 20 cm 2 The width of the circular ring is 0.63 cm. The two first branch conductors 23 are connected to the two semi-circular self-corrosion test piece halves by brazing. The other side surfaces of the self-corrosion test piece halves except the outer peripheral side surface and the connection position with the first branch conductors 23 are all coated with epoxy glue. The two semi-circular self-corrosion test piece halves are installed on the first card slot of the connecting tube 5. The two first branch conductors 23 pass through the two first wire holes 22 on the first card slot and enter the interior of the connecting tube 5. Then, the two first branch conductors 23 are combined into one first conductor 7.

[0038] (4) Four high-purity zinc reference electrodes 8 are customized, each of which is customized into two semi-circular high-purity zinc reference electrode halves, and the total surface area of ​​the high-purity zinc reference electrode 8 is 20 cm 2 The width of the circular ring is 0.63 cm. The high-purity zinc reference electrode half is crimped and connected to the second branch conductor 24 through the internal steel core, and the connection position between the two is insulated with anti-corrosion tape. The two semi-circular high-purity zinc reference electrode halves are installed on the second card slot of the connecting tube 5, and the two second branch conductors 24 respectively pass through the two second wire holes 26 on the second card slot and enter the connecting tube 5, and then the two second branch conductors 24 are combined into a second conductor 9.

[0039] (5) Four saturated copper sulfate reference electrodes 12 are customized. The diameter of the saturated copper sulfate reference electrode 12 is 1.8 cm. After the saturated copper sulfate reference electrode 12 is connected to the fourth wire 13, it is inserted into the prefabricated circular through hole of the connecting tube 5 and fixed with glass glue.

[0040] (6) After installing a self-corrosion test piece 6, a polarization test piece 10, a high-purity zinc reference electrode 8, and a saturated copper sulfate reference electrode 12 on each insulating connecting pipe 5, the pipe is placed in an installation well drilled on the side of the directional drilled through section pipeline 4. The installation well is drilled for 6 m, and each connecting pipe is 1.5 m long. After each connecting pipe 5 is placed in the well, the lower connecting pipe 5 is threadedly connected with the upper connecting pipe 5 to form a test pipe 1. All wires are inserted into the test pipe 1 and then led out to the ground. The self-corrosion test piece 6, polarization test piece 10, high-purity zinc reference electrode 8, and saturated copper sulfate reference electrode 12 of each connecting pipe 5 are connected to a separate wire.

[0041] (7) A test box 2 is customized, and an insulating plate 14, four polarization test strip terminals 15, four self-corrosion test strip terminals 18, four saturated copper sulfate reference electrode terminals 19, four high-purity zinc reference electrode terminals 20, four control switches 16 and one pipeline terminal 17 are provided in the test box 2. The four polarization test strip terminals 15 are respectively connected to the four control switches 16, and the four control switches 16 are all connected to the pipeline terminal 17.

[0042] (8) All the wires leading to the ground are connected to the test box 2, and the wires of the self-corrosion test piece 6, the polarization test piece 10, the high-purity zinc reference electrode 8 and the saturated copper sulfate reference electrode 12 are respectively connected to the corresponding terminals in the test box 2, that is, the first wires 7 of the four insulating connecting tubes 5 are respectively connected to the four self-corrosion test piece terminals 18, the second wires 9 of the four insulating connecting tubes 5 are respectively connected to the four high-purity zinc reference electrode terminals 20, the third wires 11 of the four insulating connecting tubes 5 are respectively connected to the four polarization test piece terminals 15, and the fourth wires 13 of the four insulating connecting tubes 5 are respectively connected to the four saturated copper sulfate reference electrode terminals 19. Finally, a fifth wire 3 is connected from the directional drilling section pipeline 4 to the pipeline terminal 17 in the test box 2.

[0043] When measuring the polarization potential, firstly, the control switch 16 is in the connected state, that is, the section of pipeline 4 is connected to the polarization test piece 10 through the fifth wire 3, the pipeline terminal 17, the control switch 16, the polarization test piece terminal 15, and the third wire 11 in sequence, and the connected state is maintained for a period of time to complete the polarization of the polarization test piece 10. Then, using a potential measuring device, such as a multimeter, the positive terminal of the multimeter is connected to the polarization test piece terminal 15, and the negative terminal is connected to the saturated copper sulfate reference electrode terminal 19, the power-on potential of the pipeline 4 can be measured, and then the power-off potential of the pipeline 4 can be measured after disconnecting the control switch 16. In order to make the measured polarization potential more accurate, the negative terminal of the multimeter can be connected to the high-purity zinc reference electrode terminal 20, and the on-off potential of the pipeline 4 can be measured again, and the average of the on-off potential measured when the negative terminal of the multimeter is connected to the saturated copper sulfate reference electrode 12 can be obtained, so that a more accurate polarization potential can be obtained.

[0044] When measuring the self-corrosion potential, the positive terminal of the multimeter is connected to the pipeline terminal 17, and the negative terminal is connected to the saturated copper sulfate reference electrode 12, and the self-corrosion potential of the pipeline 4 is measured. In order to make the measured self-corrosion potential more accurate, the negative terminal of the multimeter can be connected to the high-purity zinc reference electrode terminal 20, and the self-corrosion potential of the pipeline 4 can be measured again. The average of the self-corrosion potential measured when the negative terminal of the multimeter is connected to the saturated copper sulfate reference electrode 12 can be obtained, and a more accurate self-corrosion potential can be obtained.

[0045] The cathodic protection effect of the pipeline 4 can be judged according to the measured polarization potential (i.e., the power-off potential), and can also be judged according to the difference between the measured polarization potential and the self-corrosion potential. By comparing the power-on potential with the self-corrosion potential, it can be judged whether the pipeline 4 has taken cathodic protection measures, that is, when the power-on potential is the same as the self-corrosion potential or the difference is very small, the pipeline 4 has not taken cathodic protection measures, on the contrary, when the power-on potential is significantly different from the self-corrosion potential, the pipeline 4 has taken cathodic protection measures. Only when the pipeline 4 has taken cathodic protection measures, the cathodic protection effect of the pipeline 4 can be evaluated by the present invention.

[0046] like Figure 1 As shown, the four insulating connecting tubes 5 are recorded as the first insulating connecting tube, the second insulating connecting tube, the third insulating connecting tube and the fourth insulating connecting tube from top to bottom. A multimeter is used to connect the polarization test piece terminal 15, the self-corrosion test piece terminal 18, the saturated copper sulfate reference electrode terminal 19 and the high-purity zinc reference electrode terminal 20 corresponding to the first insulating connecting tube to measure the power-on potential, power-off potential (i.e., polarization potential) and self-corrosion potential of the crossing section pipeline 4 at the depth position of the first insulating connecting tube (specifically, the depth position of the test piece on the first insulating connecting tube), and then determine the cathodic protection effect of the crossing section pipeline 4 at the depth position. Similarly, the power-on potential, power-off potential (i.e., polarization potential) and self-corrosion potential of the crossing section pipeline 4 at the depth position of the second insulating connecting tube, the third insulating connecting tube and the fourth insulating connecting tube can be measured, and then determine the cathodic protection effect of the crossing section pipeline 4 at the above-mentioned depth positions.

[0047] It should be noted that the directions or positional relationships indicated by terms such as “center”, “up”, “down”, “front”, “back”, “left”, “right”, and “middle” are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present invention.

[0048] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] The embodiments described above are merely descriptions of preferred implementation modes of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A device for testing the cathodic protection effect of a directional drilling pipeline, characterized in that: It comprises a test tube and a test box, wherein the test tube comprises a plurality of insulating connecting tubes coaxially connected in sequence along the vertical direction, and a self-corrosion test piece, a high-purity zinc reference electrode, a polarization test piece and a saturated copper sulfate reference electrode are arranged on the outer tube wall of the insulating connecting tube in sequence from top to bottom, and the self-corrosion test piece, the high-purity zinc reference electrode, the polarization test piece and the saturated copper sulfate reference electrode are respectively connected to the test box through a first wire, a second wire, a third wire and a fourth wire, and the first wire, the second wire, the third wire and the fourth wire are all located in the test tube, and the test box is connected to a fifth wire for connecting to a crossing section pipeline.

2. The device for testing the cathodic protection effect of a directional drilling pipeline according to claim 1 is characterized in that: The self-corrosion test piece is connected to one end of a first wire, the other end of the first wire passes through the wall of the insulating connecting tube into the test tube and extends from the upper tube opening of the test tube, the other end of the first wire is connected to a test box, the high-purity zinc reference electrode is connected to one end of a second wire, the other end of the second wire passes through the wall of the insulating connecting tube into the test tube and extends from the upper tube opening of the test tube, the other end of the second wire is connected to a test box, the polarization test piece is connected to one end of a third wire, the other end of the third wire passes through the wall of the insulating connecting tube into the test tube and extends from the upper tube opening of the test tube, the other end of the third wire is connected to a test box, the saturated copper sulfate reference electrode is plugged into the wall of the insulating connecting tube, the two ends of the saturated copper sulfate reference electrode are respectively located on the inner side and the outer side of the insulating connecting tube, the end of the saturated copper sulfate reference electrode located on the inner side of the insulating connecting tube is connected to one end of a fourth wire, the other end of the fourth wire extends from the upper tube opening of the test tube, and the other end of the fourth wire is connected to a test box.

3. The device for testing the cathodic protection effect of a directional drilling pipeline according to claim 2, characterized in that: The outer tube wall of the insulating connecting tube is provided with a first slot, a second slot, a third slot and a through hole in sequence from top to bottom. The first slot, the second slot and the third slot are arranged along the circumference of the insulating connecting tube. The first slot is provided with a first wire hole penetrating the tube wall of the insulating connecting tube, the second slot is provided with a second wire hole penetrating the tube wall of the insulating connecting tube, and the third slot is provided with a third wire hole penetrating the tube wall of the insulating connecting tube. The self-corrosion test piece, the high-purity zinc reference electrode and the polarization test piece are all annular structures. The self-corrosion test piece, the high-purity zinc reference electrode and the polarization test piece are respectively clamped in the first slot, the second slot and the third slot. The other end of the first wire passes through the tube wall of the insulating connecting tube through the first wire hole, the other end of the second wire passes through the tube wall of the insulating connecting tube through the second wire hole, and the other end of the third wire passes through the tube wall of the insulating connecting tube through the third wire hole. The saturated copper sulfate reference electrode is plugged into the through hole.

4. The device for testing the cathodic protection effect of a directional drilling pipeline according to claim 3 is characterized in that: The self-corrosion test piece includes two semi-annular self-corrosion test piece halves, the two self-corrosion test piece halves are relatively clamped in the first clamping slot, the first wire holes are set to two, the two first wire holes are respectively arranged at the positions of the first clamping slot corresponding to the two self-corrosion test piece halves, the first wire includes two first branch wires, one end of the two first branch wires is respectively connected to the two self-corrosion test piece halves, and the other ends of the two first branch wires respectively pass through the two first wire holes into the test tube and merge into the other end of the first wire.

5. The device for testing the cathodic protection effect of a directional drilling pipeline according to claim 4 is characterized in that: The high-purity zinc reference electrode includes two high-purity zinc reference electrode halves, both of which are semi-annular. The two high-purity zinc reference electrode halves are relatively clamped in the second clamping slot. The number of the second wire holes is set to two, and the two second wire holes are respectively arranged at positions of the second clamping slot corresponding to the two high-purity zinc reference electrode halves. The second wire includes two second branch wires, one end of the two second branch wires is respectively connected to the two high-purity zinc reference electrode halves, and the other ends of the two second branch wires respectively pass through the two second wire holes into the test tube and merge into the other end of the second wire.

6. The device for testing the cathodic protection effect of a directional drilling pipeline according to claim 5 is characterized in that: The polarization test strip includes two polarization test strip halves, both of which are semi-annular, and the two polarization test strip halves are relatively clamped in the third clamping slot. The third wire holes are provided with two, and the two third wire holes are respectively provided at positions of the third clamping slot corresponding to the two polarization test strip halves. The third wire includes two third branch wires, and one ends of the two third branch wires are respectively connected to the two polarization test strip halves, and the other ends of the two third branch wires respectively pass through the two third wire holes to enter the test tube and merge into the other end of the third wire.

7. The device for testing the cathodic protection effect of a directional drilling pipeline according to claim 6 is characterized in that: The two adjacent insulating connecting tubes are an upper insulating connecting tube and a lower insulating connecting tube, respectively. The upper insulating connecting tube is located above the lower insulating connecting tube, the lower end of the upper insulating connecting tube is provided with an internal thread, and the upper end of the lower insulating connecting tube is provided with an external thread. The upper insulating connecting tube and the lower insulating connecting tube are connected by the internal thread and the external thread.

8. The device for testing the cathodic protection effect of a directional drilling pipeline according to any one of claims 1 to 7, characterized in that: The test box is provided with an insulating plate, on which are provided self-corrosion test piece terminals, high-purity zinc reference electrode terminals, polarization test piece terminals, saturated copper sulfate reference electrode terminals and pipeline terminals. The self-corrosion test piece terminals, high-purity zinc reference electrode terminals, polarization test piece terminals and saturated copper sulfate reference electrode terminals are all provided in plurality, and a plurality of insulating connecting pipes, a plurality of self-corrosion test piece terminals, a plurality of high-purity zinc reference electrode terminals, a plurality of polarization test piece terminals and a plurality of saturated copper sulfate reference electrode terminals are arranged in one-to-one correspondence. The self-corrosion test piece on the insulating connecting pipe is connected to the insulating pipe through a first wire. The insulating connecting tube is connected to the self-corrosion test piece terminal corresponding to the insulating connecting tube, the high-purity zinc reference electrode on the insulating connecting tube is connected to the high-purity zinc reference electrode terminal corresponding to the insulating connecting tube through a second wire, the polarization test piece on the insulating connecting tube is connected to the polarization test piece terminal corresponding to the insulating connecting tube through a third wire, the saturated copper sulfate reference electrode on the insulating connecting tube is connected to the saturated copper sulfate reference electrode terminal corresponding to the insulating connecting tube through a fourth wire, and multiple polarization test piece terminals are respectively connected to the pipeline terminals through control switches, and the pipeline terminals are connected to a fifth wire for connecting to the crossing section pipeline.

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