Failure judgment method for nondestructive testing of well drilling steel wire rope

Abstract

The invention discloses a failure judgment method for nondestructive inspection of well drilling steel wire ropes. The failure judgment method specifically comprises the following steps: step 1, calculating metal cross sectional area loss rates of steel wire ropes with and without defect rope samples; 2, sequentially measuring magnetic lines of force of the defect-free rope sample and all defect rope samples, and determining a magnetic line center line signal value of the defect-free rope sample and a peak value of the magnetic line of force of each defect rope sample; 3, calculating a difference value between each magnetic line peak value and the magnetic line midline signal value; 4, the difference value obtained in the step 3 corresponds to the calculated metal cross section area loss rate, obtained in the step 1, of the steel wire rope, and a corresponding table is drawn; and step 5, measuring the to-be-measured service steel wire rope, and judging whether to cut the rope or not according to a measurement result. According to the method, the problems of premature rope cutting and large calculation amount of rope cutting index judgment in the prior art are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of non-destructive flaw detection of steel wire ropes, and in particular relates to a failure determination method for non-destructive flaw detection of drilling steel wire ropes. Background Art

[0002] During the use of drilling wire rope, according to different drilling operation conditions, such as drilling, coring, salvaging, casing, etc., the wire rope will be subjected to impact loads during the lifting and drilling process, friction loads in contact with the drum pulley surface, and alternating loads under the action of the wire rope and complex downhole conditions. Therefore, wear and fatigue wire breakage become the main failure forms of drilling wire rope. In order to ensure the safe production of the petroleum industry, my country's drilling wire rope, the current ton-kilometer cutting standard API 9B "Recommended Practice for the Selection and Maintenance of Wire Ropes for the Petroleum and Natural Gas Industry", gives the wire rope ton-kilometer method for cutting and scrapping, and uses computer programs to cut the drilling wire rope length L and the cutting target ton-kilometer T q As well as the calculation of the cumulative ton-kilometer T of the wire rope for drilling operations, with the development of the wire rope industry in recent years and the widespread application of non-destructive testing technology, the disadvantages of traditional ton-kilometer cutting have gradually emerged, as follows: 1) The basis for scrapping of the cutting rope is unclear. Ton-kilometer is a predictive advance rope cutting. The basis for determining scrapping mainly depends on the cumulative operation volume (ton-kilometer) of the wire rope. For production safety, when the rated operation volume is reached, the wire rope is forcibly cut regardless of whether it reaches the broken wire scrap standard; 2) The calculation error is large. The ton-kilometer calculation formula involves many uncertain factors and requires a large amount of measured data support. Therefore, the cumulative value of ton-kilometers often deviates greatly from the set target value, affecting the safety of drilling wire rope use. Summary of the invention

[0003] The purpose of the present invention is to provide a failure determination method for non-destructive testing of drilling wire ropes, so as to solve the problems of premature rope cutting and large amount of calculation for determining rope cutting index in the prior art.

[0004] The technical solution adopted by the present invention is a failure determination method for non-destructive testing of drilling wire ropes, specifically:

[0005] Step 1, calculating the metal cross-sectional area loss rate of the steel wire rope with defects and without defects;

[0006] Step 2, measuring the magnetic force lines of the defect-free rope sample and all defective rope samples in turn, and determining the center line signal value of the magnetic force line of the defect-free rope sample and the peak value of the magnetic force line of each defective rope sample;

[0007] Step 3, calculating the difference between the peak value of each magnetic line of force and the signal value of the center line of the magnetic line of force;

[0008] Step 4, correspond the difference obtained in step 3 with the calculated metal cross-sectional area loss rate of the wire rope obtained in step 1, and draw a corresponding table;

[0009] Step 5, measuring the service wire rope to be measured, and determining whether to cut the rope according to the measurement result.

[0010] The present invention is also characterized in that:

[0011] The specific process of step 1 is:

[0012] Step 1.1: Number the defective and non-defective wire rope samples

[0013] Defective rope samples include one wire broken in the outer layer of the outer strand of the wire rope, which is recorded as 1; two wires broken in the outer layer of the outer strand of the wire rope, which is recorded as 2; three wires broken in the outer layer of the outer strand of the wire rope, which is recorded as 3; and so on, n wires broken in the outer layer of the outer strand of the wire rope, which is recorded as n; where n is determined by the number of visible broken wires within one lay length of the structure mentioned in GB / T5972;

[0014] The wire rope sample without defects is recorded as 0;

[0015] Step 1.2, calculate the wire rope metal cross-sectional area loss rate of defective and non-defective rope samples, the expression is:

[0016] Ci=i·A / A c , i=0,1,2......n (1)

[0017] Where Ci is the calculated metal cross-sectional area loss rate of the wire rope; A is the nominal metal cross-sectional area of ​​the outer layer of the outer strand of the wire rope; A c Calculate the metal cross-sectional area of ​​the wire rope, which is the sum of the metal cross-sectional areas calculated from the nominal diameter design values ​​of each layer of steel wire in the wire rope;

[0018] in,

[0019] A=π·0.25·d 2 (2)

[0020] Where, d is the nominal diameter of the outer layer of the outer strand of the wire rope;

[0021]

[0022] In the formula, δ m It is the nominal diameter of each layer of steel wire in the wire rope.

[0023] The specific process of step 2 is:

[0024] Step 2.1, using electromagnetic method to measure the magnetic force lines of the defect-free rope sample in step 1, determine the signal value of the center line of the magnetic force lines, recorded as A0, and the center line is used as the reference zero point for failure judgment;

[0025] Step 2.2, use the electromagnetic method to measure the magnetic lines of force of all defective rope samples in turn, and determine the peak value of each magnetic line of force. The peak values ​​of the magnetic lines of force are recorded as A1, A2, A3...An, and the numbers of the peak values ​​of the magnetic lines of force correspond to the numbers of the defective rope samples one by one.

[0026] In step 4, the corresponding table is:

[0027]

[0028] The specific process of step 5 is:

[0029] The electromagnetic method is used to measure the magnetic field lines of the service wire rope to be tested when one wire, two wires, ... n wires are broken, and the peak value of each magnetic field line is obtained respectively, and the maximum peak value B is selected from them. 实 , and calculate the measured metal cross-sectional area loss rate C corresponding to the maximum peak 实 , the peak value accumulated within one lay length of the service wire rope B 累 , the metal cross-sectional area loss rate C of the service wire rope within one lay length 累 , and then determine whether the rope cutting conditions are met;

[0030] If any of the following conditions are met, the rope will be cut:

[0031] Condition 1: B 实 ≥An-A0, or C 实 ≥Cn;

[0032] Condition 2: B 累 ≥An-A0, or C 累 ≥Cn.

[0033] Wire rope metal cross-sectional area loss rate = magnetic force line peak value - magnetic force line center line signal value.

[0034] The beneficial effects of the present invention are as follows: the failure judgment method of the drilling wire rope non-destructive testing of the present invention measures the magnetic force lines of the defective rope sample and the service wire rope by electromagnetic method, determines the peak value of the magnetic force lines and the metal cross-sectional area loss rate of the wire rope, and performs the drilling wire rope cutting operation as required, so that the service life of each wire rope can be fully utilized, which corresponds to the scrapping of the wire rope when the number of visible broken wires reaches in the GB / T 5972 standard, and avoids the waste caused by premature rope cutting. In addition, the method is simple, has a small amount of calculation, is mature in technology, has a high scientific and technological content, and can be promoted and applied. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1Schematic diagram of defective rope sample in failure determination method of nondestructive testing of drilling wire rope. DETAILED DESCRIPTION

[0036] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] Example 1

[0038] The failure determination method of the drilling wire rope nondestructive testing of the present invention is specifically implemented according to the following steps:

[0039] Step 1, calculating the metal cross-sectional area loss rate of the steel wire rope with defects and without defects;

[0040] Step 1.1, numbering the defective wire rope samples and the non-defective wire rope samples;

[0041] like Figure 1 As shown, the defective rope samples include one wire broken in the outer layer of the outer strand of the wire rope, which is marked as 1; two wires broken in the outer layer of the outer strand of the wire rope, which is marked as 2; three wires broken in the outer layer of the outer strand of the wire rope, which is marked as 3; and so on, n wires broken in the outer layer of the outer strand of the wire rope, which is marked as n; wherein n is determined by the number of visible broken wires within one lay length of the structure mentioned in GB / T 5972;

[0042] The wire rope sample without defects is recorded as 0;

[0043] Step 1.2, calculate the metal cross-sectional area loss rate Ci of the wire rope of the defective rope sample and the non-defective rope sample in step 1, the expression is:

[0044] Ci=i·A / A c ,i=0,1,2......n (1)

[0045] Where Ci is the calculated metal cross-sectional area loss rate of the wire rope; A is the nominal metal cross-sectional area of ​​the outer layer of the outer strand of the wire rope; A c Calculate the metal cross-sectional area of ​​the wire rope, which is the sum of the metal cross-sectional areas calculated from the nominal diameter design values ​​of each layer of steel wire in the wire rope;

[0046] in,

[0047] A=π·0.25·d 2 (2)

[0048] Where, d is the nominal diameter of the outer layer of the outer strand of the wire rope;

[0049]

[0050] In the formula, δ m It is the nominal diameter of each layer of steel wire in the wire rope;

[0051] Step 2, using electromagnetic method to measure the magnetic force lines of the defect-free rope sample and all defective rope samples in turn, and determine the center line signal value of the magnetic force line of the defect-free rope sample and the peak value of the magnetic force line of each defective rope sample;

[0052] Step 2.1, using electromagnetic method to measure the magnetic force lines of the defect-free rope sample in step 1, determine the signal value of the center line of the magnetic force lines, recorded as A0, and the center line is used as the failure judgment reference zero point, that is, the center line is used as the horizontal coordinate;

[0053] For defect-free rope samples, the dispersion of magnetic lines of force represents the uniformity of the twisting of the wire rope and the smoothness of the rope diameter;

[0054] Step 2.2, using the electromagnetic method to measure the magnetic force lines of all defective rope samples in turn, and determine the peak value of each magnetic force line. The peak values ​​of the magnetic force lines are recorded as A1, A2, A3...An, and the numbers of the peak values ​​of the magnetic force lines correspond to the numbers of the defective rope samples. Specifically, the peak value of the magnetic force line corresponding to the rope sample number 1 is numbered A1, the peak value of the magnetic force line corresponding to the rope sample number 2 is numbered A2, the peak value of the magnetic force line corresponding to the rope sample number 3 is numbered A3, ..., and the peak value of the magnetic force line corresponding to the rope sample number n is numbered An;

[0055] Step 3, respectively calculating the difference between each magnetic force line peak value obtained in step 4 and the magnetic force line centerline signal value obtained in step 3, wherein the difference represents the metal cross-sectional area loss rate of the wire rope at the point in the wire rope;

[0056] Step 4, correspond the difference obtained in step 3 with the metal cross-sectional area loss rate of the wire rope in step 1, and draw a corresponding table;

[0057] Step 5, measuring the service wire rope to be measured, and determining whether to cut the rope according to the measurement result;

[0058] The specific process is:

[0059] The electromagnetic method is used to measure the magnetic field lines of the service wire rope to be tested when one wire, two wires, ... n wires are broken, and the peak value of each magnetic field line is obtained respectively, and the maximum peak value B is selected from them. 实 , and calculate the measured metal cross-sectional area loss rate C corresponding to the maximum peak 实 , the peak value accumulated within one lay length of the service wire rope B 累 , the metal cross-sectional area loss rate C of the service wire rope within one lay length 累 , and then determine whether the rope cutting conditions are met;

[0060] If any of the following conditions are met, the rope will be cut:

[0061] Condition 1: B 实 ≥An-A0, or C 实 ≥Cn;

[0062] Condition 2: B 累 ≥An-A0, or C 累 ≥Cn.

[0063] Example 2

[0064] Based on Example 1, the corresponding tables in step 4 are specifically:

[0065]

[0066] Among them, Cn>....>C2>C1; An-A0>....>A2-A0>A1-A0.

[0067] Example 3

[0068] Take the diameter D26.0mm, structure 6×19S-IWRC, right-hand interlaced wire rope as an example to illustrate;

[0069] According to GB / T 5972 "Maintenance, Maintenance, Inspection and Scrapping of Crane Wire Ropes", within 6d (one lay length), multi-layer winding wire ropes and alternating twisted wire ropes, it can be seen that the number of broken wires in the outer layer is 5, so n=5, the rope samples are numbered 0, 1, 2, 3, 4, 5, and a total of 6 rope samples;

[0070] The metal cross-sectional area loss rates C0 to C5 of the steel wire ropes with defective rope samples 1 to 5 are calculated and obtained by combining formulas (1) to (3):

[0071] C0=0; C1=1.07%; C2=2.14%; C3=3.21%; C4=4.28%; C5=5.36%;

[0072] The electromagnetic method is used to measure the magnetic force lines of the defect-free rope sample No. 0, and the line signal value is determined to be A0 = 2000, which is used as the failure judgment reference zero point;

[0073] The electromagnetic method is used to measure the defective rope samples No. 1 to 5 in sequence, and the peak values ​​of the magnetic lines A1 to A5 are measured.

[0074] The measured data are A1=2400; A2=3000; A3=3800; A4=4800; A5=5500, the horizontal axis is the magnetic force line centerline signal value A0 of rope sample number 0, and the difference between the two represents the metal cross-sectional area loss rate of the wire rope at that point in the wire rope;

[0075] A1-A0=2400-2000=400;

[0076] A2-A0=3000-2000=1000;

[0077] A3-A0=3800-2000=1800;

[0078] A4-A0=4800-2000=2800;

[0079] A5-A0=5500-2000=3500;

[0080] Draw the corresponding table as follows:

[0081]

[0082] Electromagnetic method was used to measure the diameter of the in-service 26.0 mm, structure 6×19S-IWRC, right-hand interlaced wire rope;

[0083] (1) Maximum peak value B 实 =2600,1800<B 实 <2800, the metal cross-sectional area loss rate of the steel wire rope is 3.21%<C 实 <4.28%;

[0084] (2) Peak value accumulated within one lay length of wire rope B 累 =3200<3500, metal cross-sectional area loss rate C within one lay length 累 =4.80%<5.36%;

[0085] From the above, we can see that the wire rope can be used normally without cutting the rope.

Claims

1. A failure determination method for nondestructive testing of drilling wire ropes, characterized in that: Specifically: Step 1, calculating the metal cross-sectional area loss rate of the steel wire rope with defects and without defects; Step 2, measuring the magnetic force lines of the defect-free rope sample and all defective rope samples in turn, and determining the center line signal value of the magnetic force line of the defect-free rope sample and the peak value of the magnetic force line of each defective rope sample; Step 3, calculating the difference between the peak value of each magnetic line of force and the signal value of the center line of the magnetic line of force; Step 4, correspond the difference obtained in step 3 with the calculated metal cross-sectional area loss rate of the wire rope obtained in step 1, and draw a corresponding table; Step 5, measuring the service wire rope to be measured, and determining whether to cut the rope according to the measurement result.

2. The failure determination method for nondestructive testing of drilling wire rope according to claim 1 is characterized in that: The specific process of step 1 is: Step 1.1: Number the defective and non-defective wire rope samples Defective rope samples include one wire broken in the outer layer of the outer strand of the wire rope, which is recorded as 1; two wires broken in the outer layer of the outer strand of the wire rope, which is recorded as 2; three wires broken in the outer layer of the outer strand of the wire rope, which is recorded as 3; and so on, n wires broken in the outer layer of the outer strand of the wire rope, which is recorded as n; where n is determined by the number of visible broken wires within one lay length of the structure mentioned in GB / T5972; The wire rope sample without defects is recorded as 0; Step 1.2, calculate the wire rope metal cross-sectional area loss rate of defective and non-defective rope samples, the expression is: Ci=i·A / A c , i=0,1,2......n (1) Where Ci is the calculated metal cross-sectional area loss rate of the wire rope; A is the nominal metal cross-sectional area of ​​the outer layer of the outer strand of the wire rope; A c Calculate the metal cross-sectional area of ​​the wire rope, which is the sum of the metal cross-sectional areas calculated from the nominal diameter design values ​​of each layer of steel wire in the wire rope; in, A=π·0.25·d 2 (2) Where, d is the nominal diameter of the outer layer of the outer strand of the wire rope; In the formula, δ m It is the nominal diameter of each layer of steel wire in the wire rope.

3. The failure determination method for nondestructive testing of drilling wire rope according to claim 2 is characterized in that: The specific process of step 2 is: Step 2.1, using electromagnetic method to measure the magnetic force lines of the defect-free rope sample in step 1, determine the signal value of the center line of the magnetic force lines, recorded as A0, and the center line is used as the reference zero point for failure judgment; Step 2.2, use the electromagnetic method to measure the magnetic lines of force of all defective rope samples in turn, and determine the peak value of each magnetic line of force. The peak values ​​of the magnetic lines of force are recorded as A1, A2, A3...An, and the numbers of the peak values ​​of the magnetic lines of force correspond to the numbers of the defective rope samples one by one.

4. The failure determination method for nondestructive testing of drilling wire rope according to claim 3 is characterized in that: In step 4, the corresponding table is:

5. The failure determination method for nondestructive testing of drilling wire rope according to claim 4 is characterized in that: The specific process of step 5 is: The electromagnetic method is used to measure the magnetic field lines of the service wire rope to be tested when one wire, two wires, ... n wires are broken, and the peak value of each magnetic field line is obtained respectively, and the maximum peak value B is selected from them. 实 , and calculate the measured metal cross-sectional area loss rate C corresponding to the maximum peak 实 , the peak value accumulated within one lay length of the service wire rope B 累 , the metal cross-sectional area loss rate C of the service wire rope within one lay length 累 , and then determine whether the rope cutting conditions are met; If any of the following conditions are met, the rope will be cut: Condition 1: B 实 ≥An-A0, or C 实 ≥Cn; Condition 2: B 累 ≥An-A0, or C 累 ≥Cn.

6. The failure determination method for nondestructive testing of drilling wire rope according to claim 5, characterized in that: Wire rope metal cross-sectional area loss rate = magnetic force line peak value - magnetic force line center line signal value.

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