CN111983717A - Accurate positioning method for anchoring part on in-service pipeline - Google Patents
Accurate positioning method for anchoring part on in-service pipeline Download PDFInfo
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- CN111983717A CN111983717A CN202010647531.5A CN202010647531A CN111983717A CN 111983717 A CN111983717 A CN 111983717A CN 202010647531 A CN202010647531 A CN 202010647531A CN 111983717 A CN111983717 A CN 111983717A
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- G01—MEASURING; TESTING
- G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
- G01V11/00—Prospecting or detecting by methods combining techniques covered by two or more of main groups G01V1/00 - G01V9/00
Abstract
The invention discloses a method for accurately positioning an anchoring part on an in-service pipeline, which is realized by the following steps: determining the approximate position of the pipeline by using a pipeline design drawing and later construction data, and further determining the accurate position of the pipeline by a diver; finding the specific position of the anchoring part on the determined pipeline by utilizing ACFM technology; the position of the anchor is further verified. The invention can accurately position the specific position of the anchoring part on the submarine pipeline, and avoids the danger of radiation by a radioactive source during the operation process of constructors.
Description
Technical Field
The invention relates to the field of improvement of submarine pipelines, in particular to a method for accurately positioning an anchoring part on an in-service pipeline.
Background
In order to ensure the pipeline safety of the channel crossing region, the line of the crossing region of the submarine pipeline needs to be changed, the original pipeline of the crossing region is cut and recovered, a hanging line is laid again, and the pipeline burial depth of the crossing region is deepened so as to ensure the safe operation of the pipeline. When cutting the pipeline, in order to prevent water from entering between the inner pipe and the appearance, the cutting is needed from the anchoring part.
The anchoring parts are arranged between the inner layer and the outer layer of the double-layer submarine pipeline at certain intervals, are usually positioned at the welding points of the two submarine pipelines or the flange positions of the submarine pipelines, have the main functions of realizing the movement coupling of the inner pipe and the outer pipe and playing a role in water blocking after water enters the inner pipe and the outer pipe, and are not arranged between every two adjacent submarine pipelines. The anchoring parts are arranged between the inner layer and the outer layer of the double-layer submarine pipeline at certain intervals, are usually positioned at the welding points of two sea pipes or the flange positions of the sea pipes, and have the main functions of realizing the movement coupling of the inner pipe and the outer pipe and playing a role in water blocking after water enters between the inner pipe and the outer pipe. The outer diameter of the anchoring part is completely consistent with that of the sea pipe, only the anticorrosion coating on the surface of the anchoring part welded with the sea pipe is slightly different from the original coating of the sea pipe, but the sea pipe is formed by welding the sea pipes with the length of 12m per section, the surface coating at the welding joint position of the two sea pipes is the same as that of the anchoring part, and meanwhile, the pipeline is buried under the seabed for years, so that a diver is difficult to confirm the pipeline through appearance.
At present, only one ray water-permeable rod piece detection technology of a company can be used for solving the problems, the daily rate and the expense of the moving and reinstalling staff are high due to scarcity, meanwhile, a radioactive source is needed in the operation of the method, certain safety risks exist, the operation staff need to be trained professionally, and the offshore construction needs to be approved by relevant government departments.
As shown in fig. 2 and 3, the anchoring member is divided into an outer pipe and an inner pipe, when the anchoring member is installed, the inner pipe of the anchoring member is clamped with the inner pipe of the marine pipe, and the outer pipe of the anchoring member is welded with the outer pipe of the marine pipe, so that an annular welding seam is formed at the joint of the outer pipe of the anchoring member and the outer pipe of the marine pipe. Two annular welding seams are formed between each anchoring piece and the sea pipe, and the anchoring piece is located between the two adjacent annular welding seams.
Disclosure of Invention
The invention aims to provide an accurate positioning method of an anchor on an in-service pipeline, which can accurately position the position of the anchor on a submarine pipeline, cannot generate radioactive radiation in the implementation process and is safer for constructors.
In order to solve the technical problem, the invention provides a method for accurately positioning an anchoring part on an in-service pipeline, which is realized by the following steps:
s1: determining the initial coordinates of the pipeline, finding out the specific position of the pipeline, and blowing mud to the pipeline;
s2: scanning along the pipeline by using ACFM equipment to find out an annular welding seam between the marine pipe and the anchoring part;
s3: continuously scanning the distance of L2 along the pipeline at the two sides of the annular welding seam by ACFM equipment to find out the next annular welding seam, and if the distance between the two annular welding seams is the length L1 of the anchoring piece, preliminarily determining the position of the anchoring piece between the two annular welding seams; if the next annular welding line cannot be found by using ACFM equipment or the distance between two annular welding lines is not L2 within the range of L2, the anchor is not located, and the ACFM equipment is continuously used for finding the next annular welding line; wherein L2 is greater than L1;
s4: the anchor member found in step S3 and the external marine pipe at both ends of the anchor member are subjected to wall thickness measurement and compared with the initial value, and if the measured value and the initial value match, the position of the anchor member between the two circular welds is finally determined.
Further, step S1 is specifically: according to the initial design scheme and the completion data of the pipeline, determining the initial coordinate of the pipeline, positioning the construction ship on the sea surface at the initial coordinate of the pipeline under the guidance of a positioning system, launching a diver to find the pipeline as a specific position according to the indication of overwater personnel, and blowing mud to the pipeline.
Furthermore, a positioning system used by the construction ship is a DGPS positioning system; the command system used by the personnel on the water is the USBL system.
Further, in steps S2 and S3, at each circumferential weld, a plurality of scans are continued using the ACFM device at different locations along the circumference of the pipeline to eliminate the possibility of pipeline defects.
Further, the method also comprises a step S5 which is arranged after the step S4: and continuously scanning by using the ACFM equipment every 12 meters along the axial direction of the pipeline on two sides of the position of the determined anchor part, positioning the anchor part for the next anchor part, and the like, so that the positions of all the anchor parts on the pipeline can be found.
The invention has the technical effects that:
1. the invention is applied to the field of submarine pipeline reconstruction, can accurately position the position of the anchoring part between submarine pipelines, solves the problem that other methods need a radioactive source in the positioning anchoring part in the operation process, and reduces the safety risk of constructors.
2. The construction equipment is conventional equipment, is safe and reliable, and does not need special approval. The device can be operated repeatedly, and can position a plurality of anchors on the pipeline.
Drawings
FIG. 1 is a perspective view of an anchor according to a preferred embodiment of the present invention;
FIG. 2 is a schematic illustration of the anchor and marine vessel of a preferred embodiment of the present invention after installation;
fig. 3 is a cross-sectional view of the anchor and marine vessel of a preferred embodiment of the present invention after installation.
Reference numerals: an anchor-1; sea pipe-2; a circumferential weld-3; an outer sea pipe-4.
Detailed Description
The present invention is further described with reference to the following drawings and specific examples so that those skilled in the art can better understand the present invention and can practice the present invention, but the examples are not intended to limit the present invention.
Embodiment, as shown in fig. 1 to 3, a method for accurately positioning an anchor 1 on an in-service pipeline is implemented by the following steps:
s1: determining the initial coordinates of the pipeline, finding out the specific position of the pipeline, and blowing mud to the pipeline;
s2: scanning along the pipeline by using ACFM equipment, and finding out an annular welding seam 3 between the marine pipe 2 and the anchoring part 1;
s3: continuously scanning the distance of L2 along the pipeline at the two sides of the annular welding seam 3 by ACFM equipment to find out the next annular welding seam 3, and if the distance between the two annular welding seams 3 is the length L1 of the anchoring piece 1, preliminarily determining the position between the two annular welding seams 3 as the position of the anchoring piece 1; if the next annular welding seam 3 cannot be found by using the ACFM equipment within the range of L2, or the distance between two annular welding seams 3 is not L2, the anchor 1 is not located, and the ACFM equipment is continuously used for finding the next annular welding seam 3; wherein L2 is greater than L1;
s4: the anchor member 1 found in step S3 and the external marine pipe 2 at both ends of the anchor member 1 are subjected to wall thickness measurement and compared with the initial value, and if the measured value and the initial value coincide, the position of the anchor member 1 between the two circular welds 3 is finally determined.
In this embodiment, step S1 specifically includes: according to the initial design scheme and the completion data of the pipeline, determining the initial coordinate of the pipeline, positioning the construction ship on the sea surface at the initial coordinate of the pipeline under the guidance of a positioning system, launching a diver to find the pipeline as a specific position according to the indication of overwater personnel, and blowing mud to the pipeline.
In the embodiment, the positioning system used by the construction ship is a DGPS positioning system; the command system used by the personnel on the water is the USBL system.
In the present embodiment, in steps S2 and S3, at each circumferential weld 3, a plurality of scans are continuously performed at different positions along the circumference of the pipeline using the ACFM equipment, so as to eliminate the possibility of pipeline defects.
In this embodiment, the method further includes step S5 after step S4: and continuously scanning by using the ACFM equipment every 12 meters along the axial direction of the pipeline on two sides of the position of the anchoring piece 1, positioning the anchoring piece 1 for the next anchoring piece, and so on, thereby finding out the positions of all the anchoring pieces 1 on the pipeline.
In this embodiment, the ACFM technology is gradually developed from the alternating current potential difference technology (ACPD). The ACFM detects the defect and crack of a workpiece by utilizing the electromagnetic induction principle, generates a primary magnetic field through a magnetic yoke, generates current on the surface of a metal plate, and detects the change of a secondary magnetic field through a Hall effect sensor. If there are no defects, the alternating current will produce a uniform magnetic field at the surface. If a defect exists on the surface, the defect interferes with the current to change the magnetic field around the defect, and the sensor in the ACFM probe measures the change of the magnetic field to judge the defect. When the ACFM detection technology is researched, the fact that when the material of a scanning area changes or a welding seam in the vertical direction generates a transverse crack-like signal is found, namely, when a crack is vertical to the welding seam direction, current density concentration in the direction vertical to the welding seam is generated, Bx generates a peak, and the direction of current of an X-Y surface in the circumferential direction is opposite. And C, scanning in the direction C, wherein the wave trough appears after the wave crest appears first, scanning in the direction A, and the wave crest appears after the wave trough appears first. ACFM detection detects fracture defects on fine surfaces through non-conductive coatings. The ACFM technology is widely applied to the field of workpiece flaw detection. In the invention, a probe on ACFM equipment scans a pipeline, and when the probe scans the circumferential weld 3 of the marine pipe 2 and the anchoring part 1, a crack image is displayed on the ACFM equipment so as to determine the position of the circumferential weld 3.
It is understood that the present invention is specifically realized by the following steps:
and finding the design position of the anchoring part 1 in the pipe laying construction through the pipe laying layout, combining the completion data, reversely pushing the position of the anchoring part 1 according to the pipe laying route, and combining the two parts to obtain the suspected coordinates of the marine pipe 2 in the area of 30 m. The construction ship is in place on the sea surface at the pipeline initial coordinate position through the DGPS positioning system, a diver wears the underwater USBL, and a surface person utilizes the USBL underwater positioning system to instruct the diver to find the pipeline initial coordinate. After arriving at the initial coordinates of the pipeline, a diver searches for the sea pipe 2 by taking the position as the center, and after finding the sea pipe 2, the diver uses a mud blowing and sucking device to blow and suck mud to the two sides of the pipeline by taking the position as the center, and the two sides of the pipeline are respectively exposed for 15 m.
The diver uses a probe operating on the ACFM equipment to scan along the top of the initially exposed pipeline, with a length L1 of 30cm for anchor 1 and a length L2 of 40cm for each scan.
(1) If ACFM pattern of transverse cracks is found, the pipeline at this position is further blown and sucked to make the pipeline completely exposed. The diver operates the ACFM probe to scan different clock point positions of the position along the circumferential direction of the pipeline, if the ACFM image with transverse cracks appears for many times, the possibility of pipeline defects can be eliminated, and the annular welding seam 3 is confirmed to be the position.
(2) And continuously scanning for 40cm along the axial direction of the pipeline from two sides of the position of the annular welding line 3, if the ACFM graph of the transverse crack at the second position is found at the section, scanning different clock point positions of the position along the circumferential direction of the pipeline by using a probe of ACFM equipment, and repeatedly generating the ACFM graph of the transverse crack, thus eliminating the possibility that the position is a pipeline defect, confirming that the position is the annular welding line 3, measuring that the distance between the two annular welding lines 3 is equal to the length of 30cm of the outer pipe of the anchoring part 1, and confirming that the position is the anchoring part 1.
(3) If the same transverse crack ACFM pattern is not found, the girth weld is a welded joint of two marine pipes 2, or if the distance between the found girth weld 3 and the first found girth weld 3 is not 30cm, this is not the anchor position.
(4) And selecting the middle positions of the two girth welds and the positions of the outer pipes 4 of the marine pipes on the two sides, removing the coatings at the positions of the measuring points, and measuring by using measuring points respectively selected by the underwater ultrasonic thickness gauge. As shown in fig. 2, 5 points, A, B, 1, 2 and 3, are selected on the pipeline and the anchoring member 1 and the outer pipe of the marine pipe on both sides, and the wall thickness of the 5 points is measured and compared with the design value to determine whether the position of the anchoring member 1 is present.
(5) Because each length of the sea pipe 2 is about 12m, the position is the next welding node or the welding position of the anchoring part 1 every 12m from the two sides, and a diver directly scans the position outside the next 12m by using ACFM detection equipment until two annular welding lines with the distance of 30cm are found, and then the position of the next anchoring part 1 can be found.
In the positioning of the anchor 1 once, the following data were obtained:
TABLE-design values for the anchor 1 and the outer marine pipe 4
| Serial number | Length L1 of |
Wall thickness of |
Wall thickness of |
| Design value | 300mm | 80.95mm | 10.3mm |
On-site measured value of table two anchoring part 1
The measured data value obtained by the underwater ultrasonic thickness gauge is compared with the design value to confirm that the position is the position of the anchoring part 1, which further shows that the method is reliable in confirming the position of the anchoring part 1 of the pipeline in service, and the method can quickly and accurately find the position of the anchoring part 1 on the pipeline in service.
The above-mentioned embodiments are merely preferred embodiments for fully illustrating the present invention, and the scope of the present invention is not limited thereto. The equivalent substitution or change made by the technical personnel in the technical field on the basis of the invention is all within the protection scope of the invention. The protection scope of the invention is subject to the claims.
Claims (5)
1. A precise positioning method for an anchoring part on an in-service pipeline is characterized by comprising the following steps: the method is realized by the following steps:
s1: determining the initial coordinates of the pipeline, finding out the specific position of the pipeline, and blowing mud to the pipeline;
s2: scanning along the pipeline by using ACFM equipment to find out an annular welding seam between the marine pipe and the anchoring part;
s3: continuously scanning the distance of L2 along the pipeline at the two sides of the annular welding seam by ACFM equipment to find out the next annular welding seam, and if the distance between the two annular welding seams is the length L1 of the anchoring piece, preliminarily determining the position of the anchoring piece between the two annular welding seams; if the next annular welding line cannot be found by using ACFM equipment or the distance between two annular welding lines is not L2 within the range of L2, the anchor is not located, and the ACFM equipment is continuously used for finding the next annular welding line; wherein L2 is greater than L1;
s4: the anchor member found in step S3 and the external marine pipe at both ends of the anchor member are subjected to wall thickness measurement and compared with the initial value, and if the measured value and the initial value match, the position of the anchor member between the two circular welds is finally determined.
2. The method of claim 1 for precise positioning of an anchor in-service pipeline, wherein: step S1 specifically includes: according to the initial design scheme and the completion data of the pipeline, determining the initial coordinate of the pipeline, positioning the construction ship on the sea surface at the initial coordinate of the pipeline under the guidance of a positioning system, launching a diver to find the pipeline as a specific position according to the indication of overwater personnel, and blowing mud to the pipeline.
3. The method of accurately positioning an anchor in-service pipeline as claimed in claim 2, wherein: the positioning system used by the construction ship is a DGPS positioning system; the command system used by the personnel on the water is the USBL system.
4. The method of claim 1 for precise positioning of an anchor in-service pipeline, wherein: in steps S2 and S3, at each girth weld, multiple scans are continued using the ACFM equipment at different locations along the circumference of the pipeline to eliminate the possibility of pipeline defects.
5. The method of claim 1 for precise positioning of an anchor in-service pipeline, wherein: further includes a step S5 provided after the step S4: and continuously scanning by using the ACFM equipment every 12 meters along the axial direction of the pipeline on two sides of the position of the determined anchor part, positioning the anchor part for the next anchor part, and the like, so that the positions of all the anchor parts on the pipeline can be found.
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| CN202010647531.5A CN111983717A (en) | 2020-07-07 | 2020-07-07 | Accurate positioning method for anchoring part on in-service pipeline |
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| CN202010647531.5A CN111983717A (en) | 2020-07-07 | 2020-07-07 | Accurate positioning method for anchoring part on in-service pipeline |
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Effective date of registration: 20230614 Address after: 100010 No. 25 North Main Street, Dongcheng District, Beijing, Chaoyangmen Applicant after: CHINA NATIONAL OFFSHORE OIL Corp. Applicant after: OFFSHORE OIL ENGINEERING Co.,Ltd. Applicant after: COOEC SUBSEA TECHNOLOGY Co.,Ltd. Address before: 100010 No. 25 North Main Street, Dongcheng District, Beijing, Chaoyangmen Applicant before: CHINA NATIONAL OFFSHORE OIL Corp. Applicant before: OFFSHORE OIL ENGINEERING Co.,Ltd. |
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Address after: 100010 No. 25 North Main Street, Dongcheng District, Beijing, Chaoyangmen Applicant after: CHINA NATIONAL OFFSHORE OIL Corp. Applicant after: OFFSHORE OIL ENGINEERING Co.,Ltd. Applicant after: CNOOC Shenzhen Ocean Engineering Technology Service Co.,Ltd. Address before: 100010 No. 25 North Main Street, Dongcheng District, Beijing, Chaoyangmen Applicant before: CHINA NATIONAL OFFSHORE OIL Corp. Applicant before: OFFSHORE OIL ENGINEERING Co.,Ltd. Applicant before: COOEC SUBSEA TECHNOLOGY Co.,Ltd. |