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CN-122016626-A - Corrosion monitoring device and method for outer wall of underground oil and gas pipeline

CN122016626ACN 122016626 ACN122016626 ACN 122016626ACN-122016626-A

Abstract

The invention provides a corrosion monitoring device and a monitoring method for the outer wall of an underground oil and gas pipeline. When the corrosion hanging piece is detached, the cover plate is detached, and the corrosion hanging piece is pushed out through the through groove on the panel. The hanger plate assembly is used for being inserted into the embedded groove of the outer sleeve, and the corrosion hanger plate is contacted with the outside through the exposed groove. The lining rod of the connecting cover assembly is used for being inserted into the residual space of the imbedding groove so as to limit the inward radial movement of the hanging piece assembly along the outer sleeve. The end face of the sealing cover of the connecting cover assembly is attached to the end face of the outer sleeve, which is arranged in the groove, so that the opening in the groove is sealed, and drilling fluid is prevented from entering the groove to cause corrosion. The corrosion monitoring device for the outer wall of the underground oil gas pipeline can be directly sleeved outside an oil pipe for installation, the hanging piece assembly, the outer sleeve and the connecting cover assembly are simple and convenient to install, and the gaps are sealed, so that corrosion of the contact surface can be prevented, and the device is convenient to detach.

Inventors

  • XING XIJIN
  • LI ZHENBO
  • XING XUESONG
  • YAN WEI
  • FENG HUANZHI
  • ZHANG TAO

Assignees

  • 中海石油(中国)有限公司
  • 中海石油（中国）有限公司北京研究中心

Dates

Publication Date
20260512
Application Date
20260326

Claims (10)

  1. 1. A corrosion monitoring device for an outer wall of an underground oil and gas pipeline, comprising: A hanger assembly comprising a panel (110) and at least one set of corrosion hangers (120) and a cover plate (130) disposed in combination, each set of the corrosion hangers (120) and the cover plate (130) being disposed on opposite sides of the panel (110), the cover plate (130) being removably connected to the panel (110), the corrosion hangers (120) being bonded to the panel (110), a gap between the corrosion hangers (120) and the panel (110) and a gap between the cover plate (130) and the panel (110) being sealed, a through slot (112) being disposed through opposite sides of the panel (110) at a location corresponding to the corrosion hangers (110); The outer sleeve (200), the terminal surface of the first end of outer sleeve (200) is provided with at least one and inserts groove (210), when the quantity of inserting groove (210) is greater than or equal to two, insert groove (210) along the circumference of outer sleeve (200), insert groove (210) along the axial extension of outer sleeve (200), insert groove (210) are used for the string piece subassembly to insert, the outside face of outer sleeve (200) is provided with exposure groove (220) with the corresponding position of corrosion string piece (120), exposure groove (220) are along the radial intercommunication of outer sleeve (200) the inside and outside both sides of inserting groove (210), corrosion string piece (120) are located in exposure groove (220), and the side that corrosion string piece (120) kept away from panel (110) is parallel and level with the outside face of outer sleeve (200), the gap between corrosion string piece (120) and exposure groove (220); Connect lid subassembly, including sealed lid (310) and lining pole (320), lining pole (320) with a plurality of put into groove (210) one-to-one, and with the terminal surface of sealed lid (310) is connected, lining pole (320) are inserted in the surplus space of putting into groove (210), just lining pole (320) extrusion is in put into the medial surface of groove (210) with between the string piece subassembly, sealed lid (310) with outer sleeve (200) can dismantle and be connected, works as sealed lid (310) with outer sleeve (200) are connected, sealed lid (310) are sealed put into groove (210).
  2. 2. The device for monitoring corrosion of an outer wall of a downhole oil and gas pipeline according to claim 1, wherein a first mounting groove (111) is provided at a position where the panel (110) is connected with the cover plate (130), and the thickness of the cover plate (130) is smaller than or equal to the depth of the first mounting groove (111).
  3. 3. A corrosion monitoring device for an outer wall of a downhole oil and gas pipeline according to claim 1, wherein a second mounting groove is provided at a position where the panel (110) is connected with the corrosion tab (120), and a side of the corrosion tab (120) connected with the panel (110) enters the second mounting groove.
  4. 4. The apparatus of claim 1, wherein the corrosion coupon (120) and the exposure groove (220) are rectangular in shape in both a first cross-section that passes through the axis of the outer sleeve (200) and a second cross-section that is perpendicular to the axis of the outer sleeve (200).
  5. 5. The downhole oil and gas pipe outer wall corrosion monitoring device according to claim 1, wherein the third cross-section of the corrosion tab (120) and the exposure groove (220) are each trapezoidal, the fourth cross-section of the corrosion tab (120) and the exposure groove (220) are each rectangular, the third cross-section passes through the axis of the outer sleeve (200), and the fourth cross-section is perpendicular to the axis of the outer sleeve (200).
  6. 6. The apparatus of claim 1, wherein the fifth cross-section and the sixth cross-section of the corrosion coupon (120) and the exposure groove (220) are each trapezoidal, the fifth cross-section passing through the axis of the outer sleeve (200), the sixth cross-section being perpendicular to the axis of the outer sleeve (200).
  7. 7. A corrosion monitoring device for an outer wall of a downhole oil and gas pipeline according to claim 1, wherein the panels (110) are made of polytetrafluoroethylene.
  8. 8. The apparatus of claim 1, further comprising an axial positioning assembly for removable attachment to a tubing and for limiting the axial position of the combination of the outer sleeve (200), the hanger assembly and the connector cap assembly on the tubing.
  9. 9. The device of claim 8, wherein the axial positioning assembly comprises two collar members (400), both collar members (400) being detachably connected to the tubing and located at both ends of the combination of the outer sleeve (200), the hanger assembly and the connector cap assembly.
  10. 10. A method of corrosion monitoring of an outer wall of a downhole oil and gas pipeline, comprising: acquiring the pre-corrosion mass M 0 , the total area A and the density rho of an external leakage surface of a corrosion hanging piece (120) of the corrosion monitoring device of the outer wall of the underground oil and gas pipeline according to any one of claims 1-9 before entering a well; installing a corrosion monitoring device on the outer wall of the underground oil gas pipeline to the outer side of the oil pipe, and putting the corrosion monitoring device into the bottom of the well; acquiring monitoring time T, post-corrosion quality M and pitting corrosion depth I of the corrosion hanging piece (120) after well logging; And calculating an average corrosion rate C and a maximum pitting rate E based on the mass M 0 before corrosion, the total area A of the leakage surface, the density rho, the mass M after corrosion and the pitting depth I so as to analyze the corrosion condition of the underground oil pipe and predict the service life of the oil pipe.

Description

Corrosion monitoring device and method for outer wall of underground oil and gas pipeline Technical Field The invention relates to the technical field of oil and gas well monitoring equipment, in particular to a corrosion monitoring device and a monitoring method for an outer wall of an underground oil and gas pipeline. Background In the oil gas production process, water, hydrogen sulfide, carbon dioxide, bacteria and various salt substances in the oil pipe can cause corrosion problems, if the oil pipe is light, local weightlessness and accumulation of corrosion products are caused, if the oil pipe is heavy, perforation or even breaking of the oil pipe falls into a well, and normal production of an oil gas well is seriously affected. Meanwhile, along with the gradual popularization of unconventional exploitation modes such as carbon dioxide huff and puff oil displacement, the corrosion risks of the outer side of the oil pipe, the technical casing and the oil layer casing are also obviously increased. Casing corrosion can cause formation gas and liquid to enter annulus, so that serious accidents are caused, the service life of an oil gas well is shortened greatly, and great challenges are brought to oil gas development and well repair operation. Therefore, effective monitoring of oil casing corrosion conditions is critical. Currently, corrosion coupon methods are one of the most commonly used corrosion detection means that can determine the type and extent of corrosion by observing the surface topography of the sample and analyzing the corrosion products. However, the existing downhole corrosion monitoring devices have a number of disadvantages in practical applications. The traditional 'shaft hanging ring nipple joint method' needs to adopt a plurality of threaded connection parts, so that the structure is complex, the operation is complex, the influence factors on the corrosion monitoring result are more, and the operation strength is high. In addition, the mounting and the dismounting of the hanging piece are usually completed by cooperation of multiple persons, so that the mounting and the dismounting are difficult and low in efficiency, and great inconvenience is brought to site construction. Disclosure of Invention The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, the invention provides a corrosion monitoring device for the outer wall of an underground oil and gas pipeline, and aims to solve the problems of complex structure, complex operation and high disassembly and assembly difficulty of the underground corrosion monitoring device in the related technology. The invention provides a corrosion monitoring device for an outer wall of an underground oil and gas pipeline, which comprises: a hanger assembly comprising a panel and at least one set of corrosion hangers and a cover plate disposed in combination, each set of the corrosion hangers and the cover plate disposed on opposite sides of the panel, the cover plate being detachably connected to the panel, the corrosion hangers being bonded to the panel, a gap between the corrosion hangers and the panel and a gap between the cover plate and the panel being sealed, the panel being provided with through slots extending through opposite sides of the panel at locations corresponding to the corrosion hangers; The outer sleeve is provided with at least one placement groove on the end face of the first end, when the number of the placement grooves is greater than or equal to two, the placement grooves are distributed along the circumferential direction of the outer sleeve, the placement grooves extend along the axial direction of the outer sleeve, the placement grooves are used for the insertion of the hanging piece assembly, the outer side face of the outer sleeve is provided with exposure grooves corresponding to the corrosion hanging pieces, the exposure grooves are communicated with the inner side and the outer side of the placement grooves along the radial direction of the outer sleeve, the corrosion hanging pieces are positioned in the exposure grooves, the side face, away from the panel, of the corrosion hanging pieces is flush with the outer side face of the outer sleeve, and gaps between the corrosion hanging pieces and the exposure grooves are sealed; the connecting cover assembly comprises a sealing cover and a lining rod, wherein the lining rod is arranged in one-to-one correspondence with a plurality of placing grooves and is connected with the end faces of the sealing cover, the lining rod is inserted into the residual space of the placing grooves, the lining rod is extruded between the inner side faces of the placing grooves and the hanging piece assembly, the sealing cover is detachably connected with the outer sleeve, and when the sealing cover is connected with the outer sleeve, the sealing cover seals the placing grooves. According to the corrosion monitoring device for the outer