Self-expanding subsidizing device for oil well casing and subsidizing method thereof

An oil well casing and self-expanding technology, which is applied in the direction of earthwork drilling, wellbore/well components, etc., can solve the problems of short subsidy section, casing deformation, high construction risk, etc., and achieve enhanced resistance to internal pressure and external extrusion Excellent performance, reliable sealing and plugging, and strong corrosion resistance

Active Publication Date: 2018-08-14
PETROCHINA CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantages of this method are: (1) When the hydraulic expansion cone expands and moves, its force point must be fixed on the inner wall of the casing, and the anchor fluke will cause new damage to the casing
(2) The hydraulic cold extrusion expansion device is relatively complicated, and it is prone to jamming during construction. It cannot be pulled out, and it cannot continue to expand and move forward, causing underground accidents
(3) The process is complicated, the cost is high, the subsidy period is short, and the construction risk is high
The disadvantages of this method are (1) The energy generated by the explosion is difficult to control, if it is too small, the purpose of subsidy cannot be achieved, and if it is too large, the casing will be deformed or damaged
(2) Fires in oil wells are very dangerous. Once associated gas exists, major safety accidents such as oil well fires are likely to occur

Method used

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  • Self-expanding subsidizing device for oil well casing and subsidizing method thereof
  • Self-expanding subsidizing device for oil well casing and subsidizing method thereof
  • Self-expanding subsidizing device for oil well casing and subsidizing method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] This embodiment provides an oil well casing self-expanding subsidy device, combined with figure 1 , figure 2 with image 3 As shown, it includes a downhole tool release device and a subsidy pipe, and the subsidy pipe is a memory alloy pipe 1, such as image 3 As shown, the downhole tool release device is composed of a cable 4, a centralizing cylinder 5, a conical limit cylinder 6, and a pressure gauge 7. The pressure gauge 7 is located on the ground, and the pressure gauge 7 is connected to the upper end of the centralizing cylinder 5 through the cable 4. , the lower end of the centralizing cylinder 5 is connected with a tapered spacer cylinder 6 with a small upper end and a large lower end.

[0025] In the structure of this embodiment, the downhole tool release device is used to lower the supplementary pipe to the casing damage position, and the subsidy pipe is heated by the temperature in the well. When the memory alloy pipe reaches the training temperature, it wil...

Embodiment 2

[0027] In the above-mentioned embodiment 1, the memory alloy tube 1 needs to be seated on the tapered limiting cylinder 6 at the beginning to leave the tapered limiting cylinder 6 later. To complete these actions, a special design is required. In this embodiment Described in detail, in this embodiment, the inner diameter of the memory alloy tube 1 is between the inner diameter of the centralizing cylinder 5 and the inner diameter of the lower end of the conical limit cylinder 6. At the beginning, the memory alloy tube 1 is set on the outer seat of the centralizing cylinder 5. On the conical limiting cylinder 6, when entering the well, as the temperature rises, the memory alloy tube 1 expands, and its inner diameter will gradually be greater than the inner diameter of the lowermost end of the conical limiting cylinder 6. At this time, the memory alloy tube 1 will no longer Seat on the conical limiting cylinder 6, it will stick to the casing wall to subsidize the damaged part, an...

Embodiment 3

[0032] This embodiment provides a subsidy method for the aforementioned oil well casing self-expanding subsidy device, combining figure 1 shown, including the following steps:

[0033] Before entering the well, first coat the high temperature resistant adhesive 3 on the outer wall of the rubber sealing ring 2 and the shape memory alloy tube 1, then pass the shape memory alloy tube 1 through the cable 4 and put it on the outside of the centralizing cylinder 5, and its lower end is against the On the middle part of the conical limit cylinder 6;

[0034] Drive the cable 4 through the workover vehicle to lower the subsidy pipe to the casing damage position, let it stand for 30 minutes, and observe the change of the pressure gauge 7;

[0035] When the subsidized pipe is slowly heated by the temperature in the well to reach the training temperature, the subsidized pipe will rapidly self-expand and be firmly attached to the inner wall of the casing, so as to achieve the purpose of r...

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PUM

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Abstract

The invention discloses a self-expanding patching device and method for an oil well casing. The method comprises the following steps: taking a memory alloy pipe of which the outer diameter is smaller than the inner diameter of the casing as a patching pipe substrate; fixing a rubber seal ring on the outer wall of the memory alloy pipe via a temperature-resistant adhesive, so as to obtain a patching pipe; lowering the patching pipe to the damaged position of the casing with an underground tool releasing device; heating the patching pipe with temperature in a well, so that the memory alloy pipe expands fast when temperature of the memory alloy pipe reaches a training temperature, and is tightly patched to the inner wall of the casing, that is, the casing pipe is repaired, wherein the training temperature depends on the damaged position of the casing. As the patching pipe deforms in one direction, the sealing and the blocking are reliable, the strength is high, and the internal pressure resistance and the external collapse resistance of the damaged casing can be improved obviously after the casing is repaired. Moreover, as the patching pipe has a self-expanding property at a set temperature, the casing can be repaired without taking measures such as hydraulic expansion or gunpowder explosion. Therefore, the operation is convenient, the construction is safe, the flaking off possibility is low, and the service life is long.

Description

technical field [0001] The invention belongs to the technical field of casing damaged well treatment in oil fields, and in particular relates to an oil well casing self-expanding subsidy device and a subsidy method thereof. Background technique [0002] With the prolongation of oilfield development time, casing damage of oil and water wells is becoming more and more serious. At present, the most commonly used casing subsidy method at home and abroad is the expansion pipe subsidy method. For example, "a hydraulic variable diameter casing expansion method and its equipment" (CN 1807830A). The method of cone cold extrusion and expansion causes plastic deformation of the steel pipe, subsidizes the inner wall of the damaged casing, and closely adheres to the damaged casing to form a double-layer casing, restore the integrity of the casing, and achieve the purpose of repairing the casing. The subsidy materials used mainly include seamless steel pipes and ERW longitudinal welded ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): E21B29/10
CPCE21B29/10
Inventor 奚运涛李琼玮何治武孙雨来张鑫柱程碧海杨会丽张振云李美玉刘锐
Owner PETROCHINA CO LTD
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