A bushing centering locator and its working method

Abstract

The invention discloses an oil well casing pipe centered locator and a working method thereof. The casing pipe centered locator comprises a casing pipe body and a wing plate control system, and the wing plate control system is composed of a hydraulic locking mechanism, a wing plate driving device and righting wing plates. Self-protection design is adopted for the oil well casing pipe centered locator, hydraulic control are adopted for wing plate unfolding modes, liquid pressure in a casing pipe acts to trigger the wing plate driving device, the wing plates are driven to be unfolded, and the casing pipe is located in an oil well stably and accurately. The casing pipe centered locator is provided with a self-locking mechanism, when pressure in the casing pipe is released, the locking mechanism seals a liquid channel due to the action of the pressure, the wing plates are prevented from drawing back, and a continuous and stable well cementation effect is achieved. According to the oil well casing pipe centered locator, radian design is adopted by the appearance of the righting wing plates, the process that the oil well casing pipe centered locator and the casing pipe are placed in the well together cannot be blocked, downhole accidents cannot occur, the stability and acting force of well cementation are improved to a large extent, and the quality of the well cementation and the oil extraction rate are improved accordingly.

Description

Technical field [0001] The invention relates to a well completion device in the petroleum industry, belonging to the technical field of downhole tools for oil exploitation, in particular to a casing centering locator used in the oil well completion process and a working method thereof. Background technique [0002] At present, the oilfield has entered the stage of fine development. The injection and production of subdivision layers requires high cementing quality. In the process of casing running after oil drilling and completion, the casing needs to be positioned so that the casing is located in the center of the oil well. The casing centering degree will seriously affect the cementing quality. The better the casing centering degree, the higher the cementing displacement efficiency. Especially in horizontal and directional wells, the casing is deviated from the oil well due to the inclined or horizontal state of the casing. The center affects the cementing quality. After perfora...

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Problems solved by technology

[0002] At present, the oilfield has entered the stage of fine development, and injection and production of subdivided layers require high cementing quality. In the process of running casing after oil drilling and completion, the casing needs to be positioned so that the casing is located in the center of the oil well. The casing centering degree will seriously affect the cementing quality. The better the casing centering degree, the higher the cementing displacement efficiency, especially in horizontal wells and directional wells. Because the casing is in an inclined or horizontal state, the casing deviates from the position of the oil well. center, which affects the quality of cementing. After perforating, some channels are easily blocked by sediment and other substances, which affects oil recovery.

[0003] At present, the oil field usually uses elastic centralizers and straight-edged rigid centralizers for cross use. The outer diameters of the elastic centralizers and rigid centralizers used now are fixed, which are equal to or larger than the diameter of the open hole. The process of casing running in horizontal wells and directional wells is easy to be blocked and difficult to run in, which affects the cementing construction and is prone to downhole accidents

Moreover, since the centralizing force of the elastic centralizer is too small, the diameter and area of ​​the water chestnut of the rigid centralizer are small, so the centralizing effect of the two is poor

Due to its own weight and the bending of the wellbore, the casing string will be close to the well wall on one side, which affects the displacement environment of cement and mud, and cannot achieve the displacement effect of flat flow, which affects the cementing quality

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