Oil pipe dragging fracturing pipe column with packer as bottom seal and fracturing method

Abstract

The invention discloses an oil pipe dragging fracturing pipe column with a packer as a bottom seal and a fracturing method. The oil pipe dragging fracturing pipe column comprises a flow guide ball seat, a sand prevention hydraulic anchor, a throttling-free self-service unsetting packer, a hydraulic ejector and a hydraulic safety connector connected to the upper part of the hydraulic ejector through an oil pipe, wherein the flow guide ball seat, the sand prevention hydraulic anchor, the throttling-free self-service unsetting packer and the hydraulic ejector are sequentially connected from bottom to top. The flow guide ball seat comprises a cylindrical body, a valve ball and a baffle ring, wherein the valve ball and the baffle ring are arranged in the cylindrical body from bottom to top; andthe packer comprises a pipe body structure, a sealing mechanism and a power mechanism, wherein the sealing mechanism and the power mechanism sleeve the pipe body from bottom to top, and a compressionspring is arranged in the power mechanism and can move upwards under the hydraulic action to compress the sealing mechanism to form setting. According to the oil pipe dragging fracturing pipe columnwith the packer as the bottom seal and the fracturing method, the tripping-in safety of the fracturing tubular column can be improved, setting and unsetting are achieved through pressure changes in the fracturing tubular column, throttling is not needed, the tripping-in and tripping-out processes of the tubular column are convenient to operate, the fracturing operation efficiency is high, the costis low, the risk is small, and the oil pipe dragging fracturing pipe column can be applied and popularized on vertical wells and horizontal wells.

Description

technical field [0001] The invention relates to the technical field of fracturing operations in oil and gas fields, in particular to an oil pipe dragging fracturing string and a fracturing method with a packer as a bottom seal. Background technique [0002] At present, the tubing-driven fracturing string commonly used in China mainly uses the following two packers as the bottom seal, one is the tubing-driven fracturing string using the K344 packer as the bottom seal, and the other is the Y211 packer The tubing used as the bottom seal drags the fracturing string. [0003] However, in a large number of on-site constructions, these two fracturing strings also have many shortcomings: [0004] (1) If the K344 packer is used as the bottom seal, during the lifting and lowering of the fracturing string, the K344 packer is prone to unnecessary early setting due to pressure fluctuations in the well, resulting in frictional damage and failure of the rubber tube Risks: After each stag...

AI Technical Summary

Problems solved by technology

[0004] (1) If the K344 packer is used as the bottom seal, during the lifting and lowering of the fracturing string, the K344 packer is prone to unnecessary early setting due to pressure fluctuations in the well, resulting in frictional damage and failure of the rubber tube Risks: After each stage of fracturing is completed, the K344 packer expansion rubber tube is automatically unsealed, but the structural characteristics of the rubber sleeve itself determine that the rubber sleeve cannot be completely recovered. In case of sand plugging, incomplete unseal, Sand stuck, causing difficulty in lifting up the pipe string or the risk that the pipe string cannot be pulled out;

[0005] (2) If the Y211 packer is used as the bottom seal, the setting and unsealing operations of the packer need to be carried out by lifting and lowering the fracturing string, which not only requires a high level of operation of the field technicians , and it is easy to block the track change channel of the packer due to the sand settling in the fracturing string, resulting in the difficulty of lifting the fracturing string or the risk that the fracturing string cannot be pulled out, resulting in complex downhole

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