Two-channel injection multi-stage packer staged fracturing string and its application method

Abstract

The invention discloses a staged fracturing string of a dual-channel injection multistage packer and a method for using the same. The fracturing string includes an upper oil pipe and a lower oil pipe, and the lower oil pipe is provided with multiple sets of packers and fracturing sliding sleeves for forming multi-stage layer fracturing. The upper oil pipe and the lower oil pipe pass through The differential sliding sleeve is axially connected together; the differential pressure sliding sleeve is mainly composed of a central tube and an outer cylinder, and a circulation hole is opened on the peripheral wall of the central tube, the upper part of the central tube is connected with the upper oil pipe through the upper joint, and the lower part The lower joint is connected with the lower oil pipe, and the outer cylinder is set on the central pipe through a shear pin and a sealing rubber ring to block the circulation hole of the central pipe. In this way, it can achieve large displacement injection without increasing the pressure level of wellhead equipment and fracturing operations, and retains the drainage of small tubing, which is economical, reliable and practical.

Description

technical field [0001] The invention relates to a fracturing pipe string, in particular to a staged fracturing pipe string injected into a multi-stage packer with two channels, and a method for using the fracturing pipe string. Background technique [0002] Hydraulic fracturing is an important technical measure for increasing production of oil and gas wells and increasing injection of water wells. It injects high-viscosity liquid into the well with a displacement that greatly exceeds the absorption capacity of the formation through the surface high-pressure pump group, and forms cracks in the formation after the pressure near the bottom of the well exceeds the stress near the well wall and the tensile strength of the rock; As the fluid with proppant is injected into the fracture, the fracture gradually extends forward. In this way, sand-filled fractures of sufficient length, certain width and height are formed in the formation, so that oil and gas can flow into the well smo...

AI Technical Summary

Problems solved by technology

When this kind of fracturing string is equipped with a certain pressure level at the wellhead, it is limited by the size of the tubing, and the liquid displacement injected during construction is limited, so it is difficult to achieve good volume stimulation for oil and gas wells

If you want to increase the liquid injection displacement of fracturing construction, you must either increase the pressure level of the wellhead device and fracturing construction, or increase the inner diameter of the tubing; the former technical measures will lead to a substantial increase in production costs; the latter technical measures on the one hand Limited by the size of the casing, increasing the inner diameter of the oil pipe to reduce the drag of the liquid to increase the displacement of the liquid injection is limited. On the other hand, it will not only increase the production cost, but also not conducive to the liquid discharge after pressing.

These will affect the development benefits of oil and gas wells

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