Downhole fracturing method

Abstract

The invention provides a downhole fracturing method. The downhole fracturing method comprises the steps that a downhole sand-oil blender is put into a fractured interval through an oil tube to form an oil tube channel; propping agents are injected into the fractured interval through the oil tube channel, and quick water is injected into the fractured interval through an oil jacket annulus channel; and the displacement of high-sand-ratio sand-carrying fluid injected into the fractured interval through the oil tube channel and displacement of quick water injected into the fractured interval through the oil jacket annulus channel are controlled periodically, so that a propping agent bridge is formed in a crack of the fractured interval within a first preset time of one cycle, the propping agent bridge is released within a second preset time of one cycle, and one cycle is the sum of the first preset time and the second preset time. The pressure inside the crack is effectively controlled by periodically controlling the concentration of sand in the crack, the complexity of the crack is improved, the contact area of a hydrocarbon reservoir and the crack is increased, and then the yield is increased under the condition of not polluting the stratum.

Description

technical field [0001] The embodiments of the present invention relate to the technical field of oil recovery engineering, and in particular to a downhole fracturing method. Background technique [0002] The downhole fracturing process is to use the surface high-pressure pump group to inject high-viscosity liquid into the well with a large displacement, and to suffocate high pressure near the bottom of the well. When the pressure exceeds the ground stress and the tensile strength of the rock, fractures are formed in the formation. The fracturing fluid with proppant continues to be injected into the fracture to propel the fracture forward and fill the fracture with proppant. The formed fractures expand oil and gas flow channels and improve formation permeability. [0003] In order to achieve the purpose of increasing production during downhole fracturing, it is usually necessary to form complex fractures, and the key to forming complex fractures is to increase the pressure ...

AI Technical Summary

Problems solved by technology

The method of adding temporary plugging agent to the fracturing fluid has a limited increase in the pressure in the fracture, and the residual temporary plugging agent is easy to cause pollution to the formation

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