Method for improving permeability of broken and soft oil and gas reservoir

Abstract

The invention discloses a method for improving the permeability of a broken and soft oil and gas reservoir and belongs to the field of oil and gas field development. The method comprises the following steps that a vertical well is vertically-downwards dug from the ground to the position of 1-2 meters below the oil and gas reservoir, and a horizontal well is dug in the horizontal direction. Oriented perforating is conducted from an oil and gas reservoir base plate to the overlying oil and gas reservoir through an oriented perforating gun of the horizontal well, and afterwards fracturing fluid is pumped by a high pressure pump for fracturing the oil and gas reservoir. After fracturing, a seepage passage is formed under the supporting effect of a supporting agent on fracturing fractures, and thus the permeability of the oil and gas reservoir is improved. According to the method for improving the permeability of the broken and soft oil and gas reservoir, on the one hand, fracturing of the oil and gas reservoir and expanding of cracks are facilitated, the permeability of the reservoir is improved; and on the other hand, through the fracturing technology of perforating upwards, fractured rock debris is prone to being discharged from fracturing holes under the gravity effect of the rock debris, and thus the problem that direct fracturing and slag returning are difficult in a coal layer is solved. Meanwhile, through the fracturing technology of perforating upwards, the stress from a bottom rock layer to the upper portion oil and gas reservoir is in a progressively- decreasing state, and thus fracturing of the upper portion oil and gas reservoir is facilitated.

Description

technical field [0001] The invention relates to a method for improving the permeability of broken and soft oil and gas reservoirs, which belongs to the field of oil and gas field development, and in particular relates to a method for low permeability oil and gas reservoirs with low permeability, seepage resistance and poor connectivity between pores. , a method for increasing permeability by vertical upward directional perforation technology that is convenient for upward fracturing and crack expansion. [0002] technical background [0003] For low-permeability oil and gas reservoirs, the reservoir fracturing technology is usually used to improve the permeability, thereby increasing oil and gas production. However, the fracturing of oil and gas reservoirs usually faces many technical difficulties. For example, the surface drainage wells are not deep enough to be drilled into the sky; Oil production and gas volume. [0004] At present, it is an excellent method to fracture o...

AI Technical Summary

Problems solved by technology

① When drilling with a hydraulic drilling rig, the low-strength, broken and soft oil and gas reservoirs will collapse when encountering water, causing drill sticking or even drilling accidents

②When using wind power drilling, the system pressure is low and the air volume is unstable, which makes it difficult to discharge powder in deep holes and the drilling cannot be drilled

①Breakage and plugging are prone to occur in the process of negative pressure drainage

[0011] Another example is the publication number of CN201908640U's "a kind of anti-buried horizontal well staged fracturing string", CN202788753U's "pressure differential sliding sleeve for sidetracking horizontal well staged fracturing", and CN204877415U's "a horizontal well segmented Fracturing string" only improves the staged fracturing process of horizontal wells, and does not involve the reservoir permeability enhancement

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