Fracturing method for shallow layer dense oil reservoir horizontal seam

Abstract

The invention relates to a fracturing method for a shallow layer dense oil reservoir horizontal seam, and belongs to the technical field of oil-gas well fracturing yield increase. The fracturing method comprises the following steps that a main seam is opened and expanded; micro-seams are opened and expanded; the micro-seams are filled; seam ends are plugged; when the net pressure is larger than the difference between the maximum stress and the minimum stress, branch seams are opened and expanded; the branch seams are filled; the main seam is filled; and displacement operation is conducted, andfracturing of the horizontal seam is completed. According to the method, the micro-seams are formed in the main seam of the horizontal seam, the micro-seams are expanded and filled, and the seam endsare plugged, so that the branch seams are formed, then the branch seams and the main seam are filled, and fracturing of the horizontal seam is completed; and through fracturing of the horizontal seam, complex seams such as a vertical seam or a T-shaped seam are formed on the basis of the horizontal seam, so that the effective transformation size is increased, a reservoir is fully transformed, thelongitudinal and planar reserve utilization degree of an oil layer of a shallow layer dense oil reservoir is improved, and the oil yield of an oil well is increased.

Description

technical field [0001] The invention relates to a fracturing method for horizontal fractures of shallow tight oil reservoirs, and belongs to the technical field of fracturing and stimulation of oil and gas wells. Background technique [0002] The fracturing process is an important technology for increasing production, increasing injection and maintaining stable production of oil fields. The existing fracturing methods generally adopt three stages for fracturing: pre-fluid stage, sand-carrying fluid stage, and displacement stage. In the pre-fluid stage, the performance of the liquid to transmit pressure is used, and a high-pressure pump group is used on the ground to pump a liquid with a certain viscosity into the well with a displacement greater than the absorption capacity of the formation, and a high pressure is generated at the bottom of the well. This pressure exceeds the in-situ stress of the oil layer and The tensile strength of the rock is to generate cracks in the fo...

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Problems solved by technology

[0004] However, for shallow tight oil reservoirs, due to the shallow burial of the reservoir (less than 650m), fracturing forms horizontal fractures. Although the existing fracturing methods can improve the recovery of the reservoir to a certain extent, the The vertical and horizontal production degree of the horizontal fractures is low, and the reservoir stimulation is insufficient, resulting in poor development effect and affecting the recovery rate. Therefore, it is necessary to propose a plan for fracturing horizontal fractures in shallow tight reservoirs.

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