A volumetric fracturing method for atmospheric shale gas with horizontal wellbore passing through multiple layers

Abstract

The invention discloses an atmospheric shale gas volume fracturing method using a horizontal wellbore which bores through multiple layers. The method comprises the steps of (1) reservoir evaluation before fracturing; (2) fracture three-dimensional extension scale simulation and analysis; (3) hydraulic jetting perforating parameter designing, wherein hydraulic nozzles are distributed in the same plane, fractures with no special requirements on upward extension or downward extension are evenly distributed at the same plane, and for fractures which need to excessively extend upwards or downwards,an uneven hole arrangement mode is adopted in the upper semi-circumference position or the lower semi-circumference position on the cross section of a hydraulic jetting pipe string; (4) injection mode designing, wherein a high-viscosity glue solution is adopted for the injection mode, and a pre-injection mode is conducted while matched with the designed maximum delivery; (5) variable-density supporting agent optimization; (6) real-time improvement of construction parameter designing and adjustment of the main fracture net pressure. By means of the method, the yield-increasing potential of a shale gas reservoir is tapped to the utmost extent, and the success rate of fracturing is improved; the requirements of volume fracturing of the shale oil and gas reservoir are met, and the method is beneficial to application and popularization of a hydraulic fracturing technology.

Description

technical field [0001] The invention relates to the technical field of oil and gas field exploration and development, and more particularly relates to a method for shale gas volume fracturing at normal pressure in which a horizontal wellbore passes through multiple layers. Background technique [0002] In normal pressure shale gas drilling, especially in horizontal wellbore drilling, although the target layer is a definite shale gas layer, such as the No. Due to the lack of data, sometimes the wellbore deviates from the target layer, and after discovery, it is transferred back to the original target layer. Or, sometimes due to fear of drilling a fixed shale gas formation, the fracture height will be limited within a certain range, and sometimes multiple shale gas formations are consciously drilled. In other words, it often happens that a horizontal wellbore runs through multiple shale gas formations. For shale gas fracturing in which the horizontal wellbore trajectory cros...

AI Technical Summary

Problems solved by technology

[0007] In order to solve the problem in the prior art that there is no targeted fracturing technology and solution for shale gas fracturing in which the horizontal wellbore trajectory crosses multiple layers, the present invention proposes a normal-pressure shale gas volume pressure in which the horizontal wellbore traverses multiple layers. The fracturing method, the new technology of atmospheric pressure shale gas volume fracturing can maximize the potential of shale gas reservoirs to increase production and improve the success rate of fracturing

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