Modeling method for compact sandstone reservoir three-dimensional fracability model

Abstract

The invention relates to a modeling method for a compact sandstone reservoir three-dimensional fracability model. The method comprises the following steps: S1, establishing a relation formula among an internal friction angle, I type and II type crack fracture toughness and the parameter of sandstone mechanical characteristics; S2, establishing a shale fracability evaluation model which comprehensively considers an elastic parameter, the internal friction angle, the critical strain energy release rate and fracture toughness; S3, adopting a support vector machine algorithm to obtain a cluster analysis mode between the reservoir fracability and the elastic parameter; S4, adopting the cluster analysis mode to obtain a reservoir three-dimensional elastic parameter data body, and establishing the multi-scale compact sandstone reservoir three-dimensional fracability evaluation model based on the core, the borehole and the reservoir of multiple scales. According to the method, the fracability of an arbitrary space position in the compact sandstone reservoir can be obtained, a sweet spot with high fracability can always be drilled when drilling a compact sandstone gas well, blindness of well location selection is avoided, and the fracture modification effect and the yield after fracture are improved.

Description

technical field [0001] The invention belongs to the technical field of tight sandstone oil and gas development, in particular to a modeling method for a three-dimensional fracturing model of tight sandstone reservoirs. Background technique [0002] my country has huge reserves of tight sandstone oil and gas reservoirs. In tight sandstone reservoirs such as Sugeli Gas Field and Xuwu in western Sichuan, the method of horizontal well staged volumetric fracturing has been used to achieve commercial production. Compared with foreign countries, tight sandstone reservoirs in my country have poor physical properties, extremely low porosity and permeability, tight reservoirs, complex lithology, and alternate mixed beds of sandstone and mudstone. Due to the great differences in the internal physical properties and heterogeneity of tight sandstone reservoirs in my country, and the wellbore trajectory design mainly focuses on drilling sweet spots, and the geological sweet spot is not ne...

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Problems solved by technology

[0004] The existing brittleness and fracturing evaluation methods can only provide the brittleness evaluation of the reservoir at the drilling position, but cannot provide the brittleness evaluation of the entire three-dimensional reservoir. better location, a 3D fracability model of the entire reservoir must be established

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