Prediction method for extension track of hydrofracture complex fracture of conglomerate reservoir

Abstract

The invention discloses a conglomerate reservoir hydrofracture complex fracture extension trajectory prediction method, which comprises the following steps: generating a square servo boundary, and randomly generating a matrix particle model in the servo boundary; generating a gravel profile in the matrix particle model; defining the matrix in the gravel contour as a gravel particle cluster, and respectively assigning the mesomechanics parameters of matrix particles and gravel particles; gravel edge contact on the gravel contour is obtained by writing a traversal function; establishing a pipe domain seepage model, carrying out fluid-solid coupling, giving an injection rate, and establishing a crack extension criterion; gravels with different cementation strengths and crack extension tracks under the gravel edges with different cementation strengths are simulated by changing microscopic mechanical parameters of gravel particles and gravel edges. The method has the following beneficial effects that complex geometrical shapes and irregular outlines of gravels and different cementing strengths of gravel edges are fully considered, and the process of generating complex cracks when hydrofracture cracks meet the gravels can be further known.

Description

technical field [0001] The invention relates to a method for predicting the extension trajectory of complex fractures of conglomerate reservoir hydraulic fracturing, and belongs to the field of oil and gas field stimulation and reconstruction. Background technique [0002] Conglomerate reservoirs generally have the characteristics of low porosity, low permeability and strong heterogeneity. At present, hydraulic fracturing has become the main measure for stimulation and stimulation of tight conglomerate reservoirs. [0003] The pore structure of conglomerate reservoirs is relatively complex, with strong heterogeneity and obvious anisotropy, and gravel particles have a great influence on the fracture extension process. Impact. Conglomerate is mainly composed of gravel, matrix and gravel edge, among which the gravel is mostly angular or sub-angular, mainly irregular polygons. The current method of hydraulic fracturing fracture extension of conglomerate reservoirs does not full...

AI Technical Summary

Problems solved by technology

Conglomerate is mainly composed of gravel, matrix and gravel edges. The gravel is mostly angular or sub-angular, mainly irregular polygonal. The current fracture extension method for hydraulic fracturing of conglomerate reservoirs does not fully consider the complex geometry and shape of the gravel. The irregular contour does not consider the influence of different cementation strengths between the gravel and the matrix, that is, the gravel edge, on the fracture extension, resulting in the analysis of the fractures that appear during the hydraulic fracturing fracture extension process around the gravel, through the gravel, stop at the gravel, and meet the gravel. Forking Multiple Phenomena Lack of Prediction and Explanation

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