Dendritic random fracture network description method for volumetric fracturing of tight reservoirs without natural fractures

Abstract

The present invention relates to a dendritic random fracture network description method for volume fracturing of tight reservoirs without natural fractures, which is specifically as follows: 1. Select rock samples without natural fractures to conduct indoor hydraulic fracturing simulation experiments; 2. The cracks generated on the rock sample are divided into n segments on average from the crack root to the tip, and the fractal dimension Di of each segment is calculated, and the average rotation angle θ between each crack is counted and calculated; 3. Determine the main cracks and secondary cracks; Classify the primary fractures; count the number of secondary fractures at all levels N1j and the total length S1j of the first segment of the fracture closest to the root of the fracture; 4. Given a generator main rod node number M, determine the generator parameters of the fractal L system; 5. 1. Obtain the generator generation formula of the multi-level random tree fracture network; 6. Calculate the fracture length Lf, fracture width and fracture height of the main fracture, and set the fracture width, fracture height and main fracture fracture of all levels of secondary fractures The proportional relationship between width and seam height; 7. Generate three-dimensional tree-shaped seam network graphics. The invention can describe the dendritic random fracture network of the volume fracturing of the tight reservoir without natural fractures.

Description

technical field [0001] The invention relates to the volume fracturing technology of tight reservoirs, in particular to a description method for volume fracturing of tight reservoirs without natural fractures in tree-like random fracture network. Background technique [0002] Due to the characteristics of low porosity and low permeability, tight reservoirs must adopt large-scale volume fracturing technology to achieve industrial development. Volume fracturing technology refers to the application of segmented multi-cluster perforation technology and fracture steering technology, and pumps low-viscosity fracturing fluid with a large displacement to increase the net pressure in the fracture. Reservoir rocks continue to produce shear slip, forcing the formation of primary secondary fractures on both sides of the main fractures, and continue to branch on the basis of primary secondary fractures to form multi-level secondary fractures, so that oil and gas flow from matrix to matrix...

AI Technical Summary

Problems solved by technology

[0009] The object of the present invention is a dendritic random fracture network description method for volume fracturing of tight reservoirs without natural fractures, which is used to solve tight reservoir volume fracturing random fracture network description methods The indescribable problem of the tree-like fracture network in which the main fractures and multi-level random secondary fractures coexist in volume fracturing

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