Rock core-based fracture continuous-characterization method

Abstract

The invention relates to a rock core-based fracture continuous-characterization method. The measurement accuracy is determined based on actually measured key parameters such as central depth, length, opening degree and filling degree of a rock core fracture as well as a filling material, an angle of inclination and a rock core diameter; a fracture development degree calculation method based on a unit rock core length and related parameters is designed, so that continuous and quantitative characterization can be carried out on fracture development degree, the calculation accuracy of rock core fracture density and a surface fracture rate is improved, and reliable data information guarantee is provided for fracture quantitative prediction. According to the method, the actually measured parameters of the rock core fracture are combined with actual characterization accuracy, so that the distribution situation and concentration degree of the fracture can be continuously represented along a vertical direction, so that the actual demands of exploration and development of oil and gas, especially, fracture type and unconventional exploration and development of the oil and the gas can be met.

Description

technical field [0001] The invention belongs to reservoir fracture characterization technology in oil and gas exploration and development technology, in particular to a continuous fracture characterization method based on rock core. Background technique [0002] As an important storage space and transportation channel for oil and natural gas, fractures play a vital role in both fluid storage and oil and gas migration. Therefore, fracture evaluation, especially in unconventional oil and gas reservoirs with extremely low porosity and permeability, has become an important task in optimizing favorable areas for oil and gas exploration and formulating next-stage development plans. Effective and accurate characterization of fractures is a necessary prerequisite for fracture evaluation. Only by establishing a fracture characterization scheme that can be easily implemented, quantitatively described, and compared vertically and horizontally can it provide correct guidance for later r...

AI Technical Summary

Problems solved by technology

However, the linear density description method has obvious disadvantages: first, the fracture linear density only considers the number of fractures and does not consider the influence of important parameters such as fracture inclination and fracture properties on fracture characterization; second, the unit statistics of fracture linear density The length is usually a certain formation thickness, and the length is longer, resulting in lower calculation accuracy

Therefore, using linear density to characterize fractures in core observation cannot meet the actual needs of high-precision quantitative description for oil and gas exploration.

The description method of fracture surface density (that is, the total length of fractures developed in a unit core area) improves the characterization accuracy to a certain extent, but the measurement of fracture surface density is usually based on a single core for fracture statistics, which is cumbersome to measure and is limited by the core length. 1. The influence of non-geological factors is relatively large, the calculation accuracy is low, and there is no continuity in the vertical direction, and the comparability in the vertical and horizontal directions is poor

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