Compact sandstone reservoir complex netted fracture prediction method

Abstract

The invention belongs to the petroleum exploration field, and concretely relates to a compact sandstone reservoir complex netted fracture prediction method. The method comprises the steps of: building a geological structure model and a fracture growth model; testing magnitudes and directions of ancient and modern crustal stresses; completing a rock mechanic parameter experiment; testing rock mechanic parameters and fracture stress sensitivities; developing a fracture rock multistage composite rupture criterion; performing a rock deformation physical test to obtain a peak value intensity; building a relation model between single axle state stress-strain and fracture bulk density; building a relation model between triaxial state stress-strain and fracture bulk density and occurrence; building a relation model between single axle state stress-strain and fracture bulk density; calculating and stimulating fracture parameters under modern conditions; and verifying the reliability of a fracture quantitative prediction result. The method can accurately obtain compact sandstone reservoir complex netted fracture parameters, and perform quantitative characterization, is suitable for quantitative prediction of any fracture mainly with a brittle reservoir, and reduces exploitation risks and costs.

Description

technical field [0001] The invention belongs to the field of petroleum exploration, and in particular relates to a method for predicting complex network fractures in tight sandstone reservoirs. Background technique [0002] As the exploration and development of oil and gas resources gradually shifts from the east to the west, and from conventional reservoirs to unconventional reservoirs, finding fractured oil and gas reservoirs has become a hot spot. How to predict the spatial distribution of fractures and quantitatively characterize fracture parameters is a key issue in petroleum geology research. frontier issues. Compared with other reservoirs, tight sandstone reservoirs have a large burial depth, high formation pressure coefficient, strong diagenesis, multiple structural movement periods, and well-developed network fractures. Structural fractures are important storage spaces and seepage channels. and development are directly controlled by the tectonic stress field and th...

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Problems solved by technology

Practice has proved that fracture space prediction based on geomechanics theory is an inevitable trend, but there are still defects and deficiencies. Strong heterogeneity of reservoir geological structure, complex and changeable stress conditions, and many periods of tectonic activity all affect the development of fractures. At the same time, the local structure and sedimentary characteristics will also change the redistribution of local stress, so that different groups of fractures overlap and reform each other, and finally form a complex network system; in addition, the fracture origin based on the homogeneous geomechanics model Mechanism analysis only considers the mutual conversion of various elastic energies, ignoring the friction energy consumption and plastic deformation energy of the fracture surface, so it is impossible to establish a more suitable rock composite fracture criterion and a more accurate fracture parameter mechanical model, wasting a lot of time. Computational resources, making fracture modeling and prediction encounter a bottleneck effect

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