A Method for Determining Fractability of Formation Based on Tension Fracture and Shear Fracture

Abstract

The invention provides a method for determining the fracturability of formations based on tension fracturing and shear fracturing, and belongs to the field of fracturability evaluation of shale formations in petroleum exploration and development. The invention studies the influence and contribution of tension fracture and shear fracture in the fracturability index of shale formation, and establishes a fracturability index model expressed by the tension fracture and shear fracture models by using logging data. Fracture models and characteristics for formation fracability are comprehensively described. The invention is beneficial for judging the conditions, difficulty and estimation of shear fractures in the formation fracturing process, optimizing the fracturing construction parameters, reducing the exploration and development costs of shale gas formations, and improving the efficiency of shale formations. development efficiency. The quantitative description of the fracturability of shale formations has been realized, which is conducive to formulating perforation and fracturing plans, improving fracturing effects, and increasing shale gas production capacity.

Description

technical field [0001] The invention belongs to the field of fracturing evaluation of shale formations in petroleum exploration and development, and in particular relates to a method for determining the fracturing properties of formations based on tension fracture and shear fracture. Background technique [0002] Whether a shale formation can be fractured depends on two aspects in a broad sense, one is that the shale formation contains relatively rich natural gas, and the other is that the natural gas can be extracted through effective means, that is, a reservoir quality related to the shale formation , and the other relates to the engineering quality of shale formations. [0003] Formation fractures usually include tensile fractures and shear fractures. Tensile fracture is the fracture that occurs when the applied stress exceeds the critical stress intensity factor of the formation when there are cracks or micro-fractures in the formation. Currently, there are many studies...

AI Technical Summary

Problems solved by technology

Tensile fracture is the fracture that occurs when the applied stress exceeds the critical stress intensity factor of the formation when there are cracks or micro-fractures in the formation. Currently, there are many studies on tension fracture; shear fracture is an important phenomenon that occurs in the formation fracturing process. The type of fracture is mainly related to the internal friction angle, aggregation strength and formation stress of the formation. There are few studies on shear fracture, and this type of fracture is difficult to detect with microseismic monitoring methods

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