Rock crack initiation pressure calculation method based on heat-fluid-solid coupling

Abstract

The invention discloses a rock crack initiation pressure calculation method based on heat-fluid-solid coupling. The rock crack initiation pressure calculation method comprises the steps that basic parameters of a target stratum are determined according to logging information, an indoor triaxial compression test and a Brazilian splitting test; according to the force balance equation, the constitutive equation, the transmission equation, the mass conservation equation, the heat conservation equation, the boundary conditions and the maximum tensile stress failure criterion, a rock crack initiation pressure calculation model of the Laplace space based on heat-fluid-solid coupling is established; and the rock crack initiation pressure is determined according to the basic parameters of the target stratum, the rock crack initiation pressure calculation model of the Laplace space based on heat-fluid-solid coupling and a Stehfest numerical inversion method. The coupling relation among fluid seepage, thermal diffusion and rock deformation in the shaft is fully considered; the stratum crack initiation pressure can be calculated more accurately, high-precision parameters are provided for fracturing construction design, and the requirements for reservoir evaluation and fracturing transformation guidance are met.

Description

technical field [0001] The invention relates to a calculation method for rock crack initiation pressure based on heat-fluid-solid coupling, and belongs to the technical field of oil and gas reservoir stimulation. Background technique [0002] Fracturing is an important technical measure for increasing production of oil and gas wells and increasing injection of water injection wells. From determining the construction scale, correctly selecting fracturing equipment to predicting the effect of the operation, the fracture initiation pressure is involved. Accurately predicting the fracture initiation pressure of the fracturing well is a key step in the successful implementation of hydraulic fracturing, which directly affects the effect of reservoir stimulation. Therefore, formation fracture initiation pressure is an important technical parameter in fracturing design and construction technology. [0003] At present, the traditional calculation methods of formation fracture initia...

AI Technical Summary

Problems solved by technology

Most of the calculation methods lack strict theoretical basis, take into account incomplete factors, and are quite different from the actual results. They are only applicable to specific areas, and ignore the influence of temperature changes and fluid seepage on rock fracture, not to mention the stress and pore pressure around the wellbore. changes over time

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