Method for simultaneously testing porosity and permeability of porous rock under conditions of triaxial stress and pore pressure

Abstract

The invention, which belongs to the field of rock reservoir engineering research, discloses a method for simultaneously testing the porosity and permeability of the porous rock under conditions of triaxial stress and pore pressure. According to the method, upstream and downstream motor servo pumps apply pore pressures to a reservoir rock sample in a triaxial stress state; fluid pressures in the pumps are set and fluid volume data in the pumps are obtained to realize testing the rock pore volume under the pore pressure condition. An injection pump and a collection pump are used for adjusting anosmotic pressure difference and the flow through the rock under the pressure difference is tested, so that the permeability under the stress state is obtained. According to the invention, with setting of different confining pressure conditions, biasing conditions and fluid pressure values at the upper and lower ends of the rock sample, the porosity and permeability values of the reservoir rockunder different stress and pore pressure conditions are tested simultaneously to provide technical parameters for controlling the exploration and injection process of the fluid substances in the deepporous rock reservoir.

Description

technical field [0001] The invention relates to a method for simultaneously testing the porosity and permeability of porous rocks under the conditions of triaxial stress and pore pressure. The testing method is mainly aimed at porous rocks in reservoirs and belongs to the research category of rock reservoir engineering. It is mainly used to study the co-evolution law of storage space and permeability of porous rock reservoirs under different water pressure and formation stress environments. It is suitable for experimental research on multi-field coupling scientific issues in the process of extraction and injection of fluid materials in deep porous rock reservoirs. Background technique [0002] Permeability coefficient and porosity are important evaluation indexes in porous rock reservoir engineering. Carbon dioxide geological storage, coal bed methane and geothermal exploitation, geological disposal of nuclear waste, and seawater recharge are all storage projects. During t...

AI Technical Summary

Problems solved by technology

[0003] At present, for the test method for simultaneous determination of rock porosity and permeability under stress conditions, for example, Chinese Patent Publication No.: CN 103207138 A Publication Date: 2013.07.17 The title of the invention is "A joint measurement of tight rock permeability and permeability under dynamic confining pressure. For tight rocks, this method adopts the transient method of gas pressure difference, which is not suitable for rocks with large porosity and high permeability, and the influence of bias pressure on rocks is not considered in the test process. The influence of permeability and porosity, and the influence of pipeline passage and rock sample casing sidewall voids on test results were not analyzed

At present, most of the equipment for measuring permeability and porosity using the steady-state method are independent of each other and do not take into account complex in-situ stress conditions and pore pressure changes.

Images