System and method for testing gas-water permeability saturation curve

Abstract

The invention discloses a system and a method for testing a gas-water permeability saturation curve. The system comprises a core holding unit. A first pressure return valve, a working medium bottle, acirculating pump and a heater are connected in series between a confining pressure outlet end and a confining pressure inlet end of the core holding unit; a first parallel pipeline, a second parallelpipeline and a third parallel pipeline are arranged at an inlet end of the core holding unit, the first parallel pipeline is connected to an intermediate container and a constant-speed constant-pressure pump, and the second parallel pipeline is connected to a humidifier, a pressure stabilizer, a pressure reducer and a gas cylinder; an emptying valve is arranged on the third parallel pipeline; a first parallel pipeline and a second parallel pipeline are arranged at an outlet end of the core holding unit, the first parallel pipeline is connected to a vacuum pump, and the second parallel pipeline is connected to a second pressure return valve and a metering device. The method comprises the following steps: S1, preparation; S2, saturated formation water of a core; S3, gas phase effective permeability measurement in a state of core bound water; S4, gas-water relative permeability measurement; S5, water phase effective permeability measurement in a state of residual gas of the core; and S6,gas-water permeability saturation curve drawing.

Description

technical field [0001] The invention relates to the field of oil and natural gas, in particular to a system and method for testing gas-water relative permeability curves. Background technique [0002] The gas-water relative permeability curve is an indispensable data in the water drive gas reservoir development project. It is used to calculate the water drive gas efficiency, predict the gas reservoir development index, analyze the gas reservoir It is an important basis for numerical simulation research. [0003] At present, the laboratory test of my country's gas-water relative permeability curve is mainly based on the current People's Republic of China oil and gas industry standard (SY / T5345-2007 "Measurement method for relative permeability of two-phase fluid in rock") and the national standard of the People's Republic of China (GB / T28912-2012 "Method for Determination of Relative Permeability of Two-phase Fluid in Rock"). In the aforementioned standards, the test method...

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Problems solved by technology

During the experimental test, the fluid distribution in the porous medium is a function of time and space, resulting in constant changes in the recorded data at the outlet. The reliability of the relative permeability curve test results is greatly affected by the calculation method and the accuracy of the calculation process. And there is a lack of complex data processing

At the same time, the assumptions of the theory require that the compressibility of the fluid is not considered, which is feasible for slightly compressible fluids such as oil and water, but not feasible for compressible fluids such as gas

In addition, in the actual gas reservoir development process, water drives gas, not gas drives water, and the gas-water relative permeability curve is greatly affected by the fluid saturation sequence. It has little guiding significance for the development of actual water drive gas reservoirs

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