High-temperature high-pressure gas reservoir permeability flow velocity sensitivity test method considering bound water

Abstract

The invention relates to a high-temperature and high-pressure gas reservoir permeability and flow velocity sensitivity test method considering bound water. The method comprises the a step of cleaning,drying and vacuumizing a rock sample and putting the rock sample into formation water for saturation for 24 hours, a step of establishing rock core bound water saturation, a step of displacing humidified gas into a rock core at a constant speed of 0.2 ml / min by a displacement pump, wherein confining pressure is greater than inlet pressure by 500psi in a displacement process, the outlet pressure is greater than return pressure in the displacement process, the humidified gas of 2PV is displaced to obtain gas logging permeability K1 of the rock core after first constant-speed displacement, a step of obtaining a gas logging permeability Ki of the rock core after ith constant-speed displacement by analogy, wherein if the change rate of the rock core permeability is greater than 20% in an nth displacement experiment, a (n-1)th displacement experiment is the moment when the rock core has velocity sensitivity, the seepage velocities of the gas at an inlet end and an outlet end of the rock core are v1 and v2 respectively, and a critical flow velocity v of the rock core is between v1 and v2. The rock permeability can be measured under the conditions of bound water, high temperature and highpressure, the critical flow velocity can be rapidly and accurately solved, and a theoretical basis is provided for the development of high-pressure gas reservoirs.

Description

Technical field [0001] The invention relates to a method for testing the influence of velocity sensitivity on rock gas permeability in the development process of oil and gas reservoirs in the field of petroleum and natural gas exploration and development. Background technique [0002] Porosity and permeability testing is the basic data for gas reservoir development. There are more mature testing methods and standards (SY / T 5336). There are also standards for core velocity sensitivity testing (SY / T 5358-2010). The current measured permeability Most of the results are obtained by simply applying the formula under certain confining pressure and normal temperature and low pressure conditions. Generally, dry cores are used for experiments. The influence of bound water on the cores is not considered, and the entry of dry experimental gas into the cores is not considered. The problem of irreducible water in the core is taken away. There is a certain error between the data obtained by th...

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Problems solved by technology

[0002] Porosity and permeability testing is the basic data for gas reservoir development. There are relatively mature testing methods and standards (SY / T 5336), and there are also standards for core flow velocity sensitivity testing (SY / T 5358-2010). Most of them are obtained by simply applying the formula under a certain confining pressure and normal temperature and low pressure conditions. Generally, dry cores are used for experiments, and the influence of bound water on the cores is not considered, let alone the dry experimental gas entering the cores. The problem of taking away the bound water in the core, there is a certain error between the data obtained by this method and the permeability of the actual reservoir rock

At the same time, for gas reservoirs, the formation pressure is high and the temperature is high, and the error between the rock permeability obtained by ordinary normal temperature and pressure experiments and the real permeability of gas reservoir rocks is even greater.

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