Gas reservoir water lock damage experiment evaluation method

Abstract

The invention discloses a gas reservoir water lock damage experiment evaluation method, which can accurately grasp the water lock damage rule of a gas reservoir and provide a basis for gas reservoir related engineering operation decision. The method comprises the following steps: S1, experiment preparation: obtaining an actual reservoir rock core of a gas reservoir, cleaning, drying, testing parameters of the rock core, and preparing a water locking experiment device; and performing rock core saturation experiment formation water; S2, setting a plurality of water saturations of the rock core, and calculating the critical capillary pressure of the rock core under the corresponding water saturation; S3, measuring the permeability of the rock core; and S4, evaluating the water locking damage.

Description

technical field [0001] The invention relates to the technical field of gas reservoir exploitation, in particular to an experimental evaluation method for water lock damage of gas reservoir reservoirs. Background technique [0002] After the water-based working fluid enters the gas reservoir, the water saturation of the reservoir rises, leading to an increase in gas phase flow resistance and a decrease in gas phase permeability. This phenomenon is called "water lock effect" or "water lock damage". Water lock damage in the reservoir will lead to reduced gas well productivity, increased operating costs, reduced natural gas recovery, and poor economic benefits for gas reservoir development. Usually, water lock damage usually occurs in low-permeability gas reservoirs. The foreign water-based working fluid invades the pores of the reservoir, causing water phase traps in the reservoir around the wellbore of the gas well, restricting the flow of the original reservoir fluid to the w...

AI Technical Summary

Problems solved by technology

Although the above two methods are relatively mature in evaluating the degree of water lock damage in reservoirs, the existing methods cannot obtain reasonable gas displacement pressure differences at different water saturations, which may cause gas flooding during core experiments. The problem of the same flow of gas and water, so the experimental results cannot accurately reflect the influence of different water saturations on gas seepage during the natural gas production process

At the same time, because the existing methods cannot accurately obtain the water phase saturation under a certain degree of water lock damage, the evaluation results of water lock damage may seriously deviate from the real situation, and the guiding effect on mine application is limited

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