Experimental test method for gas reservoir reverse imbibition water blocking damage evaluation under high-temperature and high-pressure condition

Abstract

The invention discloses an experimental test method for gas reservoir reverse imbibition water blocking damage evaluation under a high-temperature and high-pressure condition. The experimental test method is completed through a water blocking effect experimental measuring device. The experimental test method comprises the steps that firstly, a core is washed and dried to be placed into a core holding unit; secondly, the core is vacuumized, displacement pressure is increased to formation pressure Pf, and formation water is injected into the core under constant pressure; thirdly, the temperature is raised to the formation temperature T0; fourthly, nitrogen is injected into the core, displacement is carried out until the liquid level of a water measuring meter at the core outlet end does not change, and gas phase permeability K1 is calculated; fifthly, formation water is injected into the core until no gas is discharged out of the core outlet end; sixthly, secondary gas driving water is carried out on the core, displacement is carried out until the liquid level of the water measuring meter at the core outlet end does not change, and gas phase permeability K2 is calculated; seventhly, the damage degree of water blocking damage to the gas phase permeability is determined. The experimental test method conforms to the actual gas reservoir developing process, a reasonable testing method is provided for reservoir water blocking damage measuring evaluation, and the experimental test method has wide market prospects.

Description

technical field [0001] The invention relates to an experimental measurement method for evaluating the reverse osmosis water absorption and water locking effect of reservoirs in the near-well zone during the development of oil and gas reservoirs in the technical field of petroleum and natural gas exploration and development. Background technique [0002] The water lock effect is a common damage method in the seepage of low-permeability gas reservoirs, which is caused by the external water entering the core to occupy the gas circulation channel and blocking the continuity of the gas. During the development of gas reservoirs, foreign liquid phases such as drilling fluid, cementing fluid, perforating fluid, and acidizing fracturing fluid invade the reservoir near the wellbore under the action of pressure difference and capillary force, resulting in water saturation and capillary pressure in this area. The pressure increases, thereby increasing the gas phase seepage resistance an...

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Problems solved by technology

The evaluation of water lock effect and the release of differential pressure generally adopt laboratory test methods, but the existing experimental test methods do not consider the actual development process of gas reservoirs

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