Experimental test device and method for forced imbibition capability of shale

Abstract

The invention discloses an experimental test device and method for forced imbibition capability of shale. The test device mainly comprises a clamp holder, a press machine, a calorstat, a constant-speed constant-pressure pump, an intermediate container, a constant-speed constant-pressure pump outlet valve, a tee, an inlet valve for a fluid in the parallel bedding direction and an inlet valve for afluid in the vertical bedding direction. The test method comprises the steps of 1) rock sample processing, 2) porosity testing, 3) test parameter determining, 4) fracturing fluid preparing, 5) experimental testing and 6) imbibition capacity calculating. The test device and the test method which are disclosed by the invention have the advantages that various influencing factors such as formation stress, formation temperature, fluid injection pressure, shale anisotropy and the like can be considered in the test method to ensure that the forced imbibition capability in the different bedding directions, of the shale, can be quantitatively characterized; the change rule of the forced imbibition amount of the shale under different formation conditions with time can be accurately reflected and quantitatively tested; and very good guiding roles are played for knowing the imbibition rule of the shale and optimizing the shale volume flowback system after fracturing.

Description

technical field [0001] The invention relates to the field of petroleum and natural gas development, in particular to an experimental testing device and method for forced imbibition capacity of shale during hydraulic fracturing of shale. Background technique [0002] At present, shale gas has become a hot spot in the exploration and development of unconventional energy sources in the world. The multi-stage fracturing technology of horizontal wells is the key technology for realizing the shale gas revolution in North America. The exploration and field test of shale gas have achieved good results in increasing production. However, during the fracturing process of shale reservoirs, the fracturing fluid flowback rate is extremely low, and a large amount of fracturing fluid stays in the reservoir, but after a period of well shutdown, the production capacity increases, and the phenomenon of "low flowback, high production" appears This phenomenon has aroused widespread concern in t...

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Problems solved by technology

[0007] None of the above four methods comprehensively consider the effects of different confining pressure, formation temperature, fluid injection pressure, shale anisotropy and other factors on shale imbibition capacity. Currently, there is no method to simultaneously consider these factors and quantitatively characterize them. It is necessary to study the test method of shale imbibition capacity under real formation conditions, so as to provide a theoretical basis for understanding the mechanism of shale and fracturing fluid interaction and optimizing the flowback system

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