Research Of Gas Shale Reservoir's Fracability In South Sichuan Basin

Shale gas is an important unconventional energy,shale gas reserve in South Sichuan is abundant,and the area's research and development is needed to be focus on.In this paper,shale samples of South Sichuan shale gas reservoirs are conducted experiments and analysis.With the experiments of shale samples from different layers in South Sichuan shale gas reservoirs,the key factors of shale fracability in South Sichuan Basin are deeply investigated.And the experiments of shale samples include Mineral composition analysis,shale microscopic electron microscopy experiments and mechanical parameters experiments in conditions of different temperature.Additionally,the effect of temperature stress caused by thermal effects in shale gas reservoir to shale fracability,is considered in this paper.And it is also analyzed that whether the temperature effect can serve as one of the important factors.With a series of laboratory test and simulation analysis results,Shale samples from different blocks and layers of shale gas reservoir,have a big difference in rock physical properties and mechanical properties,but the fracability of the shale gas reservoir in South Sichuan Basin is in a good condition.With the experiments of rock physical properties under different temperatures,the thermal effect has an impact on the physical properties and mechanical properties of shale samples.When the temperature decreases,the increments of shale compressive strength and elastic modulus is small,Poisson's ratio did not change significantly;With the increase of confining pressure,shale samples under different temperature conditions showed a transition phenomenon from brittle failure to ductile failure;In addition,the tensile strength of shale formation can be reduced by the thermal stress caused by temperature difference,and it is good for the fracturing of gas shale reservoir in South Sichuan Basin.