Abstract:

With the rapid development of the shale gas industry in China, the shale gas geological evaluation experimental testing technology has been continuously improved. At present, a series of technology, mainly including core pretreatment, mineral composition, geochemistry, pore structure, physical properties, mechanical properties and gas content, has been formed in China. Compared with traditional sandstone, conglomerate, siltstone and other clastic reservoirs, shale reservoir, as a fine-grained deposit, has typical characteristics of low porosity and ultra-low permeability, and the natural fractures and micro nano pores develop. Therefore, it brings four challenges to the experimental technology of shale gas geological evaluation: the sedimentary microfacies are changeable, the diagenetic evolution is complex, the pore structure characterization is difficult and the fluid flow mechanism is diverse. In order to further speed up the progress of shale gas exploration and development in China and solve the bottleneck and problems in the actual production process, four directions are put forward for the experimental testing technology of shale gas geological evaluation, that is, ①the fine description of reservoir urgently needs to be developed from static characterization to dynamic evolution, ②the researches of reservoir pore and fluid occurrence mode in pore develop into simulation experiment under real geological conditions, ③the porosity characterization develops from single scale to macro-micro multi-scale integration, ④experimental data mining based on big data develops into capacity evaluation and prediction. All these are expected to provide reference for the development of the shale gas exploration and development technology and theory in China.

Key words: shale gas, geological evaluation, experimental testing technology, pore characterization, multiscale fusion