Shale Gas Accumulation Conditions And Favorable Area Prediction Of Lower Paleozoic In Southern Henan

This thesis mainly focuses on the shale gas accumulation condition evaluation of the lower Cambrian Xinji,Madian and the corresponding shale formations in the south of Henan province.Through field investigating,lithologic features observing and the outcrops collecting,integrating tectonic paleogeography and sedimentary environment of the research area,combining with geochemical experimental methods,by means of maturity,type and abundance of organic matter and adsorption tests.Take shale gas accumulation standards to measure the stratigraphic property,source rock,accumulation condition of this formation.It's found that the accumulation condition is well.The sedimentary environment of the Xinji formation in the research area is mainly shallow sea shelf,existing trough sedimentation in the Gushi area of Huoqiu,the thickness of the shale in the research area has a downward trend from south to north.The kerogen type of the research area is mainly type I and II,the maturity is high and showing a circular distribution which decreasing from the center to the outside.There almost no conventional pores are development in the research area,the micro pores and micro cracks constitute the main storage space,and the mesoporous is the mainly nanopores types.The buried depth is different in the different area,in the south of Henan District in Gushi Huoqiu area,the dark shale thickness of the lower Cambrian Xinji formation is 10-100 m,the buried depth is between 2000 m and 3800 m and the maturity is high(higher than 1.0%),the organic matter content is high(higher than 4.0%)and the average value of the brittleness index is 0.59%.According to the preferred exploration area standard of the shale gas,the Gushi Huoqiu area is a favorable area for shale gas accumulation.