Evaluation On Resource Potential Of Shale Gas In Huainan Stratigraphic Microprovince

In consideration of Geochemical Characteristics,sedimentary characteristics,mineral composition, The space distribution characteristics of reservoir,gas contentand so on in Shanxi Formation and Lower Shihezi Formation shale of huainan region, making reference to the experience of Favorable exploration zones of shale gas for north American,and combied with reservoir factors, economic benefits,and resource scale, on the basis of the three aspects. and then choosing the seven factors of shale gas as an important indicator of favorable area preferred necessary and appropriate to establish a favorable shale gas areas preferred model. The weights of favorable areas evaluation is identified by the AHP. statistical analogy, undetermined coefficient method and fuzzy statistical are used to determine the membership valuesof each evaluation parameter.Finally, based on the evaluation method of fuzzy optimization technology, combined with GIS spatial overlay technology, make a comprehensive evaluation and prediction of favorable area for Shanxi Formation and Lower Shihezi Formation shale gas in Huainan area.Through the research analysis show that the depositional environment of Carboniferous-permian in the study area was Marine-terrigenous deposit-continental sedimentation, it formed a good hydrocarbon source rock of containing. The thickness of the Shanxi shale is in the range of30-60m, averagely39m. The thickness of the Shanxi coal is in the range of2-8m, averagely5.6m.they contain high amount of organic matter. they contain high amount of organic matte.the hale has total organic Carbon(TOC)generally1-2%and the highest value of8.4%. the coal has total organic Carbon(TOC) averagely65.16%; The thickness of the Lower Shihezi shale is in the range of30-95m and the highest value of110m, averagely75m. The thickness of the Shanxi coal is in the range of6-16m, averagely10.4m.the total organic Carbon(TOC) of the coal and the hale in the Lower Shihezi Formation is all lower than the Shanxi Formation’s. the hale has total organic Carbon(TOC)generally0.8～4.32%.the coal has total organic Carbon(TOC) averagely56.98%.The main two target stratums in the study area organic type Ⅱ2, Mixing with a small amount of kerogen type Ⅱ1andⅢ. The main two target stratums organic matter are basically at maturity and Parts to medium-high maturity which were judged by the Rock pyrolysis peak temperature and Romax.The pores mainly are In the organic matter, minerals, between the organic matter and the minerals and the microcrack.Resources in place of shale gas in two shale systems are calculated using volumetric method in the different depths of the study area. The Results show that the toal reserves are14.41～17.67×1011m3, the toal reserves in the Shanxi Formation are9.91～12.3×1011m3, the shale gas reserves are7.21～8.91×1011m3; The coal gas reserves are2.71～3.39×1011m3; the toal reserves in the Lower Shihezi Formation are4.5～5.37×1011m3, the shale gas reserves are3.26-3.69×1011m3; The coal gas reserves are1.24-1.68×1011m3.The main two target stratums have good resource potential Compared with the Antrim shale in North American and Huai ren shale in east Sichuan form the resource abundant.In the present study,with the help of the Fuzzy Synthetic Evaluation, the favorite shale gas plays in thisstudy area have been identified.The most prospective areas are situated at Gudian town-Guqiao-Guiji-Liauji、Yanglou town and the southeast region in the study area for the Shanxi Formation;and the highestpotential areas are Hetuan town-Dingi、Xinji town、Pingwei town and Gaohuang town for the Lower Shihezi Formation.