Research On Forming Conditions And Regionalization Of Tight Gas In Turpan-hami Basin

Turpan-hami Basin,which is rich in coal,is located in the eastern xinjiang in china.It has the basis of forming large-scale natural gas accumulation.However,due to tight reservoirs,it can only form tight gas reservoirs.On the basis of an extensive collection and analysis of results of previous studies,thesis integrated use of laboratory analysis testing and logging data,etc.study the tight gas and oil accumulation conditions,the enrichment regularity in Jurassic of Turpan-hami Basin and pointed out the favorable target tight oil drilling.Taking the Taibei depression as an example to study the forming conditions of tight gas: 1.Its main hydrocarbon source rocks is coal bed from the middle and lower Jurassic Shuixigou group.And the organic matter,mainly type ?,has entered the mature threshold mostly;2.The reservoir developed in a wide range of continuous sheet sand body,the lithology is mainly feldsparthic lithic sandstone,the compositional maturity and the textural maturity are low in this area,reservoir space is mainly intragranular dissolution pores,intergranular pores and microcracks.The late diagenetic evolution is a key factor of reservoir densification;3.The source-reservoir combination is good,the reservoirs were densificated in the late Jurassic,then accumulated in the cretaceous period,forming “pre-exiting tight gas reservoir”.The favorable zones are predicted by compositing the tight gas hydrocarbon source rocks conditions and reservoir conditions,taking CNPC tight sandstone gas selection criteria as a reference at the same time.Five favorable zones are slected,including: northeast of qiudong sag,north of Shengbei sub-sag,west of Xiaocaohu sub-sag,southwest of Tuokexun depression,and the east of Sanbu sag.Using the small bin volumetric method to computing resouces,it is concluded that basin in the tight sandstone gas resource of 3446.9×108m3.After set up a comprehensive evaluation index system,The five favorable zones for the comprehensive evaluation is divided into five divisions object using the double factor method: priority exploration(development)area,secondary exploration(development)area and exploration reserve(development)area.For the next step of dense gas exploration and development,the completion of thesis has important guidance and reference significance.