The Research Of The Accumulation Rule Of Shallow Gas In Xingshugang Structure Heidimiao Oil Layer

Songliao Basin's late reversal deformation is the active factor in the formation of Daqing Changyuan,thus forming a large anticline,Xingshugang structure is located in central Daqing Changyuan,northern is Saertu structure,southern is Taipingtun structure.The plane is the long north-south anticline to the vertical structure,section to section shows characteristics of steep anticline is the west wing,and gentle anticline is the east wing.The main activities of faults in Xingshugang mainly have three strong activities: the Qingshankou group,Yaojia group one or two section and three or four since one or two.On the basis of fault formation period,deformation characteristics and fault crossing layer,Xingshugang area can be divided into 6 sets of fault systems: the early Qingshankou formation fault system,the middle Nen one or two section of fault system,advanced Nen three or four fault systems,the early Qingshankou Formation in mid-Nen one or two fault system,the middle Nen one or two section since the late Nen three or four fault system,early Qingshankou formation since middle-late Nen one or two paragraph three or four since the fault system.The objective layer of study area is Heidimiao oil layer,composed of Nen two,Nen three,Nen four strata,Heidimiao oil layer in the North East to the provenance,sedimentary water from bottom to top gradually becomes shallow,the types of sedimentary micro faces mainly include underwater distributary channel,estuary bar,inter-distributary bay,far sand bar,sheet sand,shallow lake,underwater distributary channel,estuary bar.The shallow gas in Daqing Changyuan Xingshugang structure Heidimiao shallow burial,is easy to develop,high economic efficiency,is the reality field of increasing reserves and production recently,in order to clear the rule of shallow gas accumulation,and get the prediction of favorable zone,through the analysis of Daqing Changyuan Xingshugang structure Heidimiao oil layer's natural gas formation factor,gas source,reservoir,trap,comprehensive analysis of fracture,the cover layer,the shallow gas accumulation,and at the same time according to the forward model,the analysis of AVO curve in the region,the results showed when there is water in the reservoir,the performance is a kind of abnormal AVO,increase with offset,amplitude value decreases;When there is gas in the reservoir,the performance includes three kinds of abnormal AVO,increase with offset,amplitude absolute value becomes larger,so most of the predicted gas concentration in H34 layer,as the main reservoir,gas and water's interface in near 600 m deep,which provide direction of prospection and exploration of Daqing Changyuan Heidimiao shallow gas.