Sedimentary Facies Of EP487 Block Research And Prediction Of Tight Sandstone Gas Resources

The Canin basin is located in the northwest of Australia with a total area of more than 400 thousand square kilometers.It is a large Paleozoic inland sedimentary basin,and the trend is Northwest to Southeast.The Fitzroy trough is located in the north of Canin basin,and the Leonard shelf is the north of the Fitzroy trough.It has a sedimentary stratum of 5km thick.It is one of the key areas of oil and gas exploration in the Canin basin.The block EP487 is located at the north of the Fitzroy trough.Predecessors have done a lot of research on the area of the Fitzroy trough,but there are relatively few studies on the EP487 block.Because there is only one well in the working area,not drilling through the Laurel formation.So seismic analysis can not be carried out in conjunction with well data.This paper use the 2D seismic data and the wells data Which near the Leonard shelf in the northern Canin basin to draw the top surface tectonic map,thickness map and sedimentary facies map of the EP487 block.It is found that the late DevonianEarly Carboniferous Laurel formation in the area have many times of the paleodelta,and the multi period delta is constantly prograding to the center of the basin.Based on the comprehensive analysis of regional geological data and seismic data,it is deduced that the sediments of the delta mainly come from the eastern part of the Leonard shelf.The study is of great significance for the study of the late Devonian-Early Carboniferous climate and sedimentary environment in the area,and provides basic information for oil and gas exploration.In this paper,volumetric method and Monte Carlo model are used to calculate the resource prediction of tight sandstone gas in the block.The reservoir volume is calculated according to the thickness map of the local layers.Paper gets Net-to-gross and Porosity data form the data of wells.Combined with previous research,the degree of pore filling,water saturation,gas volume factor,condensate content in natural gas,gas composition and gas recovery rate are obtained.Finally,the prediction of the resources of the upper Laurel,middle Laurel up,middle Laurel mid,and middle Laurel low in the EP487 area is calculated,which provides a practical basis for the further exploration of the block.