Study On Trap Evaluation Of Feixianguan Formation Of Triassic In Northeastern Sichuan

In recent years,with the deepening of exploration activity in the Feixianguan Formation in the northeast of Sichuan Basin and the improving of the three-dimensionnal seismic exploration area and data resolution.The prediction of the distribution of oolitic shoal in Feixianguan Formation has also made new progress.Therefore,it is necessary to re-sort and evaluate the traps of Feixianguan Formation in study area.This study is of great significance for the exploration and deployment in the future.The analysis of the paper is based on the theory of sedimentary petrology,tectonic geology,hydrocarbon accumulation theory and so on,combing full using of drilling,logging,well logging,seismic interpretation and gas reservoir development data.On the basis of latest seismic structural interpretation and reservoir prediction results,this paper identify and describe the traps of Feixianguan Formation in the Northeast Sichuan Basin,moreover 78 traps undrilled is identified.Finally 56 unexplored traps which area larger than 5 square kilometers are choosen as the main object of evaluation.Based on the quantitative evaluation of hydrocarbon accumulation conditions,this paper using the probability of trap formation by means of Delphi method.Combing the characteristics of gas pool fund and the results of previous studies.This paper finally select 17 parameters for each traps evaluation from five aspects of hydrocarbon source,reservoir,trap,preservation conditions and reservoir matching history.Respectively,through the establishment of quantitative evaluation scale and risk probability method,reservoir forming conditions of each trap is quantitatively evaluated.With the proven gas reservoir traps,the geologic analogy method is used to calculate the parameters of the unexplored traps.The area abundance method and volumetric method(reservoir-trap-volume-method)were used to calculate the amount of resources,and it is concluded that the volumetric method is more in line with the actual exploration results.On the basis of research results above,with the results of trap collection probability analysis and resource calculation,the paper combined the two factors comprehensive evaluation method and multi-factor classification method to classificate and queue for 56 unexplored traps in Feixianguan Formation,and choose four traps as targets for recent priority exploration.