Research Of Shahejie Formation's Hydrocarbon Accumulation Rules Of Daliuquan-Hexiwu In Langgu Depression

In order to research the hydrocarbon accumulation regularity and predict the favorable zones of the mid-sha3 member in the Daliuquan structure belt,the contribution of the hydrocarbon accumulation elements such as the source,reservoir and conducting condition trap el.is researched on the basis of their development and distribution characteristics.It is recovered that migration and preservation conditions are two vital factors for hydrocarbon accumulation degree of the study area.The migration condition of hydrocarbon is controlled by the advantage migration pathway and the sand ratio reservoir which can be a quantitatively represent by the hydrocarbon migration index.While the preservation conditions of hydrocarbon is controlled by the vertical sealing ability of caprock and the lateral sealing ability of fault which can be a quantitatively represent by the hydrocarbon preservation index.According to drilling data in this area,a new evaluation method migration and preservation condition is put forward,namely hydrocarbon migration index and hydrocarbon preservation index.In accordance with the comparison and analysis of quantitative relation between the hydrocarbon migration index,preservation index and each influencing factors of hydrocarbon accumulation for the drilled wells,the evaluation formula for predicting hydrocarbon enrichment degree in the undrilled area has been established.The predicted result using this method for hydrocarbon enrichment of each trap in the mid-sha3 member of Daliuquan area has a high coincidence rate with the current drilling results...