Numerical Simulation Of. Qibei Depression Diagenesis And Porosity Prediction

Nonce, the system of diagenetic numerical modeling for the stratum under the conditions of normal pressure has been set up .In lots of sags rich of petroleum in the basins of eastern China, such as Qibei sag of Bohaiwan basin, There are plenty of deep-buried overpressure reservoir. However ,the diagenetic numerical modeling is not perfect ,to say nothing of porosity prediction.Overpressures raise the activity energy of diagenetic reactions. In this thesis, the chemical kinetic models with higher active energy enhanced by overpressure factors could be used for modeling the organic matter maturation and diagenetic history of the overpressured formation. As the diagenetic modeling results of the Qibei sag show, at the end of the Shahejie Formation (Es) deposition the Shasan Member (Es3) entered the late diagenetic stage A1; the oil and gas pools formed from since. From the Dongying Formation(Ed) to Neogene, the Shahejie Formation was located in the late diagenetic stage A1~A2; The oil and gas pools formed in a wide scale. At present the lower E2S3, with overmatured source rocks and low porosity reservoir rocks, gets into the late diagenetic stage B-C in the northern Qibei Sag where is not favorable for petroleum accumulation, but the others of the Shahejie Formation are locate still in the late diagenetic stage A1-A2 and propitious to form oil and gas poolsBased on the diagenetic numerical modeling under the condition of overpressure, We build a multiple unit cubic equation model for porosity prediction ,as the result of the application of Qibei sag ,the prediction error is less than 2%,and the precision excess that of foreign same model.