Sequence Stratigraphy Model And Geo-seismic Reservoir Prediction Method In Tertiary Of Bohai Offshore

The high investment, high risk, and few wells condition of Bohai offshore exploration meet great challenge because of ambiguity of seismic data, and the key problem is reservoir prediction. Geo-seismic reservoir prediction method is developed according to the situation. Its main idea is to establish geology and seismic integrated reservoir prediction method which is guided by geologic sand control model together with evolution of structure and sequence stratigraphy, and to establish special seismic method corresponding with different geologic background in few wells exploration area. The method can utmost decrease the ambiguity of seismic data and increase the accuracy of reservoir prediction, and to give great teleology support to expolration of Bohai offshore area.From seismic stratigraphy to sequence stratigraphy and to seismic sedimentology, seismic exploration teleology always integrates with geology. But the integration is relatively in low steps because of the completely applying and higher resolution studying of sequence stratigraphy, as well as swift and violent development of 3D seismics, which lead to some problems and misunderstanding. To clear the misunderstanding, even deeper integration must be done among regional geology, sequence stratigraphy, and seismic study.Based on the distinguished geology characteristics and their relationships to the depositional sand bodies, time-space-source dynamic control model for sand body characteristics is suggested. The main idea is that characteristics of sand body are controlled by dynamic changes of sequence, palaeogeomorphology and source, and the essence is their co-working together. Respectively,dynamic source control the scale of sand body, and sequence evolution control the inside configuration of the sand body, and change of palaeogeomorphology control the overriding of several sand bodies.Geo-seismic reservoir prediction method of few wells condition is to figure out the possible characteristics of sand bodies and their around rock background by time-space-source dynamic control model, and to integrate seismic method to indicate seismic response of the sand bodies, then to predict them. At first the characteristics of sand bodies and their relationships to claystone is defined according to sequence study. Then impedance of assemblage of micro-face is defined according to sedimentary study. And finally, proper seismic method is chosen to predict, describe, and interpret the sand bodies. There are 3 contents in Geo-seismic reservoir prediction method, prediction method four well-developed sand area, description of pinching out line, and interpretation of sand body.Geo-seismic reservoir prediction method gives effective way to predict reservoir under few well condition characterized by choosing proper seismic methods under control of geology study. Application of the method in JZ25-1 and BZ34 achieves good results, and contribute a lot for the discovery and evaluation of the oil fields.