Framework Of Paleogene Sequence Stratigraphy And Prediction Of Litho-traps Distribution, Hainan-Xianhe Area, Liaohe Basin

Aiming at the questions that the structural traps have been difficult to find andthe research on the litho-traps was asked to be furthered in Hainan-Xianhe area,According to the theory of petroleum geology, high resolution sequence stratigraphyand the technology of geophysics, combined with the core data, the seismic data, thelogging data and the test data, the sequence stratigraphy and the litho-trap have beenstudied in this paper. Six third-order sequences has been recognized in the paleogeneformation of Shahejie and Dongying. The framework of paleogene sequencestratigraphy has been established in this paper. The structure has been re-interpretedwith 3D data. It was the S-N transfer fault that provided the channel for thepaleo-current entered into the faulting lake during Shahejie three period. The structurehigh and the structure low were controlled by the strike-slip fault, the structure lowwas developed in the releasing bend of the strike-slip fault, the distribution ofchannels was controlled by the structure low and therefore the channels entered thelake were along the releasing bend. This rules are very important for the favorablereservoirs prediction.Strata division and srata correlation are the basics of geological study. Throughthe high resolution sequence statigraphy study, the geomorphology was higher in thesouthern area than that in the northern area during the period of Shahejie three andDongying formation . The sedimentation volume partition and the facies differentiationwere controlled by geomorphology. Based on the theory of sequence stratigraphy, fandelta sedimentary system of Shahejie and Dongying formation which was fromHainan-Yuedong buried hill has been recognized through core data, logging data andseismic data analysis. The paleo-currents and the sub-channel branches developed alongthe paleo-geomorphology low of the faulting slope break, and the mouth bar wasdeveloped below the faulting slope break. However, the paleo-geomorpholgy high wasoccupied by the sandy mud and the mud. Therefore, the favorable reservoirs aresub-channel branches sand bodies and mouth bar sand bodies.The sub-channel branch sand bodies have been successfully predicted throughthe techniques of seismic attributes analysis, seismic coherence process, seismicfacies analysis, 3D visualization and 3D seismic inversion in the framework ofsequence stratigraphy. The promising exploration target and the distribution oflitho-traps have been pointed out and clear.