Research On High-resolution Sequence Stratigraphy And Reservoir Prediction

As the conventional hydrocarbon reservoirs could not meet the needs of economy development, it is necessary to reserch on unconventional hydrocarbon reservoirs. It shows a developing trend from the shallow to deep reservoirs. Large buried depth , complex surface and subsurface geologic conditions resulting in low signal/noise ratio, which restricts the better understand subsurface geologic conditions. How to apply new technique for enhancing of exploration and discovering new petroleum provinces is a question urgently sloved in oil-gas exploration of the area.Base on the sedimentology, mud log and conventional log, the sedimentary facies of marine delta, shore and continental shelf of zhuhai formation, and fan delta, braided river, lacustrine and lake delta of Enping formation have been recognized. And depositional models of fluvial-dominated delta- shore and braided river-lacustrine- lake delta have been stablished. On base of integrating well data and seismic data, combined with the high resolution sequence stratigraphic theory, Zhuhai formation and Enping formation were divided into short-term ,middle-term and long-term base-level cycle. The structure of the short-term base-level cycle could be subdivided into asymmetric up-deepening , asymmetric up-shallowening and symmetric basic structure types. The base-level cycles of different orders are correlated in the restriction of seismic interpretations and method of cycle isochrostratigraphy correlation. Isochronous stratigraphic frameworks are established and single sand-body is correlated within them. The distribution and evolution of reservoir and the controls factor of reservoir quality are analyzed within isochronous stratigraphic frameworks. Base on LF model restricting by the isochronous stratigraphic frameworks of middle-term and long-term base-level cycl, the inversion of GR pseudo- acoustic have been made. Using the soft of 3D Interwell, calibrating the objective layers of sandbodies, the distribution shape of sandbodies have been traced and described with horizon calibration. Application of High resolution Sequence-based lithofacies and paleogeography, seismic facies analysis,and seismic attributes analysis, A synthetic prediction method for reservoirs was proposed. The metoth for reservoir predicted can improve the precision of forecasting and effectively recognize subtle oil and gas reservoir.Finally, according to sedimentary facies, the sand bodies area, bodies thickness, porosity and permeability, and the oil-bearing area, the favorable area of deep reservoirs have been estimated, which supply the reliable sedimentary and sequence stratigraphic evidence to proceed exploration and development of oil and gas.