Research And Application Of Prediction Methods For The Complex Reef Reservoir Based On 3D Seismic Data

With the increasing demand for oil and gas,the focus of exploration has shifted from structural reservoirs to complex reservoirs,and the carbonate reservoirs dominated by reefs occupy a very important position among many complex reservoirs.Now,there are too many reef-beach bodies have been found in the Sichuan Basin,and this area has broad prospects for exploration and development value as an important strategic succession area of "stabilizing the east and developing the west".In actual exploration and development,the conventional reef exploration methods have been relatively mature,such as the reef in Yuanba area.But people are still stuck in some exploration problems of the complex reef which is in a Sichuan work area in this paper.The reasons for these problems are as follows: 1.The reef-beach reservoir is a complex and subtle lithostratigraphic trap zone with irregular spatial distribution,which is difficult to identify in seismic section.2.The complex reef is buried deep,and it also has strong heterogeneity and multi-solutions of inversion.Therefore,no better comprehensive reservoir prediction method has been found in this place.In order to solve the problems of comprehensive prediction of complex reef reservoirs,this paper has improved the conventional phase-controlled stochastic inversion technology and summarizes a new comprehensive reservoir prediction model for the complex reef in the Sichuan Basin based on the geological understanding,seismic and log data.The main contents of this paper are as follows: 1.Analyzing and summarizing the seismic response model of the complex reef based on the instantaneous phase section,and establishing a new model which is suitable for this area.2.Using the improved phase-controlled stochastic inversion technology to predict the reservoir and study on the spatially distributing feature of this area.3.Establishing a new comprehensive reservoir prediction model for the complex reef in the Sichuan Basin combined with the ancient landform analysis techniques,the new model for seismic response of complex reef,the seismic facies analysis technology,the patent technology for fracture prediction,the analysis method of seismic attribution and the improved phasecontrolled stochastic inversion technology.The actual verification results show that the improved phase-controlled stochastic inversion technique proposed in this paper is beneficial to predict and analyze vertical and lateral distribution law for the complex reef in this area.Through comparative analysis with logging interpretation,it has been proved that the coincidence rate of reservoir prediction is higher than 85%;The new comprehensive reservoir prediction model summarized in this paper has a higher coincidence rate with the actual geological understanding and log interpretation.And it plays a good guiding role in actual production with a great practical application value.