The Reservoir Geological Characteristics And Reservoir Prediction Of Carboniferous Huanglong Formation In North Of Southeastern Sichuan Basin

Sichuan Basin is China's major oil and gas basins. Southwestern China is also an important production base of natural gas. This exploration area is located in the southeast Sichuan Basin,with high and steep structural belt in east Sichuan and low-tectonic belt in southern Sichuan, including Fuling, Qijiang, Chishui external block, etc .The exploration area of Paleozoic gas exploration for new fields, exploration and research level low. In recent years the research and exploration work shows that the study area has good prospects for natural gas exploration, as the next step in Sichuan Basin natural gas exploration strategy to replace the area.The reservoir in southeast area of Sichuan have characteristics of low porosity and permeability, large transversal change, strong heterogeneity, invisibility, complexity and high difficulty of exploration. We finish some work such as forecast of seismic reservoir, analyzing reservoir parameter by seismic properties etc. Guiding under the research of geology, this paper analyses the reasonableness and applicability of the prognostic result and gives reasonable explain for the result. At last, we form a suit of effective way for reservoir's recognition and forecast by combining geology with exploration. Finally, it gets the following achievements:(1) Carboniferous Huanglong Formation in the study area are similar to Eastern Sichuan, mainly for a lagoon - tidal flat facies, lithology is mainly dolomite, pinhole dolomite, dolomite breccia, limestone and limestone breccia. The reservoir space is composed of corrosion pores, the development of cracks greatly affect the reservoir space.The major control factors of the reservoir development are sedimentary facies, diagenesis environment and tectonic process. (2) In this article, first is geological analysis, seismic modeling and seismic response characteristics of speech analysis, Discussed Identifiable and identify the principle of Seismic methods to predicting the fractured zone. There are four typical seismic responses in reflecting structure. Based on the theoretical models of karst units developing and sedimentary characteristics in this area, the four seismic responses in reflecting structure which we mentioned above probably means four different geologic origins.(3) Using the seismic attribute analysis technique on an estimate towards reservoir geophysics parameter, and predict reservoir thickness plane distribution of Huanglong, detection the reservoir for hydrocarbon. Application of coherent analysis technique is used to predict the fracture development in working areas.(4) Based on analysis the reservoir Geologic characteristic, reservoir prediction and the reservoir parameter prediction results, combined with the existing data, the paper makes a comprehensive evaluation for the difference kinds reservoir of the working areas, finally, points out favourable exploration areas of Carboniferous reservoir. Appear in work area for the three-dimensionalⅡ,Ⅲspecial abnormal reflection, there may be karst reservoir, which represents the role of the new type of karst reservoir that has the value of the area of potential exploration and reservoir development area.