Reservoir Prediction Method Research Of SGP Structure

In east Sichuan, the Carboniferous gas reservoir of SGP structure mainly comesfrom the mud and shale in Silurian. It’s West Wing and northern end are faultshielding, and East Wing is Carboniferous formation pinch shielding. So this gasreservoir is also a structure-lithology combination traps reservoir that’s eastern,Northern and western part are trapped and southern end is opening. The reservoir-typeis fracture-pore and characterized by low-porosity, low-permeability, and strong-heterogeneity. Because most faults are reverse and buried in the research areas, andthe velocity variation is not obvious, these characters cause great difficult to thereservoir prediction including demarcation of horizons and the selection of inversionparameters.The thesis takes the Carboniferous in SGP buried structure as the target zone ofreservoir prediction. In order to further clarify the contact relation between SGPburied structure and the northern section of WQJ structure, find out the distribution ofthe fault and the carboniferous reservoir in the study area, look for oil and gasaccumulation zone, using the SGP structure3D seismic data and peripheral well block2D seismic data to do fine structural interpretation, and combining with geologic,drilling, logging data to predict reservoir by velocity inversion method. But for theSGP buried structure of low permeability reservoir characteristics of carboniferous,using a single reservoir prediction method is not able to accurately predict. So on thebasis of velocity inversion combined with porosity inversion and attribute analysis todo fine prediction of carboniferous reservoir’s effective thickness, porosity, fracturedevelopment zone for further exploration and provide basis for development of lowpermeability reserves.The results of reservoir prediction are shown: the characteristic of thecarboniferous in the study area is that at the top of the structure is thicker, the twowings is gradually thinning. In velocity inversion and porosity inversion results, thedistributions of favorable areas conform to the drilling results. On inversion sectionsthe longitudinal resolution and horizontal resolution are both high, which means thatthe inversion results is reliable and can guide the reservoir prediction. According tothe distribution of carboniferous reservoir and prediction of reservoir thickness, and combined with the analysis on the result of fracture prediction, which can providereference basis for the SGP gas field exploration and development.