Fault-Block Mountain Oil Reservoirs and Reservoir Heterogeneity of Tongbomiao Formation in Tanan SAG

摘要

The oil productivity of each developed block in Tanan Oilfield varies to a great deal and moreover is seriously influenced by the reservoir heterogeneity. Taking the palaeo-fault-block mountain oil reservoirs in Tongbomiao Formation of Tanan Sag as the cut-in point, with the help of the well-seismic assemblage, core observation and cast thin section analysis, on the basis of the division of the reservoir type, the reservoir reforming model and heterogeneity were researched, thus the adjustments of the developing program were guided. The achievements show that according to the fault scale and formation dip, the oil reservoirs can be classified into two types: deep-fault high-dip type and shallow-fault low-dip type; for different kinds of the fault-block oil reservoir, two types of the reservoir reforming models can be classified: high-angle two-lateral reforming type and slope leaching type; the inner-layer heterogeneity of the reservoir is controlled by the original sedimentary conditions, inter-layer heterogeneity of the reservoir is dominated by the unconformity, the planar heterogeneity of the reservoir is controlled by the structural location and fractures. The development of the former type of the reservoir takes the progressive out-stepping of the fault slope as the adjusting method, while the development of the latter regards the partial infilling in the structural high area as the adjusting measure.