Reservoir Characterization Of Subtle Oil/Gas Pool In Continental Sag Basin

Continental sag basin has the characters of un-developing of faults and local structure, and the traps are mainly stratigraphic traps and lithologic traps which are belong to the obscure and subtle trap. To realize the reservoir characterization of subtle oil/gas pool in continental sag basin, the Upper Paleozoic of Daniudi gas field was studied as a case by means of geological researches and geophysical prospecting and the geological researches were emphasized. The object matter includes: high resolution sequence stratigraphy & sedimentary system, predicting of microfacies & sand bodies, petrology characteristics & diagenesis of reservoirs, reservoir classifying evaluation and reservoir modeling, etc. The chief achievements and progresses are:The Chronostratigraphic sequence framework has been Constructed by using the theory of continental high resolution sequence stratigraphy. The upper paleozoic strata of Daniudi gas field is divided into 7 long sedimentary cycles and 18 middle sedimentary cycles, and the 6 long sedimentary cycles and 15 middle sedimentary cycles of Shanxi formation and lower Shihezi formation has been studied particularly. In the continental craton sag basin, due to the mild dip angle and small range of structure, the typical phenomena of faults, truncation, toplap and baselap are difficult of find in seismic section, and the sequence interfaces are generally realized the plotted from well logging data and equitime correlated by integrating of well logging and seismic data.By means of integrating geological and geophysical methods, the lithologic subtle gas pool reservoir precise characterization of Daniudi gas field was realized. Using multi-methods of seismic analysis such as normal incidence, inversion and attribute analyzing, and integrating well drilling, well log analyzing, etc. the result shows that the shape of sand bodies are banding, wedgelike, lentoid, local furcated...