Study On Tight Gas Reservoir Sedimentary Microfacies And Reservoir Evaluation In The Eastern Part Of Sulige Gas Field

By the affect of depositional environment, diagenesis, structure and other factors, target layers (upper He8,lower He8,Shanl,Shan2) tight gas reservoir in the eastern part of Sulige gas field have characteristics like low prosity, low permeability, dense lithology and high heterogeneity. By means of stratigraphic classification, structual character and sedimentary microfacies study, it determined that the target layers(upper He8,Shanl,Shan2) is multi-river and low-sinuosity meandering river sedimentary system and lower He8is gentle-slope braided river sedimentary system in this area. And the main point bar, mid-channel bar, channel filling, channel flank and interdistributary bay microfacies constructed the sedimentary facies belt basic pattern. We use single sand layer energy thickness to divide the favorable sedimental facies belts. Established the maximum single sand layer energy thichness minimum standards by the sedimental energy and it’s thickness data which abstact from logging response. And delimited river-point bar and mid-channel bar framework sands’develop, scale and distributed scope. Using grey theory, integrated reservior flow, store and gas datas, established petrophysical facies flow unit "dessert" evaluation standard system. And at last, got97favorable gas zones in upper He8,lower He8,Shanl and Shan2of this area different layers. These gas-bearing favorable zones all have the very favorable gas-bearing staps and enrichment conditions.Logging interpretation and comprehensive reservoir evaluation have significantly better reservoir,seepage and gas-bearing featurers.And it becomes exploitable gas reservoirs recently or evaluation, provides a basis for area deployment rolling development wells and development preparation wells.Thus, it enhances the effect of tight gas reservoir evaluation.