High Resolution Sequence Stratigraphy And Favorable Reservoir Distribution Of Member 3 Shahejie Formation In KL10-1 Oil Field

KL10-1 Oilfield,located in the north depression of the Laizhou Bay,is still in the early development phase.The structure is complicated with developed faults.The highresolution sequence stratigraphy,sedimentary facies and spatial distribution patterns of high-quality reservoirs have been studied by comprehensive use of geological,logging,and seismic data,which provide geological basis for oilfield development plan.By analyzing and combing seismic and logging responses,sequence boundaries at different levels are recognized.Hence,seismic section identification of sequence boundaries,single-well analysis and multi-well uniformizing are conducted.At the same time,on the basis of sedimentary evolution,the high resolution stratigraphic framework of E2S3 is established,that is,4 system tracts,16 parasequence sets and 47 parasequeces.Within the high-resolution isochronous stratigraphic framework and through integrated application of core,logging and seismic attribute slice analysis technology,the research on sedimentary facies,sedimentary microfacies and reservoir space distribution of E2S3 is carried out.According to the predecessors' research results and the electrofacies analyzes,E2S3 of KL10-1 Oilfield is classified into braided-river delta front subfacies.And braided-river delta front subfacies can be further divided into microfacies including distributary channel,estuary bar,sheet sand and interchannel.The estuary bar sands are mostly developed,followed by distributary channel sands of E2S3 M.And the distributary channel sands are mostly developed in E2S3 U.According to statistics,the thicknesses of single sand bodies are between 1.5~5m,the porosities are between 5%~30% and the permeabilities are between 10~500mD.The reservoirs are of moderate porosity and moderate permeability.Studies show that reservoirs of progradational parasequence sets in the lowstand system tract and highstand system tract are well-developed.The favorable reservoirs are located at the center of the distributary channel and estuary bar sands,and they are strip-shaped and potato-shaped.By adopting reasonable strata slicing scheme,on the basis of single-well comprehensive evaluation and through seismic attribute extraction and optimization,this paper achieves the prediction of favorable reservoir facies blets and the horizontal distribution of high-quality reservoirs,which provides solid geologic foundation for oil field development plan.