Analysis Of High Resolution Sequence Stratigraphy And Reservoir Characteristics Of Chang6Oil-bearing Formation, Upper Triassic In Gutun Exploration Area, Ganguyi Oilfield

Ganguyi oil exploration area is located in Baota district of Yanan city. The regional structure of the studied area belongs to Shanbei slope of Ordos basin. Based on the theories of sedimentology, reservoir geology, logging geology, high-resolution sequence stratigraphy and petroleum geology, the author has researched the sedimentary facies, high-resolutio sequence stratigraphy and sandbody distribution in sequence stratigraphic framework of Chang-6Oil-bearing Formation, Yanchang Formation, Upper Triassic in Gutun exploration area, Ganguyi oilfield. The main achievements and understandings are as follow:The Chang-6oil-bearing formation can be divided into1long term base-level cycle,4mid-term base-level cycles,10short term base-level cycles and several super-short term base-level cycles. The model of stratigraphic division, made by other experts, studies the high-resolution sequence characters and structure of chang-6systematically, and sets up the high-resolution sequence stratigraphic theory, with the mid-term base-level cycle formation as the isochronal contrast unit. On that basis, the high-resolution sequence stratigraphic contrast profile of Chang-6oil layer is worked out.Based on the study of the sedimentary facies and sedimentary microfacies within the sequence framework, it is considered that the Chang-6reservior sedimentary facies belongs to the lake delta deposit, mainly developing front-delta and delta plain subfacies deposition. By analysing the combination of core and logging presentation character, we set up the logging facies model, recognizing the distributary channel, the distributary bay, the submerged distributary channel, the submerged distributary bay and the mouth bar.The paper mainly researched on the petrologic characteristics, the types of the diagenesis, pore structure, the physical property characteristics and the homogeneity of Chang-6reservoir. Based on the sedimentary micorfacies and reservoir researches, this study sums up the the spread rule of advanced area from the vertical and the plan view out of the sequence framework.