High-resolution Sequence Stratigraphy Study And Selection Of Profitable Area In East Of Zhaozhou Area

Taking high-resolution sequence stratigraphy and sedimentology theories as guidance, this study accurately used well core, well logging and the 3-D seismic data, etc in this area.Through depositional dynamic analysis of different grades base level cycle and identification of interface, method of high-resolution sequence stratigraphic fine division and correlation is presented which is fit to meandering river delta. It is a method that correlation of base level cycles interfaces are come near under the control of gradual marker chronohorizon. By the method, Putaohua oil layer of Zhaozhou area is divided into one long-term, two medium, Twelve short -term base level cycles for the first time, established high-resolution sequence stratigraphic framework, and proposed sequence stratigraphic model, "thinning the thickness of the basin, gradually thin layers, the middle is the largest surface of the water back down to base level lowering& the base level up" development pattern formation.Within the fine sequence stratigraphic framework, sources of sediments, and distribution of sedimentary facies are analyzed. The shallow lacustrine fluvial-dominated delta system of Putaohua oil layer is presented which is controlled by the NW-SW river system of north depositional system of Songliao basin.It is realized that distributary channel sandbodies are sand body framework , they are also NW-SW, distributary channel sandbodies is mainly reservoir sandbodies of Putaohua oil layer.Based on sequence stratigraphic framework and distribution of its sandbody, through systematically analyzing types of found reservoirs and its distribution characteristics,. the distribution of reservoirs is mainly controlled by three geological factors:â—‹1 Single sand body is whether communicate with the source fault,only sand that communicated,oil and gas can migration into its and accumulation.â—‹2 Physical properties of single bodies,sand of good properties are easier to accumulate hydrocarbon in the same context.â—‹3 Fault on both sides of the alignment of sand, fault on both sides of single bodies docking is good,is not conducive to oil and gas block,the oil is poor.Based on all the conclusions above, it is predicted that favorable hydrocarbon accumulation zones are Shangnan nose structure, the north wings of Shangjia and the slope of Fengle, 8 favorable traps are predicted, and 10 wells are deployed.