High-resolution Sequence Stratigraphy And Characteristics Of Reservoir Of The Forth Member Of Paleogene Shahejie Formation In Qingdong Sag

Regarded sedimentology，seismic stratigraphy, reservoir sedimentology and other disciplinesas the theoretical guidelines, the forth member of Oligocene Shahejie Formation in Qingdong Sagwas studied as the main target for identifying favorable sand type, evaluating of reservoir qualityand guiding subtle reservoir exploration as the fundamental purpose. The type of sedimentaryfacies and distrbution of the sedimentary system, and analysised the reservoir characteristics wasdeeply discussed. The material of core, petrographic slice,3D seismic,well log and etc. were mailyapplied in this study. Combining the analysis of control factor of reservior quality andachievement of the former study, the favorable zone of oil in Qingdong area was forcasted.The32well-core material was observed and analysised in detail. On the basis of petrologicalfeature, boratory data, seismic reflection form, and electrofacies, the sedimentary facies andsystem was analysised. The study showed that fan dalta, dalta, and lacustrine deposit mainlyexisted in Qingdong area.The reservoir sand bodies maily concluded channel sand,delta frontsheet sand, fravity flow waterway and so on.Based on the observation of slices, SEM,mercury penetration, poroperm characteristics, thefeature of the samples from cores, such as petrologic compsition, diagenesis and hydrocarbon porevolume was discussed. It was concluded that the sand style mainly consisted of arkose, lithicarkosic wacke, and they universally experienced a seres of diagenesis. One of these diagenesiswas dissolution that was the maily reason of secondary porosity. The control factors of quality ofreservoir mainly concluded sand form, diagenesis and tectonic movements. The quality ofreservoir and favorable zones were valued according to the analysis of zone of depth, lithogenousphase,and stone type, etc.