Abstract:

Description of the geometric model of the fan delta single stage fan is the key geological technology which solving the development of Haita oilfield. Regarding high-resolution sequence stratigraphy and modern sedimentary theory as the guidance, we identify 3 long terms, 4 middle terms, 6 short terms, and 53 super short terms (equivalent to single sand body) base-level cycles in N2 of Nantun Group in Bei 301 region Huhenuoren oilfield. We also establish the monosandbody rank high-resolution sequence stratigraphic framework in encrypted development zones of Haita basin for the first time. The study of sendimentary microfacies shows underwater distributary channel and microfacies for river mouth bar which are full of favorable sandbodies mainly develop in the little accommodate space that near the turnaround serface of SSC3,SSC4,SSC5 and SSC6. The width and thickness ratio for the single underwater distributary channel is generally between 50∶1 and 200∶1 ,the average value is about 85∶1. With the decreasing of the base level, the width of underwater distributary channel is increased,and the thickness is thickened, and the width and thickness ratio is increased. With the rising of the base level, the width of underwater distributary channel becomes narrower and the thickness is decreased,and the width and thickness ratio is decreased.The distribution area and thickness of river mouth bar has a certain positive correlation. The radius and thickness ratio is between 60∶1 and 120∶1, the average value is about 90∶1. This research established the industrial drawing of monosandbody rank sendimentary micro-facies in Haita basin for the first time, described geometry characteristic of the main monosandbody and provided the geological basis for comprehensive development.

Key words: high-resolution sequence stratigraphy, Haita basin, fan delta, monosandbody, geometry