Reservoir Accumulation Regulation And Potential Analysis Of Nantun Formation In Beier Depression

As the largest depression in Hailaer Basin, Beier depression has abundant reserves of oiland gas resources and enormous contribution to field production. With facing the task ofincreasing oil production, although we have done a lot of research work in earlier stage, wehave not achieved very ideal development effect in development process. Research is urgentneed for reservoir accumulation regulation of the main layers in Beier depression, thenmastering time and space matching relation of forming conditions and analyzing reservoirmaster control factors.In this paper, we use the method of wells and seismic dividing and contrasting layers inBeier depression to achieve unified stratigraphic boundaries. Depression has the characteristicof zoned and segmented deformation. Clearing fault activity are four stages and each hasdifferent structural characteristic. The main distributed directions are nearly NE and NNE ofbasement faults in Nantun formation and it has closely relation with oil and gas. Bydissecting typical reservoirs of the main oil region in Beier depression, combined with thedistribution regulation of oil and gas on the plane and vertical, consider Nantun formationdeveloping block reservoir, broken nose reservoir, buried hill reservoir, stratigraphicunconformity screened reservoir, block-buried hill composite reservoir and so on. Observingand describing coring wells in study area, combined with the analysis of typical single wellphase, identify the depositional system is fan delta front-braided river delta front-meandering river delta front-lacustrine facies in study area. K1n2experienced TST and HST.K1n1experienced LST, TST and HST. K1n2and K1n1are the main layers of source rock. Fandelta, braided river delta and meandering river delta deposition are the most important phasebelt. Mudstone of K1d1is the regional seal. Mudstone of K1d2and Nantun formation arelocal seals. Reservoirs are mostly self-generated and self-stored combinations. The maincontrol factors of reservoir accumulation include source rocks controlling the distribution ofoil and gas, the distribution of oil and gas controlled by favorable sedimentary reservoirfacies belt and main fault zone controlling reservoir accumulation.Based on the evaluation principle of favorable areas, combined with the results of thetest oil in exploration area, optimizate two favorable areas for exploration which are southernpart of beixi slopes and north subsag west slopes and south surrounding of beixi subsag. Themain reservoir types are constructed reservoirs and composite reservoir. We propose threesuggested wells for each favorable area.