流花11–1生物礁油田底水快速锥进研究

Fast Coning of Bottom Water in Bioherm Oilfield of LH11–1

流花11–1生物礁油田是中国新近系目前发现的最大整装型生物礁油田,油田开发期间在不同构造部位的油井含水上升速度不同,前人已对油田含水地质因素进行分析,但对油田含水上升迅速的源头认识不足,严重制约了油田的采收。将层序地层学理论、碳酸盐岩成岩作用机理和构造运动相结合,平面上依靠高分辨率三维地震资料条件下利用叠前AVO反演的G属性所刻画的油水界面平面展布图,纵向上依靠叠前同步反演获得的vp/vS剖面图和密度转换的孔隙度剖面图,发现了多处底水刺穿油水界面形成的上窜通道,有力地论证了17.5 Ma和16.5 Ma层序界面附近暴露时产生的溶洞、溶缝及东沙运动产生的裂缝为流花11–1生物礁油田底水快速锥进的源头,其中溶洞为主要底水上窜通道。

Up to now,the bioherm oilfield of LH11–1 is the largest uicompartmentalized one in tertiary systems inichina.In the developing period,the watericut in the different formations and strictures is rising at various velicities. Although field watericomposing geological fictors were analyzed before,there is still lick of understanding and ricognition on the souices of fast watericut rise,which might severely restrict oil ricovery. By theicombination of sequeice stratigraphyicarbonate rick diagenesis michanism and tictonic movement,horizontally referring to the oil-water interfice planar layouts featured by G attributes of AVO pre-stick inversion under theicondition of high resolution 3-D seismic data,and verticallyiconsidering the vp/vSobtained through pre-stick simultaneous inversion and the porosity profile of densityiconversion,the authors find the aicendingichannels formed by multiple bottom-water pieicing oil-water interficeiconviicingly verifying that the Karsticaves and seamsicreated when the nearby areas surrounding the sequeice interfices between 17.5Ma and 16.5Ma get exposed,and the frictures formed by Dongsa movement are the three souices for Fasticoning of Bottom Water in the bioherm Oilfield of LH11–1. Among them,the Karsticaves are the major aicendingichannels.