A Study On Internal Architecture Of Channel Sand In Meandering River

The reservoirs in LaSaXing oil field of Daqing is huge fluvial¨Cdeltasedimented reservoirs, with multi-layers, huge thickness and seriousheterogeneity. The oil field went into later development stage of high water-cutperiod, the distribution of remaining oil in space is highly scattered. Tertiaryrecovery has became the dominant technology to increase recovery efficiency inthis developing stage. According to mechanism, tertiary recovery increasesrecovery efficiency mainly rely on producing potential oil inside reservoirs, and itrequires accurate description of heterogeneity in reservoirs. By now, the reservoirdescription level is longitudinally accesible in sedimentary units and horizontallyaccesible in sedimentary microfacies, and currently heterogeneitycharacterization description is still unfeasible so far. Especially the study ofinternal architecture of single sand bodies in meandering stream channel,although many experts domestic and abroad have carried out academic study ofheterogeneity model from outcrop and modern fluvial sediment, but, they haven?ˉtdeveloped a set of reliable methods and technologies of reservoir description sofar.On the basis of domestic and abroad research and technical literature andresults of study, considering of the actual situations that the development ofmeandering stream sedimentary reservoirs have a typical characterization inmiddle areas of Saertu oilfield of Daqing, we suggested study methods and studystandards of internal architecture of meandering stream channel sand, and builttechnical system of inner heterogeneity description in meandering streamsedimentary reservoirs on the basis of sealed core-sampling data, logginginformation of close-space-wells, result of fine geology study, sedimentology,sequential stratigraphy, geological statistics, administrative levels analytictechnologies, structural element analysis etc.. Based on point bar sedimentarymechanism, and combine with point bar vertical sequences, type and compositionlateral bedings of point bar, we built the transversal sedimentary model of singlelateral beding and the sedimented rock model of lateral accretion of point bar, andform inner interlayer and combined relation of point bar, the description methodsof space distributing characterization and the internal architecture modelingtechnologies in meandering stream channel sand. The self-innovativetechnologies mainly are: the recognized methods of single point bar in complexsand bodies of meandering stream;the interlayer recognizing method about singlewell, parameter interpretation method, the interlayer forecasting method betweenwells of meandering stream point bar , and the internal architecture modelingtechnologies in meandering stream channel sand.The outcomes of this text can be applied in two typical blocks, which notonly improve the method and technology, but also can recognize internalarchitecture of meandering stream channel sand according to the recognition ofthe close-well-pattern conditions with 50m well spacing. It is an uniquetechnology to expose the inner heterogeneity of reservoirs,which has its ownvalue for popularization. The inner interlayer of point bar has a function ofseepage flow barrier, which controls the distribution of remaining oil inside zone,and it is necessary to study the internal architecture of meandering stream channelsand. The description of internal interlayer distribution in space of point bar inmeandering stream has a guiding functions for well pattern arrangement and wellspacing. Especially, the practice of horizontal well designation shows that thisstudy can provide guidelines for exploration of remaining oil in thick oil layerswith excessive high water-cut . At the same time, the outcome of this text canplay an important role for further study of modeling system of structural frame inthe channel sand reservoirs.