Study On Architecture Of Fluvial Reservoir And Water Flooding Simulation

Chengdong Oilfield is located at ChengZikou in north of ZhanHua sag. It is dividedinto east area and west area by cheng-21fault. The structure is high at east and low at west inresearched west area. The oil-water contact of the aim reservoir which is8-10sand units ofGuantao oil bearing group is very complicated. During the production years, some problemsremain to be solved, including the poor basal research, lack of understanding to reservoir, partof oil bearing layer which has not divided more, short of knowing about oil-water distributionby sedimentary structure.The aim reservoir, which is the west area of Chengdong Oilfield, mainly developsbraided river sedimentation deposited during flood period and dry period. Its reservoir has awide range of development above the burial hill and presents inherited property. The sandbody of braided river has a large scale. The channel bars are distributed among the vastbraided channels and the content of sand is higher than that of mud in the section plane. Theflood planes are sporadically distributed in the side of the channels deposited for severalperiods. From10to8sand units, the growth rate of the tolerable space for sediments is higherthan the accumulation rate. Thus, retrogradation is formed.Through the research on the information of the area’s background, drilling core, geology,exploitation, well logging and the principles of fluvial sedimentology and present deposition,computer technology, log interpretation, experimental technique of water displacementimitation and core analysis are all applied in the researched area. Based on the formationcompartmentalizing and paralleling, the studies of reservoir architecture, heterogeneity andthe distribution of remaining oil after water displacement are carried out. Making use ofarchitecture analysis, the researches on braided river reservoir are conducted. Firstly, theinterface of the braided river architecture is defined. Secondly, the types of architectureelements are divided and the character of each type is summarized. Thirdly, the standards ofarchitecture elements division and identification are fixed. Fourthly, under the control ofarchitecture elements, the braided river reservoir distribution model is established. Fifthly, theheterogeneity model is established after the research on the braided river reservoirheterogeneity. Based on the architecture model and heterogeneity model, water displacement heterogeneity model are designed. Then, the genetic type and distribution pattern ofremaining oil can be studied by using water displacement imitation experiment.