Advanced Characterization Of Fuyang Oil Reservoir In Sheng22Block, Shengping Oilfield

The Sheng22block is located on the south dumping end of Shengping nosestructure which is in the central depression of Songliao Basin. During yearsof exploration and development, the whole block has achieved significant progress.However, there are still some geological problems during the production. For example,as one of the best blocks with relatively well reservoir physical property in the studyarea, the block has many wells with extremely high water-injection rate, resuting themajority of wells occuring water flooding at a relative early stage, which affected thedevelopment effectiveness. In order to improve understanding of reservoir geology,the paper carried out the research of advanced reservoir characterization. The aim ofthe thesis is to provide some suggestions for better development of the oil field in thestudy area.After analyzing previous researches and the newly collected data, the strata wasdiveided and correlated by following four principles:1) using sequence stratigraphytheory as primary guidance;2) using “cyclic correlation, hierarchical control, differentfacies with different treatments”as major criteria;3) using standard well as startingpoint and4) finally using marker bed as basic controlling factor. As a result, theFuyang oil reservoir is divided the into four oil groups, twenty-four small layers andfifty-one sedimentary units.And the sequence stratigraphic framework was establishedin the study area. Finally, by statistical analysis of drilling ratio and aggregatethicknees of reservoir sand in each sedimental unit, the main reservoir in the researchregion was idenfied and confirmed.Results from lithology, grain size and single-well profile phase analyses of coringwell show that the River-Delta traction-flow current deposits are the mainsedimentary types in this area. By detailed observation and analysis of exploratorywell information, log-phase model was set up by using sedimentary facies to calibratelog-phase. By comprehensive analyses, the sedimentary facies were indentified asthree major facies, seven subfacies and twnty-one microfacies in the study area. At thesame time, the vertical and horizontal distributions of sedimentary facies weresummarized by analyzing connecting-well and plane facies. Based on the well logging calibaraiton and drill cores analyses, the porosity,permeability, oil (or water) saturation models were founded. On the control ofsedimentary facies and geological conditions, the3-D geological model of four mainreservoir are made by applying Petrel modeling software and method ofgeostatistics and stochastic simulation. The geological model includ structural model,facie model and attribute model. All these models reflect geology characteristics ofthe main reservoir.Finally, both the geology reserves and theoretical oil-recovery-rate wereevaluated. Through geological analysis, it was found that residual oil distribution ismainly controlled by sedimentary microfacies, construction and development factors.For horizontal distribution, the residual oil is mainly in the thin sand body of the edgeor interlay of the river. For vertical distribution, it is in the top of the river. Forstructural distribution, it is in the fault angle and structural highs. As a conclusion, thetarget area for further oil development was forecasted in the study.