Research On The Reservoir Description And Geological Model Of Fan Delta Front Reservoir Of Shuanghe Oilfield In Biyang Depression

With the growth of exploitation time, the oilfield development of our country is facing with stem situation that transforms from easy areas to difficult areas, remote areas, from reserve-production primary balance to serious disequilibrium. The fan delta deposit is important oil-gas-bearing sandbody in Shuanghe Oilfield. Because the complicated internal structure, its reservoirs have different extents and geophysical features for each sedimentary microfacies, such as serious internal heterogeneities, rapidly variational facies characteristic. At the present time,Shuanghe Oilfield has entered the high water-bearing late-stage develop- ment, the exploitation is becoming more and more difficult, the using resource level and integral water content is becoming more and more higher, and the potential excavation is becoming more and more difficult. So, it is necessary to exactly know and predict the reservoir distribution characteristics and rules, to draw up the realistic strategic decision on exploratory development, to continuously optimize the development method. To accomplish above objective, some measures that carry out scientific reservoir description and build exquisite geological model must be taken to achieve the quantitative representation and heterogeneity depiction for the hydrocarbon reservoirs.On the basis of the actual fan delta reservoir exploration and development condition in Shuanghe Oilfield, by applying knowledge on sedimentology, sequence stratigraphy, deve- lopment geology, stochastic simulation, based on large amounts of logging, well boring cores, and outcrop data, and in combination with multi-discipline reservoir description technique, this dissertation systematically discussed the sedimentary characteristics of reservoir, the spatial distribution characteristics and evolutional law of sedimentary microfacies, the sequence stratigraphic characteristics, the reservoir property and heterogeneity, the stochastic modeling and reservoir evaluation and so on, built sedimentary microfacies and reservoir property model with many kinds of modeling method, constructed the comprehensive evaluation system for intended interval. Thus, it subtly described the reservoir characteristics in Shuanghe Oilfield, not only gave a push to the quantified, fineness study of reservoir, but also provided with reliable theoretical base for development adjustment in the oilfield. The paper mainly achieved the following results:1.By first applying knowledge on geology, logging, well boring, seismic data, and sequence stratigraphic analysis technics, this study carried out sequence stratigraphic analysis and contrast of the upper member of the third member of Hetaoyuan Formation in Shuanghe Oilfield, built fineness isochronic sequence stratigraphic framework.2.Guided by sedimentology theory, based on sequence stratigraphy, the sedimentary microfacies are partitioned, the microfacies mapping characteristics are described by single well and section facies analysis, the depositional model of different types of sandbody are established, and the evolutional law of sedimentary microfacies are systematically analyzed in the upper member of the third member of Hetaoyuan Formation in Shuanghe Oilfield.3.The first use of logging and core analysis data to research the reservoir property and microscopic, in-layer, interlayer, areal heterogeneity in the upper member of the third member of Hetaoyuan Formation, provide with data support for reservoir geologic modeling.4.Based on the thought of facies-controlled modeling, the paper first adopt many kinds of stochastic simulation methods, such as sequential indicator simulation, truncated gaussian simulation, sequential gaussian simulation, to build sedimentary microfacies and reservoir property model of the third member of Hetaoyuan Formation, and execute the model testing and optimization according to actual geological data and related information.5.First applying mathematical statistics and variograph analysis method to study spatial structure characteristic parameter of the sedimentary microfacies for the third member of Hetaoyuan Formation, quantificationally depict the spatial distribution characteristics of the reservoir.6.The dissertation established the criterion of reservoir evaluation for study area by applying the reservoir evaluation technique and sedimentary microfacies research results, first adopted the fuzzy comprehensive evaluation method to evaluate the part reservoirs of the third member of Hetaoyuan Formation in Shuanghe Oilfield.The research approach advanced in this dissertation has been verified by practical data of Shuanghe Oilfield, and the results can describe the characteristic of fan delta front reservoir spatial distribution accurately. Therefore, the results of this paper not only have great theoretical significance, but also have important role for practical application in Shuanghe Oilfield.