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Study On The Remaining Oil Distribution And Reservoir Fine Description In Yang Jiaba Oilfield

Posted on:2010-12-10Degree:DoctorType:Dissertation
Country:ChinaCandidate:J R WangFull Text:PDF
GTID:1220360272987934Subject:Oil and gas field development project
Abstract/Summary:PDF Full Text Request
The Yangjiaba oilfield is located in Jinhu county of Jiangsu Province and is a small layered complex fault block oilfield mainly controlled by faults and noselike structure, partly affected by lithology. The oil-bearing area is 3.8 square kilometers with geological reserve about 5990 thousand boe tons. The average porosity is 18.2% and permeability 23.6×10-3μm2. The oilfield was put into production in 1988. By adjusting, optimization, layer subdivision and fracturing, oil production rate was more than 1.0% with annual production of 6 to 8 thousand dons for 6 straight years. Now the oilfield came into high and extra high water-cut stage. Some wells are flooded heavily caused by uneven development of fractures and nonhomogeneous characteristics in the oil-bearing formation. The production slashed and water cut is rising.Based on macro and micro structure study to Yangjiaba oilfield, the forward micro structures are divided into micro fault-nose, micro nose, micro bench and micro fault block whose origin and effects to the remaining oil are analyzed. Through research to the characteristics of sedimentary petrography, lithology facies and electrofacies, the sediment system is defined as the river deltaic to shore-lacuatrine facies which are divided into 10 micro facies. Different facies are characterized with remarkable physical property. The underwater distributary channel has the best physical property, while sheet sand and beach sand take the worst place. With fractal geometry, the qualitative evaluation is made to the discipline of fracture development,that the greater fractal dimensions are accompanied with more fractures, and vice versa. With mathematical statistics, Gini ratio and macro heterogeneous composite index, horizontal heterogeneity which is controlled by facies is severer than lateral heterogeneity and sheet sand has the seriousest heterogeneity. By modeling stochastic method, fine geologic model is built up. A series of remaining oil distribution research have been set up, including log interpretation of swept layer, field testing, dynamic analysis, numerical simulation. Laterally, the remaining oil normally enriches in beach bar and mouth bar microfacies. Vertically, the remaining oil normally enriches in main layer with large oil-bearing area, missed non-main layer, and top layer of thick reservoir. With the newest geology research results and dynamic analysis, the geological factors and reservoir engineering factors are defined which provide evidence to enhance the reservoir development effect.
Keywords/Search Tags:Remaining oil, Reservoir description, Sedimentary facies, Heterogeneity, Yangjiaba Oilfield
PDF Full Text Request
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