Methods Research On Reservior Classification Of Chang-8Reservior In Zhenbei Area

Reservoir classification is to sequnerce the exploration block reservoir, it provides the basis for oil-gas exploration. With the exploration development, the production of high quality oil and gas reserves decreased year by year,to the contrary, the production of low permeability reserves accounts for the proportion is increasing year by year, it has become the main resources of China’s oil and gas reserves in the present and in the future. The reservoir classification of low permeability oil and gas exploration is becoming more and more important, it not only relates to the early evaluation of reservoir, but also provides important basic datas for the deployment and planning.Zhenbei area is one of the main reservoir for increasing the production in Changqing Oilfield in recent years, the reservoir is the type of low porosity、low permeability and strong anisotropy. the uncertainty about Reservoir classification restricts the reasonable technology policy formulation and scheme determination.we need to research reservoir classification for scientific, reasonable, efficient development of oil reservoir and improving the ultimate recovery efficiency.The article take246block of chang-8reservior in zhenbei area as the research area. Based on comprehensive analysis of geologic report, logging, borehole log, well testing and experimental analysis of data, we analysed the aim of reservoir character, relationship of lithology、electric nature、physical property、oil cut,logging response characteristics, and established reservoir qualitative, quantitative evaluation model and deciphering standard. With the precise calculation of reservoir parameters, we study the methods of reservoir classification, and then compiled the corresponding logging interpretation and reservior classification program, we procesed and resulted verification. The main achievements and recognition include the following:1. Studing geologic report, Lithologic characteristics, grain size characteristics, pore structure, physical property characteristics of reservoir characteristics, relationship of lithology、electric nature、physical property、oil cut to lay a good foundation for the follow-up evaluation and reservoir classification.2. Focus on the logging responses of reservoirs, we had probably understanding about logging curve value distributions of oil layer, oil-water layer, water layer, it contribute to reservoir classification.3. Combined with the block characteristics and reservoir characteristics of log response, we established the chart about the qualitative identification of reservoir fluid properties,it can be roughly identificate reservoir fluid properties. 4. Based on the movable fluid analysis method,we established the parameter calculation model of the block as follows:①Clay content calculation model;②carbonate content calculation model;③Porosity calculation model;④permeability calculation model;⑤Water saturation calculation model;⑥irreducible water saturation calculation model;⑦residual oil saturation calculation model;we used the logging interpretation chart for model validation and had good results. then established the standard of the quantitative interpretation.5.Based On the interpretation method research and interpretation model,we studied the the main parameters which effct reservoir productivity, and constructed judgment matrix, calculated the maximum eigenvalues and eigenvectors, and then through the consistency test,after that,we analyze the weight of these parameters by analytic hierarchy process, combined with the existing reservoir classification standard, then explore the reservoir classification method.6.Combined with the porosity, permeability, oil saturation, effective thickness resistivity, acoustic parameters,we explored the method about reservoir classification,these include:①Fuzzy comprehensive evaluation②Using well logging curve shape for reservoir classification;③Using the change law of the parameters for reservoir classification7.Based on the theory about fuzzy comprehensive evaluation, we compiled the corresponding log interpretation program, interpretated the well logs,and classificated the reservoir, the effect is good.8. The work done when we use fuzzy comprehensive evaluation to classify reservoir is follows:①.Perferred the main parameter for the reservoir classification;②.Get the weight of the main parameters in reservoir evaluation;③.Set up the standard of reservoir classification and evaluation;④.Classify the reservoir...