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Logging Evaluation Method For Carbonate Reservoir In Puguang Area

Posted on:2012-11-15Degree:MasterType:Thesis
Country:ChinaCandidate:H JiangFull Text:PDF
GTID:2120330338493439Subject:Earth Exploration and Information Technology
Abstract/Summary:PDF Full Text Request
The reservoirs in Puguang gas field are of marine strata mainly composed of carbonate rock, which possesses complex pore structure and strong heterogeneity, resulting in irregular change of the two key parameters used to describe the archie properties, and affecting the accuracy of saturation calculation. Furthermore, as a result of low formation porosity, the resistivity logging presents less sensitivity to the property of the formation pore fluid, adding difficulty to the identification of reservoir fluid. Based on the problems faced in the reservoir evaluation in Puguang area, this paper builds up a set of relatively perfect and effective methods of logging evaluation for fracture-vug type carbonate reservoirs in Puguang area by combining theory with practice systematically.Through further research on the geological characteristics of carbonate reservoirs, the effectiveness of the reservoir is demonstrated to depend on the coupling between matrix porosity, fracture and vug, and the coupling between pore space and throat. After sortation and generalization of the clues for carbonate reservoir evaluation, models of lithology identification and porosity and permeability interpretation for Puguang area are established, respectively.Based on the data of core analysis and well logging, we carry out the research on fractal characteristics and application technology of complex carbonate reservoirs. The core data are transformed into time series, and by using adaptive method of embedding dimension and scale-free zone, the correlation dimension algorithm is modified and meanwhile the basic relationship between fractal dimension of core and the cementation factor m is established. Then analysis the fractal characteristics of logging curves and build a function of the fractal dimension of logging curves and m through the fractal theory, and realize the expectation of calculating the value of m with logging curves. Combining with the core electricity experiment, the law of m and n is comprehensively analyzed, and also reasonable values are given for them. Finally a more accurate reservoir water saturation is obtained.From both macro and micro perspectives, the heterogeneity of the reservoir is studied. Using the fractal dimension of the logging curves, the reservoirs are quantitatively classified at the macro level, and with the fractal dimension of capillary pressure curve, the complexity of rock micro-pore structure is quantitatively identified. And the results show good consistency. A primary approach for fluid property identification is formed, mainly using the characteristic parameters with high resolution extracted from the logging curves and the multi-parameters extracted from the DSI. Thereby the gas or water layer can be effectively identified, improving the effectiveness of fluid property identification for complex carbonate reservoirs.
Keywords/Search Tags:carbonate rock, fractal geometry, cementation factor, saturation, reservoir classification, fluid property
PDF Full Text Request
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