Research On Remaining Oil Description And Redeveloping Measures Of PI1-4Oil Layer After Polymer Flooding In Nanwu Area

PI1-4oil layer carry out polymer flooding in Nanwu area in2005, that has now gone intothe subsequent water flooding stage. By2011August, recovery percent of the PI1-4oil layeris only50.13%,529.11×104tons oil remained underground, and so continuous potentialtapping is very necessary.The structural model of subdividing layers, sedimentary facies model and faciescontrolling property models of the test area were built based on fully using the logging andseismic information of Nanwu area, combining digitized sedimentary facies data, using thegeologic modeling software Petrel and borehole-seismic comprehensive method. The refinedhistory matching of separated-zone water injection has been performed by using thenumerical simulation software Eclipse. The history match indexes include OOIP, compositewater cut and single well water cut, etc. The numerical simulation model was refined based onthe history matching.The remaining oil distribution of all kinds of plane single sand body and longitudinal oilzone in test area after polymer flooding has been calculated and analysed based on refinedhistory matching. And the causes and types of remaining oil in test area were summarized anddifferent types of remaining oil were quantized. On the basis of field experiment of polymerflooding, the effects of its development were systematically analyzed in this paper. It includesthe performance characteristics of polymer flooding, appraisal of the development project bypolymer flooding, and affecting factors etc. It can provide a theoretical basis for the rationaldevelopment of the block.Potential tapping measures for different types of remaining oil in the test area wereproposed by combining geologic characteristics of test area. The effects of enhancing oilrecovery for these tapping potential measures include high angle wells, improved wells,profile correction and water plugging were given, and carrying out economic evaluation. Thepaper provides favorable basis for quantizing remaining oil, research on tapping potentialmeasures at present and further development and deployment in test area.