A Research Of Logging Evaluation Method For Water Flooded Layer Of L Field

L oilfield as the earliest developed oilfield in China has entered the late low production "three highs" development stage,in which oil-water relationship was complex and remaining oil fragmented highly,so oil horizon exploitation difficulty is increasing gradually. And the hybrid new and old logging series, mismatched logging data, basic research is weak. Currently, qualitative analysis is mainly and quantitative calculation is complementary in the logging interpretation of water flooded layer of L oilfield;and in quantitative interpretation,interpretation coincidence rate of water flooded layer is not high. Therefore, it is urgent to carry out water flooded layer logging evaluation research for improving the logging service ability in development.Long-term waterflooding development makes the fluid properties, pore structure, rock physical and chemical characteristics and oil-water distribution in oil layer changed to some extent. Through the study on block reservoir petrophysical analysis, rock mineral analysis, pore structure analysis, rock electrical characteristics experiment, the analysis of characteristics of seepage, and the comprehensive analysis of various materials oil content description data of the logging, testing, test data, the water analysis data, the historical development data and geological data, detail geological condition and the overall development situation of the research block have been grasped, which laid a foundation for the following water flooded layer logging evaluation.M reservoir of L oilfield is a whole set of low permeability block sandstone reservoir. On the longitudinal lithology and physical property of three sand group features of slightly different, so considering their characteristics respectively that reasonable parameter interpretation model is established.Analyzed geological characteristics,and summarized the parameters change rule of water flooded layer.For the actual characteristics of L oilfield water flooded layer, combine with theoretical analysis, we have summarized the logging response characteristics of water flooded layer, put forward the water flooded layer qualitative identification method:spontaneous potential baseline shift method, resistivity drop method, the original resistivity inversion method, pattern recognition method.The shale content, porosity, and permeability models are established based on rock core analysis data and log data of the research block; the water saturation interpretation models are set up by using litho-electric experiment data and water analysis data; residual oil saturation, irreducible water saturation, oil-water relative permeability and water production rate models are set up by using water flooding experiment data and oil-water relative permeability data. Through the actual data processing, the porosity, permeability,residual oil saturation,and irreducible water saturation accord well with those of the several parameters analysized by core experiment.On the basis of established various reservoir parameters log interpretation model and evaluation method, combined with test oil and water flooded condition data, quantitative classification standards of water flooded layer water level is established by using water production rate and oil displacement efficiency.