Technical Research On Identifying Microfacies By Logging (Taking Example For The Major Reservoirs Of Yanchang Formation, Yanchang Oilfield)

Microfacies study is an important part of reservoir description, both in the exploration phase or stage in the development must be carried out reservoir sedimentary microfacies analysis. Because of the limited coring data, logging data in the study of sedimentary microfacies plays a important part. Traditional method is qualitativd,the result is large personal influence. With the development of log subject and computer technology, Logging facies quantitative automatic identification gradually popular, as now is an important content in modern sedimentray study.In this paper, based on microfacies research contents and requirements, starting from the actual data of the field to determine a reasonable technology routes on the microfacies research. Wavelet analysis techniques used in the stratigraphic division and establish a precise reasonable stratigraphic framework. Take use of a variety of sedimentary facies identification to divide the sedimentary facies in the study area. On this basis, take full use of the coring data, geological data,test data and logging curve, carried out coring microfacies analysis and electrofacies analysis for the coring well, established the relational database between the microfacies and the electrofacies. Based on the Grey Theory, optimizated a suitable system of the gray zone of microfacies analysis, such as the evaluation parameters, evaluation criteria and weights, which for non-coring wells carried out microfacies analysis, The analysis effects and the accuracy has improved significantly. Following the research idea as follows: single well y microfacies analysis - the sedimentary facies analysis of the trunk section - plane distribution character of sedimentary facies analysis. Summarized two microfacies models in the research area of FengHuChuan and YaoDian oil fields, studied the characteristics of the sedimentary facies evolution The research results laid a solid foundation for the oil field next development adjustment scheme The research technical routes has a certain reference for the adjacent area.