Multi-parameter comprehensively identifying sedimentary facies

A method for identifying the sedimentary facies is proposed. It can be described as follows: first, the single well sedimentary facies of core-wells are divided according to the depositional features and the logging curve pattern in the studied area. On the basis of the division, the sample databases of sedimentary facies are built up. Next, the important reservoir parameters used for identifying sedimentary facies are checked out, and the distribution patterns of the reservoir parameters of different sedimentary facies are obtained using statistic method according to the sample databases. Finally, a multi-parameter identifying equation is established from all the parameter distribution patterns of different sedimentary facies, and it can be used to identify the depositional facies of other well intervals. The multi-parameter identifying sedimentary facies method has the advantages of both the traditional methods and the statistical methods. It uses the recognition model established by the features of the known sedimentary facies for identifying unknown sedimentary facies. As an example, this method is applied in Zaonan oilfield, Dagang. Shale content, the thickness of single sand body and the shale content in the sandstone are selected as the reservoir parameters. The depositional facies of 13 layers of 321 wells are quick and accurately identified.