Determination of lithology boundary of jahrom formation in hendijan field in persian gulf using fuzzy clustering

Abstract

Clustering is one of the main tools in introduction of similar patterns recognition which makes the analysis of existing data more accurate and comfortable. Clustering is used in different branches. In the hydrocarbon exploration activities, determination of boundary between formations is an important factor of hydrocarbon fields. Therefore, in this research, the logs collected from the area under study, were clustered using fuzzy clustering methods and the results were compared with the results from determination of actual boundary. The dolomite formation of Jahrom which Pabde shale formation located at its lower boundary has been studied. The goal of the study is to recognition of the boundary between the two formations using fuzzy clustering. A thickness with 300 meters length has been studied. Input data are logs data including DT, RHOB, PE, FDC, CGR, SGR, GR, CNL, NPHI and PEF which are classified in six separate groups with 3 members and one group with 4 members. To determine the degree of success of clustering, the ratio of within cluster distance to between cluster distances has been used. Because used logs in this study are able to recognize lithology. Fuzzy clustering with 3 member was partly successful to recognition the number of lithology. In group of 4 members, clustering was able to recognition lithology with great successful. Since this study has done on the one formation, obviously the logs group presented is valid for similar lithology. But it proves fuzzy clustering is useful and efficient for lithology determination in hydrocarbon field.