Determination of lithology boundary of Jahrom formation in Hendijan field in Persian Gulf using fuzzy clustering

Clustering is one of the main tools in introduction of similar sets and 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 also considered to be 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 present study is to recognition of the boundary between the two formations using fuzzy clustering. A thickness with 300 meters length has been studied. In addition, suitable logs for segregating the two lithologies are introduced. Input data are logs data including DT, RHOB, PE, FDC, CGR, SGR, GR, CNL, NPHI and PEF which are classified in six separate groups. The results from their clustering were studied in image format. To determine the degree of success of clustering, the ratio of within cluster distance to between cluster distances has been used.Final results show that fuzzy clustering in the presence of such a column is not able to present reliable responses and it is necessary to utilize this method in conjunction with other methods as a complementary method. This is not because of the use of a particular log, since the clustering was not able to illustrate an accurate or even rather accurate boundary determination in either of the groups, however, these logs have shown reliable responses while using other methods. It causes recognition of proper logs for clustering to be impossible during the study.

Keywords:

fuzzy clustering , Jahrom information , lithology , log