F Field THN is one of the mature oil fields which active producing recently in Sumatera region. The Exploitation is mainly targeted on Muara Enim Formation which is deposited in depth of 650 mKB to 800 mKB. This formation is located in South Sumatera basin Palembang sub – basin. Until this time, there have been 65 wells drilled and some them had been suspended due to be unproductive and producing water in high rate instead of producing oil. The goal of this project is to define potential zone ini Muara Enim Formation of field THN in form of bypassed oil zone. Bypased oil zone is a type of hydrocarbon reservoir which neglected before and has not yet been developed until now. To define the location of bypassed oil zone is an interesting challenge where the available data especially the logging data were recorded in years ago and very limited. So that, it is very necessary to be very careful in analyzing the logs and having a strong basic of petrophysics to maximize the utilization of each available log. One that being used for this project is method of unconventional combination logs. This method is based from the core of petrophysics. By having the qualitative and quantitative analysis on 2 wells, THN-56 and THN-38, it is concluded that there are some potencies of bypassed oil zone in field THN that have been verified by several supporting data such as mud log. Through the volumetric reserve calculation, These 2 wells still have potencies of 70 thousands barrel oil estimated that can be produced