FORMATION EVALUATION IN HAMRA OIL-FIELDBY USING WIRELINE LOGS

Abstract

Formation evaluation can be performed in several stages such as during drilling, after logging as detailed log interpretation, and core analysis in the laboratory, etc. This study shows the formation evaluation using wireline log data of hamra oil Field (MH-1). Lithology has been identified from Spectral, Natural Gamma Ray logs and SP where hydrocarbon bearing zones are detected by resistivity and lithology logs including cross checking of porosity logs. The shale volume is estimated from Gamma Ray and True resistivity methods, respectively. Porosity has been estimated from single log methods as well as from Neutron-Density combination formula and Sonic log. Formation water resistivity is estimated from Inverse Archie’s, Rwa analysis. The Archie’s, Indonesia and model have been used for water saturation estimation. According to log data analysis, there is baring sand zone well where small mud cake is present within oil bearing sand zone depth interval. Lithology is laminated shale and silt. The average gamma ray value and resistivity ranges are 49-102 API and 11-23 ohm-m of reservoir sands. The shale volume is about 20and percent from Natural Gamma Ray and True resistivity methods of thick sand with 14.2 meter reservoir thickness of bantiu. Average formation water resistivity for virgin zone is 0.04 ohm meter. This oil bearing reservoir sand porosity and permeability quality is good. The average water saturation is 0.041 percent using aforementioned model, this water saturation is more reliable for estimating reserve estimation and future reservoir analysis of this formation