Publications

In Rimau Block, several oil and gas fields had been discovered in 1973 and have been producing since 1986 from various type of reservoirs. Peak production period of the fields had been passed decades ago as all main reservoirs are already opened and depleted. In order to maintain mature field; production, it is very essential to identify prospective layers that have never been produced. However, identifying prospective layers is quite complex process as there are many factors to take into account , such as water saturation, porosity, permeability, net thickness, pressure, oil show, gas reading, well correlation, and also its production history. A new approach is introduced to these mature fields, in order to revisit the 3rd grade layers that were previously categorized as non-pay due to low quality reservoir and highwater saturation interpretation. The main steps of this approach are: identify near proven productive zone (above and/or below), put the focus more on mudlog data rather than petrophysics analysis, integrate the static and dynamic data, and perform stimulation feasibility analysis. This paper will discuss the reservoir problem identification and analysis, methodology to redefine prospective layer, and the result of reservoir optimization initiative using the mentioned concept. The initiative successfully generated 180 BOPD initial gain from three pilot workover program and more prospective layers have been identified for workover candidates. In conclusion, this approach is a proven concept and can be practically applied in other mature fields.