Publications

This paper describes the application of cased hole resistivity measurement during a ten wells monitoring campaign in waterflooded Kaji Semoga field, Sumatra, Indonesia. The objectives of this project are to identify oil remaining reservoir intervals, optimize completion design and to provide the critical hard data to predict current oil saturation condition in water flood and carbonate environment.This project describes the use of the cased hole formation resistivity in a single oilfield, how it contributes to production enhancement and optimization, and brings valuable data for simulation and field production management strategy. Critical factors for success included committed team, proper log interpretation and a fast learning curve based on early results.Saturation monitoring and hydrocarbon depletion evaluation in moderate salinity waterflood can be accomplished by using cased hole formation resistivity. The cased hole formation resistivity minimizes the uncertainties associated with the borehole environment and provides a deep resistivity measurement. Current saturation calculation risk can be reduced by comparing the cased hole resistivity with open hole resistivity measurement and using formation water salinity information. Potential changes in formation water salinity due to active water flooding mechanism can be taken into account to improve the final answer.Current saturation calculation is further developed using Simandoux equation based on the actual water salinity of the formation. This effort allows the team to design a production strategy, up to date field saturation distribution and better reservoir management. It also brings incremental oil gain by providing recommendations for workover based on the cased hole resistivity results.