Tracking of Oil Water Contact in a Barail Main Reservoir

To supplement the current understanding of the reservoir and also to increase the confidence level in decision making, an understanding in the variation of Oil Water Contact is very much important. In this paper, a study of an integrated and efficient methodology for establishment of complex Oil Water Contacts in Barail Main Sand (water drive reservoir) for a part of one oilfield of Upper Assam Basin has been discussed. The Barail Formation which is the main producing reservoir exhibits unique behaviour in terms of fluid distribution. The aim of the study is to map the movement of Oil Water Contact with respect to time and production in the study area. The study is mainly based on the structural contour map drawn based on the open hole log data of drilled wells in different time frame throughout the development of the study area. Using Oil Field Management software a cross section had been prepared taking Oil Water Contact as base among the selected wells to track its trend in these wells of the study area. The present study shows that Oil Water Contact is disturbed upon the start of production and sensitive to the rate and volume of withdrawal from localized area. Aquifer is very active and vertical sweep efficiency in the reservoir is very good due to its reservoir properties which resulted a small transition zones as it is evident from the open hole logs of the wells drilled in different time span. The study also shows that as a result of the thinning of oil column and sand incursion owing to the high drawdown in the study area, the tracking of movement of Oil Water Contact is found to be very important.