-
oa Reservoir Characterization of Fadhili Reservoir, Bahrain Field -A Case Study
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, GEO 2010, Mar 2010, cp-248-00435
Abstract
This paper describes a practical approach that led to improve the production from one of the unexploited<br>reservoirs in the Bahrain Field and increased its potential recovery. The Fadhili reservoir, a<br>middle Jurassic carbonate, is about 185' thick and overlain by tight Dhruma limestone, with an oil<br>column of 50-70' in thickness. The reservoir quality is good in the top 3 stratigraphic layers but<br>progressively deteorites towards the base of the reservoir. The low formation resistivities in the oil<br>bearing zones are attributed to the high formation water salinity, which makes the formation<br>evaluation difficult.<br>Vertical wells begin production with low water cut, which gradually rises to more than 95% during the<br>course of production. Six vertical wells drilled in this reservoir have produced 156 MMSTB of oil as of date.<br>Initially, based on the poor performance of the vertical wells, the Fadhili was thought to be a poor<br>prospect. However, a simulation model built to study the production behavior of the reservoir indicated<br>that the production potential can be increased if an appropriate well type is chosen for this reservoir.<br>Based on this study, to ensure maximum reservoir contact, a horizontal well was drilled, targeting the<br>top 10-20' of the oil column, to evaluate oil production potential of the reservoir. During the last six<br>months, this horizontal well alone has produced more than the total production of all the 6 vertical<br>wells put together drilled in the past.<br>The encouraging production results (high on oil/low on water) prompted a review of the geological<br>model and petrophysical properties of the reservoir for a) better reservoir characterization, b)<br>identifying reservoir flow units and c) estimation of reserves. This paper highlights the results of the study.