New Oil Recovery from an Old Field: A Unique Case Study in Badr-1 Concession, Western Desert, Egypt

Abstract

Abstract Recent simulation study on the kharita reservoirs (Cretaceous) of the Badr – 1 field (BED – 1) reached to a doubtful under-estimated volumes of the Original Oil In-Place (STOIIP). With No Further Activities (NFA), predicted performance indicates total kharita reservoirs ultimate recovery factor will reach 53.5% of the STOIIP. All future sidetracks and new locations were terminated based on the limited remaining reserves as per the preliminarily simulation predictions. Because of the inconsistencies between the current average oil production rates and the huge volumes of cumulative oil produced, and combining the indicated pressure performance with the driving mechanisms, a reservoir management revision and performance review study deemed critical and necessary. This is also as per the indicated fingering / conning (stratification and permeability variations) taken place early upon start producing the wells. Top managements decided to carry out this assignment, with the objective of explaining and revealing the discrepancies and inconsistencies of the kharita reservoirs performance in BED-1 field. During implementing the different phases of this reservoir management assignment, focusing was given mainly to the understanding of the reservoirs performance rather than just obtaining a History Matching (HM). Numerous conventional and non-conventional approaches and commonly / uncommonly practiced techniques were applied. Considerable increase in the STOIIP was eventually concluded at about one and half times the under-estimated one obtained upon just history matching. This work highlighted the reasons behind the under estimated volumes of the STOIIP to be mainly related to the way with which the following issues were handled: (1) The historical average Reservoir and Boundary pressures, (2) The Aquifer strength, (3) Modifying the volumes of the cumulative gas produced, and (4) The existence of an initial gas cap that may dictate utilization of an average representative set of PVT data to account for variation of fluid properties with depth ?!. As per data availability, at the time of conducting this work, and based on the recent understanding of the reservoirs and wells performance, and also based on the results obtained from the applications of a great deal of traditional / non-traditional approaches, the remaining recoverable reserves are now estimated at more than two folds as first phase field development plans. This work shows also that remaining recoverable reserves could be doubled by the life-end of the reservoirs if: (1) the oil potential extensions to the southeast of wells BED 1-14 and well BED 1-3 are confirmed, (2) with continuous production from wells under high water cuts, and (3) with carrying out of phase two field development plans for infill drilling to recover the bypassed and/or the un-drained/un-depleted oil. The most appropriate methods to recover these remaining reserves were studied and identified and proved to be technically and economically justified. As a part of the results of the above work, two (2) sidetrack proposals, and five (5) new locations proposals and well BED1-13(H) re-entry proposal are strongly recommended for immediate execution. Results of the first well recommended and recently drilled (well BED 1-19) as per this work, has just come to confirm a new recoverable oil volumes could be added in BED-1 field.