Evaluation of IOR Potential within Kuwait

Abstract

Abstract Kuwait's production to date is characterized by large, massive reservoirs undergoing natural depletion with the help of strong natural aquifer drives. In a few fields, natural aquifer support is supplemented by pattern or peripheral waterflood. However, there has been no systematic attempt to define the Improved Oil Recovery (IOR) potential within the country. This study is a first attempt to assess this potential. The study considered 10 IOR displacement processes, suitable for long-term implementation within Kuwait. These processes included waterflood (including chemical floods), gas injection processes, and thermal methods. The study did not consider techniques based purely on well stimulation or infill drilling (e.g. cyclic steam injection, or horizontal well development); the potential for these techniques is already well understood and considerable data already exists for planning around these options. The study focused on screening reservoirs and identifying IOR processes for further study. The screening was in two parts. The first part was an evaluation of process suitability for all reservoirs. The second part was a ranking of IOR opportunities by reservoir. In total, over 800 process/reservoir combinations were evaluated. The evaluation process made use of various industry criteria; however, these were modified to better reflect conditions within Kuwait. After screening for suitability, the reservoirs were ranked in importance for future study. This ranking included: incremental oil recovery, crude quality cost per barrel and urgency (timing). This ranking will be used to direct resources at particular projects for further study and, if positive, future implementation. Key technical contributions of this work include: data evaluation techniques, consistent ranking of reservoirs with varying degrees of risk, development of scoping economic models for preliminary project assessment. Introduction Improved Oil Recovery (IOR) methods, as defined for this study, consist of processes in which an injection fluid is used to improve the recovery of oil from a hydrocarbon reservoir. In other words, IOR includes the following processes: Waterflood, Miscible Gasflood with Hydrocarbon, Carbon Dioxide, or Nitrogen as an injecting, Immiscible Gasflood (Hydrocarbon), Enhanced Waterfloods (Surfactant, Polymer, or Alkaline), Steamflood (including Steam Assisted Gravity Drainage) and In-Situ Combustion. Most Kuwait reservoirs are currently under primary depletion, with no IOR. This is due to a variety of reasons, primarily because of strong natural aquifers and the relatively early stage of depletion. A few reservoirs in North Kuwait are in the process of implementing a sea-water injection process, and a few in West Kuwait are making use of dump-flooding to enhance the natural aquifers. It is expected that many reservoirs would eventually benefit from the application of IOR methods to increase oil production/reserves and extend field life. This work was undertaken to help focus attention on those fields and IOR methods, which look most promising and warrant further study.