Carbon Dioxide (CO2) Enhanced Oil Recovery (EOR) process is most likely to become the preferred hydrocarbon recovery process in future in Abu Dhabi. The complexity and cost of implementing large scale EOR projects require the development of a detailed EOR strategy, clearly defined targeted objectives, a visionary work-plan (roadmap) and staged evaluation prior to full field commercial implementation. Abu Dhabi Company for Onshore Oil Operations (ADCO) is in the process of conducting the first Middle-East CO2-EOR pilot in an onshore complex carbonate reservoir.
This paper discusses the design and implementation of the first ADCO CO2-EOR Pilot Project which addresses key technical and business uncertainties and risks associated with CO2 injection in ADCO reservoirs in the future. The pilot was considered the best approach to evaluate feasibility of this EOR approach on a field scale in addition to other verifications through laboratory and simulation studies.
The project started with a company-wide screening study which attempted to identify both the most appropriate EOR option for ADCO reservoirs and the best reservoir candidates. Subsequently, an in-house simulation study was conducted to confirm the best identified candidate reservoir. The Roadmap defined studies required to fill the required data gaps. Advanced CO2-PVT, Asphaltene and SCAL studies were conducted to reduce the uncertainties related to CO2 injection. The pilot objectives and constrains were clearly defined at the early stage of the project. Challenges of obtaining the required CO2 volumes for injection were overcome.
A history matched compositional reservoir simulation model was used as an effective tool to design and optimize the pilot. Sufficient time and effort were expended in the pilot design and optimization in order to meet the implementation objectives in a timely manner. These include drilling of the wells, construction of the surface facilities, development and execution of the surveillance and monitoring plan and finally the operation of the pilot.
This paper outlines the design and implementation of the first ever Middle-East CO2-EOR pilot in an On-shore complex carbonate field in Abu Dhabi, UAE.