East African Scholars Journal of Engineering and Computer Sciences Abbreviated Key Title: East African Scholars J Eng Comput Sci ISSN: 2617-4480 (Print) & ISSN: 2663-0346 (Online) Published By East African Scholars Publisher, Kenya Volume-3 | Issue-6 | June-2020 | DOI: 10.36349/easjecs.2020.v03i06.12 *Corresponding Author: Paul Amihere-Ackah 74 Research Article A Field Development Plan for Cat shill Brown Oilfield in Trinidad Utilizing Water flood Simulation Paul Amihere-Ackah 1 * and Benjamin Makimilua Tiimub 2 1 Department of Chemical Engineering, Faculty of Engineering, University of the West Indies, St Augustine Campus, Trinidad and Tobago 2 Department of Environmental Engineering, College of Environmental and Resource Sciences, 310058, Zhejiang University, Hangzhou-China Article History Received: 18.05.2020 Accepted: 09.06.2020 Published: 15.06.2020 Journal homepage: https://www.easpublisher.com/easjecs Quick Response Code Abstract: The identification of new oil fields onshore Trinidad and Tobago has become almost impossible. Therefore the possibility of producing by-passed hydrocarbon accumulation from the matured Catshill field was determined through a holistic field development plan using waterflooding. The field development plan involved detailed reservoir characterization study. There were two phases of development plans considered. (1) Injecting water above the bubble point for a new field development (2) Injecting water below the bubble point using existing field data. Effective use of petrel aided the building of all geological maps of the area. Maps generated in Petrel were exported to Computer Modelling Group (CMG) for detailed reservoir simulation study. The estimated oil in place was 27.541MMSTB. Primary production yielded 27.2% recovery factor which was less than half of the oil in place. Implementation of water injection above the bubble point pressure yielded 49.8% recovery factor when produced for 10 years. By injecting water below the bubble point pressure using staggered line drive pattern, the recovery factor was 39.4%. It can be concluded that developing a field using waterflooding is best when pressure is high. However, there could still be significant recovery (39.4%) when field is matured. Economically, production will not be profitable if the oil price goes below 46 US$/bbl. Keywords: Field development; Reservoir; Matured oilfield; waterflood simulation; Catshill. Copyright @ 2020: This is an open-access article distributed under the terms of the Creative Commons Attribution license which permits unrestricted use, distribution, and reproduction in any medium for non commercial use (NonCommercial, or CC-BY-NC) provided the original author and source are credited. INTRODUCTION Oil field development is a multi-disciplinary approach that comprise of parameters relating to geological and structural characteristics, reservoir characteristics through to operational scheduling and economic analysis and evaluation (Mezzomo, C. C., & Schiozer, D. J. 2019). Reservoir lifecycle starts at exploration and discovery (Alqahtani, M.H. 2010). When discovered it is produced until it ends at abandonment (Alqahtani, M.H. 2010). Many discovered field are ever diminishing and matured (Blaskovich, F.T. 2000). Increasing water and gas production, decreasing pressure, and aging equipment are indicators of field maturity (Babadagli, T. 2007). Trinidad discovered oil in 1876 but commercial production only began in 1908 (Sinanan, B. et al., 2016). Trinidad and Tobago has record in petroleum sector for more than one hundred (100) years with cumulative production of more than three (3) billion barrels of oil. According to Ernst and Young (2013) proven crude oil reserves as at 2013 were estimated at 728 million barrels a publication by the Energy Information Administration (EIA). This indicates that the possibility of fields becoming matured is high. A holistic development scheme for recovering oil from these matured fields is much necessary. Among such fields in Trinidad is the Catshill oil field. According to the Ministry of Energy and Energy Industries (2009), the first well drilled in Catshill was in November 1950. The Catshill field is divided into two main parts, the Northeast and Southeast, each part of the field was discovered by the drilling of CO-3 and CO-5 wells respectively in 1952. The two subdivision of the field is marked by a major fault known as the Boomerang fault which has a marked difference on either side with respect to biofacies and lithofacies. This research evaluates the Southwest of the Catshill Field. The Southwest of the field produces from the k-sand commonly known as the CO-30 sand. Most of the oil production comes from the sands that are of Upper Miocene age (Koldewijn, B.W. 1961). The field has been in production for more than 40 years with a decrease in pressure and production