Mapping Chemical EOR Technologies to Different Reservoir Settings at Harsh Conditions in North Kuwait

Abstract

EOR is a key focus area for sustaining long term production and maximizing of recovery in Raudhatain and Sabriyah oil fields of North Kuwait (NK). NK oil fields consist of multiple stacked reservoirs containing both clastic and carbonate with challenging temperature and formation water salinity conditions for Chemical EOR. In addition to these harsh conditions, reservoirs have geological structural complexity, reservoir heterogeneity and aquifer strength settings. Kuwait Oil Company is putting large efforts into Chemical EOR (cEOR) maturation through two ongoing ASP pilots and polymer flooding maturation studies. Ongoing studies and preliminary piloting performance results revealed that different reservoir segments have different cEOR requirements for viable incremental oil opportunities on top of ongoing water flooding. An expansion strategy has been developed that provides a view on how to transition from pilot results to larger scale commercial implementation of cEOR for each reservoir segment. This includes front end elements, beyond conventional cEOR screening studies, injectivity, conformance control, inorganic scaling, facility impact and pattern configurations. For larger scale, many additional aspects such as water source, well location, phasing, logistics and impact of back production are important factors. For commerciality, there needs to be abalance between schedule, maximizing economic recovery, operability,availability of source water and costs. A holistic, structured approach has been established in defining production forecasts and life cycle cost estimates for ASP, SP and polymer development concepts screening for major NK reservoirs. The approach has allowed comparison between recovery methods and reservoirs which helped in defining an EOR expansion plan. The novelty in this EOR expansion strategy is in application of a structured and holistic approach to map viable cEOR technologies to different reservoir segments based on in-depth screening criteria. The methodology allowed generating "standardized" time bound forecasts and cost estimates for screening a range of viable mapped cEOR methods for a range of reservoir segments- facilitating like for like comparison.