RIASSUNTO
Abstract
Having a long-term plan to maximize economic recovery of hydrocarbons whilst delivering reserves today is at the core of sustainable development in EP Business Plan Priorities (especially reserves replacement ratio and growing the resource base).A typical hydrocarbon maturation funnel, which is a graphical representation of existing projects underpinning the maturation of volumes gives insight into the maturity of the projects, sustainability of production, reserves replacement over time and availability of maturation options. At reservoir or field level they provide information on the ultimate recovery that is currently expected and highlight which recoverable volumes are not yet underpinned by projects.
Continuous refreshing of the maturation funnel can never be overemphasized and the success of this refresh is determined by the quality and number of opportunities generated over time that gives an accurate perspective of the full life cycle recovery expected from the reservoir, rolled up to the field level. The objective of an effective opportunity generation process is to clearly identify new projects and provide answers to certain pertinent questions like; a) are all the volumes in this funnel supported by projects? b) what reserves replacement does the funnel yield in the next 5 years? c) what ultimate recovery does the funnel yield? d) What type of recovery processes will be employed now and in the future?
Field A was used as a case study to test the efficiency and impact of this process with special reference to production sustenance and life cycle recovery optimization. A Portfolio Review of fields in the asset was held and this prioritized Field A among the top opportunities for further development. Seventy percent of oil volumes in the asset reside in 11 top fields and field A was a part of this category. The field has an expectation STOIIP of 1602.2 MMstb with ultimate recovery of 520.9 MMstb (RF 33%). The cumulative production from the field as estimated was 300 MMstb and expectation reserves was 89.5 MMstb, meaning an opportunity gap of 131 MMstb remains for which projects could be identified.
The field was selected for a Technical Review exercise due to its large STOIIP, low UR, depletion rate and decline in production. The review outcome identified gaps in data availability and volumes. A total of 40 opportunities were generated to mature70.1 MMbbl and as such optimising the life cycle ultimate recovery. This paper will highlight the process of efficient opportunity generation, its gains and effect on life cycle recovery using field A as a case study.