Coupled Surface/Subsurface Simulation of an Offshore K2 Field

Abstract

Modern simulation capabilities were recently applied to the K2 Field to help define a risk-reducing phased development. This integrated study relied heavily on new advances to handle complex fluid behavior, derive a history match, resolve future behavior of sub-sea wells, and seamlessly review economic metrics.Simulations used tightly-coupled surface and subsurface calculations to capture and stabilize the interaction of surface facilities with the reservoir. This robust and rigorous approach improves upon previously reported techniques in which subsurface flow calculations are only loosely coupled to the surface network. Fluid characterization involved a single equation of state with multiple distributed component sets in reservoirs and compositional mixing within the surface network. Super-critical initialization was used to represent an unusual compositional transition from a highly undersaturated oil rim to an undersaturated gas cap. History match parameters included reservoir, facilities, and well properties.A host of development options involving artificial lift (AL), additional wells, miscible gas injection, and water injection was evaluated for economic value through an optimization-under-uncertainty approach. This assessment guided a multidisciplinary project team to detail a short set of developments for highest consideration in a common situation where the complex interactions among the reservoir, wells, outflow network, and facilities, makes an intuitive solution inaccessible. Although the four geologic models used were considered adequately diverse for the study, further value lies in broadening the geological uncertainty and hence the range of possible outcomes.While a relatively new application in deepwater fields, AL is recognized as a technology to extend producing life for mature fields and enable production from challenging plays such as the Gulf of Mexico lower Tertiary. Few case studies addressing such situations are available. The presented workflow may be repeated on assets with significant outflow performance drivers -assets that would benefit from modeling and resolution of complex surface/subsurface interactions.

Desenvolvimento e gerenciamento de reservatórios de petróleo com foco na modelagem integrada com sistema de produção

“…Além disto, se o tempo gasto na simulação da rede de superfície é relativamente pequeno se comparado ao tempo gasto na simulação de reservatório, isto ocorre pela simplicidade do caso (poucos poços, uma rede de escoamento simples etc.). Dobbs et. at.…”