Knowledge based system for economics analysis and risk assessment of subsea development scenarios for small oilfields in the North Sea

The decision to develop a small (<100 mmbbls) oilfield in the UK sector of the Central/Northern North Sea requires a careful assessment of all aspects of the field development plan: the reservoir model (reserves and production profile), capital and operating costs, and the current economic climate (oil price, interest rates, tax regime etc). This paper describes the development of a knowledge based software package that allows a `quick look' assessment of the overall economics and risk profile associated with the development of small oilfields in this region. It is a modular system that uses a cost database, cost adjustment algorithms, cash flow analysis engine and simulation procedures to integrate and analyze the impact of reservoir and production characteristics, costs (capex and opex) and economic factors on the decision to develop such a field. The production system configurations considered by the system are: 1. an unmanned wellhead platform tied back to a third party platform for fluid processing/export, 2. an FPSO with oil export via a shuttle tanker and gas export via a tie-in to the existing North Sea gas pipeline infrastructure, and 3. a straight tie-back from a group of subsea wells to a third party platform for fluid processing/export.