A Semisubmersible type Drilling, Early Production and Testing System with 100,000 bbl Storage for Deepwater

Abstract

Abstract Deepwater petroleum development is increasing throughout the world. Complete evaluation of deepwater oil fields prior to development is extremely important but difficult due to harsh conditions and deepwater. Extended well testing and early production of a field will allow complete evaluation, reducing risk prior to long term commitments. Conceptual design andstudies for a semisubmersible type deepwater drilling, early production and testing system with 100,000 bbl storage (DEPTS) that will allow this have been completed. Needs analysis were performed and several potential concepts compared. Sizing and costing of the semisubmersible unit, mooring, and riser systems as well as selection of the drilling, production, and storage units were carried out. The unique aspect of the system is that the combination of drilling, production facilities, and storage on the same vessel will a How the system to be applied across the early phases of offshore oil field development from drilling to early production. With storage integrated into the vessel, oil production can continue in the most extreme conditions. The system's intended operational area will be the deepwater fields of Asia and Oceania. Studies have been carried out showing the technical and economic feasibility of the system in deepwater up to 2,000 m. Introduction The relentless trend of hydrocarbon exploration and development to deeper waters shows no sign of abating in the near future. Developments in 300m water depth are common, with the current deepest development being at 1027 m in the Campus Basin. Deepwater in the 2,000 m range is being explored, with the immediate question being which technologies are most appropriate for which fields. The large amounts of capital required for deepwater exploitation can lead to increased risk for the operators, necessitating measures to decrease risk, decrease overall development cost, or both. The use of extended well tests (EWT) or easy production systems (EPS) can be used for reducing risk, optimizing full development design, and improving cash flow. For the purposes of this study, the following definitions were used:EWT: An EWT is used only to obtain production data and reservoir characteristics.EPS: An EPS is used to obtain early cash flow and increase a project's economic viability. The usage of EWT or EPS can improve a project's overall viability in the following ways:The use of an EWT will reduce uncertainties about reservoir characteristic increasing the reliability of project economic forecasts.With better evaluation of reservoir production characteristics, the most appropriate exploitation concept may be developed and optimized, with possible corresponding decreases in total development cost and initial capital cost outlay.