Subsea Development of Marginal Deepwater Fields

Abstract

Development of greenfield deep water oil and gas fields are generally known to be expensive, compared with conventional shallow water fields development. Having marginal fields in deep water only compounds the challenge to development. This presentation aims to discuss the challenges associated with developing marginal gas fields in deep water. It however centers primarily on the subsea portion of the development. Marginal gas fields are typically < 500 bcf, and are best developed when there is an opportunity to combine a number of such marginal fields for a clustered development. However, invariably, each field has different characteristics (volume, pressure, composition) and hence requires careful planning to ensure constant flow to production facilities. The presentation will thus elaborate on the use of software tools such as Maximus for phased field development planning to ensure base load gas production throughout the project lifetime. At FEED stage, the subsea facilities and topsides facilities are typically carried out by separate design contractors, involving an interface at the surface that needs to be managed well to ensure optimum overall system design for smooth economical operation. In the case of developments utilising FLNG the interface issues can become rather complicated when the subsea facilities design team at FEED stage has to interface with multiple FLNG FEED contractors participating in a design competition. The challenges centred round the subsea development include Field Layout planning, FPF interfaces, subsea CAPEX, Flow Assurance, Hardware limitations (qualification), Technology (applications of dual directional subsea wyes, and subsea pigging launcher/receivers). The presentation will also elaborate on the use of other software tools such as ArcGIS for pipeline route layout planning and optimisation, and Star-CCM Plus for sand erosion CFD (Computational Fluid Dynamics) modeling.