Implementing Intelligent Well Completion in Brown Field Development

Abstract

Intelligent Well Completions (IWC) is an emerging technology, which allows operators to optimise reservoir management and field facilities performance. The implementation of this technology has generally been restricted to new field development due to the perceived complexity of integrating high-end IWC (combined monitoring and flow control) into current Subsea Production System (SPS) designs. However, intelligent completions can be applied to mature fields where reservoir performance and value added by IWC are well understood. The BP Machar well application is a typical example. One of the challenges facing the project team was the integration of the IWC control system within the constraints of the existing SPS. Minimum modification to the existing hardware and control system equipment was a requirement. A system approach, similar to the forthcoming ISO standard for integration of IWC into Subsea Production Systems, was used to ensure robustness of the design and testing concepts. Introduction The Eastern Trough Area Project (ETAP) comprises the integrated development of seven oil and gas fields. The fields lie in the vicinity of the Eastern Trough in the UK Central North Sea 150 miles east of Aberdeen in water depths of around 85–90m. Marnock, Heron, Egret &Skua are high pressure / high temperature developments containing gas, condensate and oil. Mungo and Monan are lower pressure diapir related fields with separate oil and gas legs, and Machar is another diapir field containing oil. Reservoir exploitation involves subsea facilities at Heron, Egret, Skua, Monan and Machar. Mungo is produced via a normally unattended installation. All fields are produced to the ETAP Central Processing Facility (CPF). This is located above the Marnock reservoir where fluids are processed prior to being exported to the Central Area Transportation System and the Forties Pipeline System. Figure 1 illustrates ETAP field layout. Machar Field Subsea Development Overview Machar is a subsea development some 35km away from the ETAP Central Processing Facility and consists of the following prime components: Subsea facilities Production manifold Water flood manifold 7 production wells 2 water injection wells 16" Multiphase production pipeline Subsea multiphase flow meter 12" Water injection pipeline Waterflood umbilical supplying power, communications and chemicals Production umbilical supplying power, communications and chemicals Subsea pigging facilities Subsea Production Control System Infrastructure. The SPS in BP Machar field is a multiplexed electro-hydraulic system. The facilities are controlled using a Kvaerner Oilfield Products (KOP) system that includes a Master Control Station (MCS) which operates multiplexed master / slave communications to the subsea wells. The MCS also provides a link to the platform Control Monitoring &Shutdown System (CMSS) through which, ETAP platform operators normally control subsea equipment. Each well has a dedicated Subsea Control Module (SCM) that controls and monitors the various tree functions. Inside the SCM is a Subsea Electronics Module (SEM), which provides outputs for the electro-hydraulic valves, and inputs from tree sensors. In BP Machar, 4th Generation type SEMs are used, hence the entire field uses KOP's proprietary 4th Generation protocol over the communications network running at 1200 baud. Subsea facilities Production manifold Water flood manifold 7 production wells 2 water injection wells 16" Multiphase production pipeline Subsea multiphase flow meter 12" Water injection pipeline Waterflood umbilical supplying power, communications and chemicals Production umbilical supplying power, communications and chemicals Subsea pigging facilities Subsea Production Control System Infrastructure. The SPS in BP Machar field is a multiplexed electro-hydraulic system. The facilities are controlled using a Kvaerner Oilfield Products (KOP) system that includes a Master Control Station (MCS) which operates multiplexed master / slave communications to the subsea wells. The MCS also provides a link to the platform Control Monitoring &Shutdown System (CMSS) through which, ETAP platform operators normally control subsea equipment. Each well has a dedicated Subsea Control Module (SCM) that controls and monitors the various tree functions. Inside the SCM is a Subsea Electronics Module (SEM), which provides outputs for the electro-hydraulic valves, and inputs from tree sensors. In BP Machar, 4th Generation type SEMs are used, hence the entire field uses KOP's proprietary 4th Generation protocol over the communications network running at 1200 baud.