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This paper describes a dynamic reservoir modeling study and recommendations on the field implementation of intelligent well technology (IWT) on a mature North Sea field to quantify the benefit of using the technology for the redevelopment of the field. The study examines the impact of applying intelligent well technology to multiple production and injection wells to accelerate production, reduce well count, extend production plateau period and reduce well intervention. The field is located in the North Sea with characteristics similar to the Brent field. Major hydrocarbon accumulation exists in four horizons. The field is mature with over 10 years of historical production data from waterflood operations. The paper discusses issues relating to identification of the best application of IWT in the field and quantification of the potential gains from such application when compared to conventional completion systems. These include assessing the capability of the IWT to maximize oil production while managing water breakthrough and to commingle production from multiple sands while minimizing impact on reserves. The study highlights potential pre- and post- installation issues with regard to the recommended intelligent well systems. This includes challenges and issues related to integration with existing facilities, well installation, crew preparation, system reliability, etc. The paper also discusses post installation well controls and practical guidance on measuring the predicted benefits from using the IWT. The paper provides an overview of the application of intelligent well technology on a mature offshore field. The study estimated potential increase in oil recovery factor ranging from 0.48% to 6.1% of STOIIP over field life. Introduction The use of intelligent well technology in field development has been addressed by several authors. Oberkircher1et. al presented a review of different applications and integration of intelligent and multi-lateral well systems. The authors highlighted benefits and drawbacks and potential solutions of selected applications. Brnak2et. al. described the application of the technology in a CO2 enhanced oil recovery project in the SACROC unit of the Kelly-Snyder field. Based on the initial results from the projects, the authors indicated that significant reduction in CO2 production can be achieved while maintaining economic oil production. An application that integrates intelligent well system with multi-lateral technology in three horizontal subsea wells in the Gullfaks South Stratfjord field was discussed by Haugen3et. al. The implementation resulted in estimated reserve increase to 5.4 MM Sm3. The main attraction for using the technology was to provide required flexibility to control contribution from different branches of the multi-lateral wells. In a satellite offshore Malaysia field, Bogaert4et. al. described an integration of gas lift optimization with intelligent well system for real-time flow estimation and remote process control. This application resulted in about 10% production gains and 2% additional reserves. The main objective of this study is to identify the best application of intelligent well technology (IWT) in the field and quantify the potential gains from such application when compared to conventional completion systems. The conventional system considered is commingled production without zonal control. The study assesses the capability of the IWT to maximize oil production while managing water breakthrough and to commingle production from multiple sands while minimizing impact on reserves. The technical performances of these cases are compared using the same base reservoir simulation model. Multi-position downhole flow control valves were considered to determine the appropriate functionality required for the field. The results of the study will also be used as the basis of utilizing the IWT for the field re-development activities. The field is located in the North Sea with over 10 years of historical production data. The field was initially developed using the traditional plug and perforate concept.

1. Abstract Realistic modelling is essential for both the planning and the optimal operation of Oil and Gas Fields. Such a model for modern well or field development architecture requires coupling of the reservoir simulator with the well/surface facility network model when making choices as to the reservoir and production management strategies to be employed. Such close coupling is not, currently, readily available; particularly when the reservoir simulator, the well/surface facility simulator and, potentially, the optimiser programs are provided by different suppliers. We have had the opportunity to test a newly developed "link tool" to integrate the reservoir simulation model with a subsurface/surface network model, allowing (automatic) optimisation of the full network performance. The tool supplies the simulation results to the surface network simulator/optimiser, which in turn, reconfigures the intelligent well completion zones by use of Individual Control Valves (ICVs) and wellhead or manifold in order to maximise the total production against the well and facility constraints. The network targets are then returned to the reservoir simulator in a simple manner at each time step. The authors have used the S-Field over a number of years which proved to be a very suitable case study for illustration of the value of "Intelligent" Field development techniques. This paper discusses the automatic, optimal control of the S-Field's five intelligent production wells by application of a "link tool" (Supplier 1) to couple the reservoir simulator (Supplier 2) with a surface network modeller and optimiser (Supplier 3). N.B. The latter two suppliers are among the market leaders within their segments. 2. Introduction The integration of the reservoir simulator with the wellbore and surface facility models forms an essential part of the "intelligent" field concept. It allows accurate management of the reservoir(s) potential under specified well, facility or other constraints. The full value of such an integrated modelling workflow is only realised when a flow network optimisation capability that maximizes oil production (or other measures of value) is included in the software package. The optimiser works by making adjustments to the production strategy throughout the field life through its close coupling with the reservoir, wellbore and surface facility models. Many commercial software packages offer the capability to integrate subsurface and surface models. However, not only are there differences in the degree of coupling between the individual software programs, but these links usually place high demands in terms of computing power, network architecture and, frequently, manual intervention of the engineer. In this paper we will illustrate a successful application of a robust and efficient linking tool developed to couple a commercial reservoir simulator with a surface network simulator and Sequential Quadratic Programming (SQP) optimiser 1,2. The S-Field (a case study based on redevelopment of a real field with an Advanced or Intelligent Well development strategy) has been previously studied in-depth. It has been found to be a very useful case history to illustrate the potential advantages of implementing an Advanced Well development scheme 2,3. We have been able to show how the SQP optimiser can be used to increase the recovery compared to manual optimisation. This was achieved with a limited engineering manpower compared to the previous manual optimisation approach while the computer power requirements were less than that anticipated with other commercial optimisation software packages.