The Agbami field is one of the largest producing deep-water assets in Nigeria. It was discovered in 1998 and put on stream in 2008 with the field development staggered into three phases. Adopting a phased approach has eased the burden of project management and allowed the Asset team incorporate the key learnings of each phase into the subsequent phases while reducing uncertainty and improving decision making to derive maximum value from the asset. With the third phase of the field development approaching its later stages, it became necessary for the Asset team to take a second look at the wealth of data that had been gathered in the 7 years of production and re-evaluate the subsurface understanding with a view to identifying by-passed or un-swept oil that could potentially increase recovery from the reservoirs. Uncertainties are inherent in every project and the Agbami project is no exception being a major capital project with its fair share of uncertainties. This paper focuses on how the Asset team tackled the challenge of generating a meaningful and reliable production forecast for the infill drilling opportunities to drive decision making while accommodating operational uncertainties, equipment delivery scheduling and subsurface uncertainties in the reference case as the Agbami Phase 3 project was still on-going as at the time of this work. This was done through the application of design of experiments to generate low, mid and high realizations of the reference case which was then carried forward into the incremental case. This paper discusses the process utilized in establishing a range for these uncertainties from historical data and how this was integrated (using experimental design) to generate probabilistic forecasts for the infill drilling opportunities to drive decisions that would maximize the value of the Agbami field for all stakeholders.

Time-lapse seismic survey also known as 4D seismic has established itself as a useful tool for reservoir monitoring and has gained wide acceptance within the industry. Technological advancements in the area of acquisition and processing have further strengthened the case for its application. The recent 4D seismic acquisition and interpretation in Agbami has proven to be an economically viable means of adding tremendous value to an oil field irrespective of the development stage it is in, and has been an excellent enabler for reservoir surveillance and resolution of subsurface uncertainties. Effective management of a field such as Agbami requires a surveillance method which can provide insight into spatial fluid movements with time, which the traditional surveillance methods are unable to provide. This type of insight is required to support sound reservoir management and field development decisions which Agbami 4D seismic provides. The information from the Agbami 4D monitor has shed more light around the fault network architecture within the field and has validated and in some cases changed some of the initial assumption around the sealing nature of these faults. Also, originally planned drilling locations and completion strategies have been modified based on the insight from the 4D seismic. The 4D seismic has also created value in the calibration of the reservoir simulation models and the location of bypassed oil within the field for future infill drilling. Forward modeling of expected seismic response based on proxy simulations helps to set realistic expectations of what can be seen in 4D seismic data. This paper discusses the acquisition, processing and interpretation of 4D seismic surveys in Agbami and how this information is being used to maximize the value in the field for the stakeholders.