Time Lapse Seismic Survey: Adding Value in the Agbami Field

Abstract

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.