Infill Development Well Planning in a Mature Supergiant Oil Field

Safar, Ahmad Ebraheem, Kuwait Oil Company, Kuwait

Production from the Greater Burgan oil field began in 1946. Initially, infill development wells were drilled on a one-kilometer, inverted, seven-spot pattern. Later, early vintage seis­mic data were used to position development wells, but the data were poor quality, and the wells were often mispositioned relative to faulting. Also, once the optimum locations for the field were identified, development wells were positioned without regard to well spacing, sur­face facility constraints, or reservoir off take.

Today, the challenges of well planning in the giant Greater Burgan field are considerable. Off take is constrained geographically by local gathering center limits. Unbalanced off take rates have caused non-uniform water encroachment. 3-D seismic data and recent flow sim­ulation models have revealed the complex reservoir architecture and fluid flow between reservoirs.

To select and rank new well locations a set of criteria are set to judge the quality of a well location. Then each potential location is assessed to determine its probability of satisfying those criteria. The process yields locations that utilize any spare GC capacities and maximize reserves per wellbore. This paper describes how the following factors influence the current process for determining infill locations in the Burgan reservoir.

•Integrating sub-surface potential and the facility capacities

•Developing several key indices to effectively analyze and evaluate the locations. Theseinclude MHPVI (Movable Hydrocarbon Pore volume index), rate of water rise (ft/year), exploitation index (ratio of off-take to remaining oil in place of the sector to that of the field).

•Identifying & evaluating uncertainties regarding the critical parameters in the well plan-ning process.