We present a methodology of converting standard reservoir models to maps of production potential for screening regions that are most favorable for well placement. A technique is developed to apply this method to the problem of field development where field production profile moves through successive phases of buildup, plateau, and decline. This results from successive drilling and commissioning of wells at a prescribed frequency (e.g., quarterly) until the total well ‘budget’ for the field is exhausted and eventual termination of wells as they reach prescribed abandonment criteria. This method, in general, results in an irregular well placement pattern, as it attempts to conform to both time-invariant reservoir properties (e.g., permeability field which may be nonuniform) and time-varying properties (e.g., pressure and saturation field). As such it is a well placement strategy governed purely by reservoir drainage objectives rather than infrastructure considerations which may favor a more regular and orderly well spacing pattern.

We illustrate this methodology for the case of a strong water-drive reservoir to be developed by horizontal wells under primary production. Specifically we examine how the field production profile and recovery factor is affected as the irregular well placement approach, driven by drainage objectives, is applied, compared to a fixed spacing approach. For both cases, an identical field footprint is simulated, that is, the same number of wells, type of wells, production programs, and abandonment criteria are applied; also both follow the ‘floor to ceilling’ well placement strategy in the reservoir which field experience suggests is advisable for bottom water-drive reservoirs.

We observe a marked improvement in field recovery factor, as manifested by a higher and/or longer plateau, for the case of irregular well placement. The gain reveals the large impact that may result from the systematic use of automatic history-matching techniques and advanced drilling and measurement technologies, the two pillars for the implementation of the method described in this study.

This method also suggests that the same parametric group used to convert standard reservoir models to maps of production potential, can be used to convert while-drilling measurements to the expected production potential of the well as the well is being drilled. This method has been described in a separate study, but that study was limited to the problem of placing a well in a dedicated drainage area. The current study describes the methodology of sequential well placement across the entire reservoir, therefore complements and completes this prior work.

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