Publications

Significant oil production potential remains in many older fields that are not necessarily candidates for enhanced recovery (EOR) techniques. Frequently, the reservoirs are complex and the historical data limited. These characteristics may make detailed reservoir simulation difficult and time consuming to perform. Further, devoting limited reservoir engineering staff and resources to these fields may at first glance appear questionable when EOR candidates are available to study. Still, in most cases, future performance of these fields can be improved through an appropriate evaluation of the available geology, reservoir, and production history information.The Petani field, with its numerous ctacked reservoir sands and commingled production history, represents one such field. This paper describes the reservoir study approach to this field, involving classical andlow technology techniques, leading to the development of short-term operating recommendations and a longer term depletion plan. The approach is quicker than a major reservoir simulation study, allows more specific and immediate recommendations to the production engineers, and can be used by engineers withouthigh technology tools.Key aspects of the study involved use of methods to visualize reservoir characteristics and performance history information. These types of methods enhance the engineers ability to generate ideas about the field, which are often much more valuable than the specific calculations and modeling performed in a given study. In addition, such ideas may carry over and impact the companys operations in other areas.