The Curious Case of the Deferred Capacity Profile – Solution to Forecasting Anomalies at Field D Off the Coast of Sarawak, Offshore Malaysia

Abstract Despite maintaining an exponential decline characteristic, the forecasting effort at oil field Field D was plagued by inconsistent EUR and deviation from real field performance. A solution to these forecasting anomalies was found in the concept of the Deferred Capacity profile, a very important but not fully understood phenomenon in production profiles. The aims of the paper are to discuss the importance of, the technique to generate, the solution to the field problem via, and the possible applications of, the Deferred Capacity profile. This paper is organised as follows: Introduction and discussion of the concept of the Deferred Capacity profile with a strong emphasis on its importance to preserve a production profile technical integrity in terms of volume and deliverability.Translating the concept into a spreadsheet-based profile generator.Validation of the spreadsheet-based profile generator with a conventional forecasting method capable of capturing subsurface dynamic behaviour.Implementation of the concept of the Deferred Capacity profile via the spreadsheet-based profile generator as a solution to the forecasting anomalies at Field D.Illustration of other possible applications of the Deferred Capacity profile concept. The discussion on the concept of the Deferred Capacity profile is meant to dispel the confusion with regards to which Capacity profile (production profile forecast without deferment) should be properly used to represent the subsurface potential of an Availability profile (taking into account production deferment). The generated Deferred Capacity profile could showcase the subsurface potential of the Availability profile at any given time while the associated Availability profile had the same volume as per the Original Capacity profile. One of the strengths of the spreadsheet-based profile generator to capture the concept of the Deferred Capacity profile is that it can handle a large amount of data without the cumbersomeness of manual calculations. It has shown great consistency when validated with a conventional forecasting method capable of capturing subsurface dynamic namely Petex MBAL. When implemented as a solution to the forecasting anomalies at Field D, the Deferred Capacity profile via the spreadsheet-based profile generator was able to preserve the EUR and reflect the real field performance. The concept of the Deferred Capacity profile is a very curious case since it does not exist on its own without the Availability profile yet is able to preserve the technical integrity of the latter in terms of volume and deliverability with respect to the Original Capacity profile. This is evidenced when the concept was used to solve the forecasting anomalies at Field D where it helped to ensure a consistent EUR between the forecasted Original Capacity profile and the Availability profile, as well as generating a Deferred Capacity profile that reflected the real field performance.