A Cost Effective Methodology for Production Metering and Allocation Using Real-Time Virtual Metering in a Mature Offshore Oilfield- A Case Study of the Greater Angostura Field

Abstract

Abstract The objective of this paper is to demonstrate how the use of production modeling tools coupled with field pressure/temperature (P/T) data acquisition systems and Visual Basics (VBA) programming, was used as a means to improve production allocation and surveillance on a real time basis in the Greater Angostura Field. An integrated production model was built to represent the production performance of the Angostura field. The model was calibrated to accurately represent pressure, temperature and multiphase flow behavior of each well and the production networks. In order to achieve real time monitoring capabilities, a VBA program was developed to extract specific inputs from the field's data acquisition system and automatically load them into the model to perform user defined calculations continuously. The model outputs include the individual flowrates for all the wells in the field, while honoring mass balance and P/T drops across the production system. As a result from using this approach, more accurate real time production rates at the well level can be obtained. Production allocation was also improved reducing its error down to less than 10% for all three streams of production. This is crucial for effective reservoir management, simulation, and infill drilling/intervention studies. Finally, this methodology has also allowed undertaking various production optimization efforts which have resulted in above-target production. This paper shows a practical approach to obtain accurate real-time well production rates without the need of purchasing costly flowmeters for each well. It also demonstrates how virtual metering can be used to identify production optimization opportunities and/or issues in the production system more readily.