Cost-Effective Production Metering and Allocation in a Mature Offshore Oil Field

Abstract

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 180887, “A Cost-Effective Methodology for Production Metering and Allocation Using Real-Time Virtual Metering in a Mature Offshore Oil Field: A Case Study of the Greater Angostura Field,” by Italo Raffaele Acuna, BHP Billiton, prepared for the 2016 SPE Trinidad and Tobago Section Energy Resources Conference, Port of Spain, Trinidad and Tobago, 13–15 June. The paper has not been peer reviewed. This paper describes how the use of production-modeling tools, coupled with field pressure/temperature-data-acquisition systems and programming software, served as a means to improve production allocation and surveillance on a real-time basis in the Greater Angostura Field. The complete paper discusses a practical approach to obtain accurate real-time well-production rates without the need for purchasing costly flowmeters for each well. It also demonstrates how virtual metering can be used to identify production-optimization opportunities in the production system more readily. Introduction The Greater Angostura Field is located 25 miles offshore Trinidad and Tobago. The field was developed in three phases: Phase 1, which includes the Kairi, Canteen, and Horsts fields; Phase 2, which includes the Aripo gas development; and Phase 3, which was scheduled to have been completed by the second half of 2016. At the time this paper was written, the Angostura development consisted of 21 producers and seven gas injectors. The facilities and gathering system included one manned central-processing platform (CPP), four unmanned well- protector platforms (WPPs), and one gas-export platform (GEP). All wells have dry production trees and are distributed as follows: Canteen 1 (C1) WPP: five producers and two injectors Kairi 1 (K1) WPP: three producers and two injectors Kairi 2 (K2) WPP: nine producers and three injectors Aripo (A) WPP: three producers The production from the wells in each WPP is commingled in each platform’s header and routed as follows: Canteen 1 (C1) WPP: one subsea production flowline to the low-pressure gathering system Kairi (K1) WPP: two subsea production flowlines to either the low-pressure or the high-pressure gathering system Kairi (K2) WPP: two bridge-connected flowlines to either low- or high-pressure gathering system Aripo (A) WPP: one subsea production flowline to GEP The oil produced from C1, K1, and K2 is processed on the CPP and pumped to shore. The gas produced from these three WPPs is distributed to export gas. The production of the Aripo WPP is sent directly to the GEP for sales.