The application of Multiphase Meters (MPM) over the past decade or so has, in the main, been in deployment of meters in small quantities (i.e. ones and twos) and there are few applications where MPM's have been deployed in bulk. Petrozuata in Venezuela is such an operation where 37 MPM's were deployed and have been in use for over 5 years.
This paper describes the facility and the operations where MPM's have been selected, tested and implemented. The paper also describes the difficulties experienced and the operational results from the extensive use of such measurement techniques.
Introduction
Petrozuata is a joint venture Strategic Association owned by ConocoPhillips (50.1 percent) and Petróleos de Venezuela, S.A. (PDVSA), the national oil company of Venezuela (49.9 percent). The project is a fully integrated crude oil processing and petroleum business, located in the state of Anzoátegui, Venezuela. It began commercial operations on April 12, 2001, however Extra Heavy Crude Oil (EHCO) began flowing in mid 1998. Petrozuata's primary function is to produce EHCO from the Zuata region of the Orinoco Oil Belt; transport it to the Jose industrial complex on the north coast of Venezuela; upgrade it into 19 to 26.5 degree API synthetic crude; and market it along with 14 degree API gas oil and associated by products e.g. LPG, sulfur and petroleum coke.
The Petrozuata "project" is now an operational oil producing business with over 5 years production experience. The Strategic Association has a 35-year operating life and will require the drilling of more than 750 wells with an estimated recovery of approximately 1.6 billion barrels of Extra Heavy Crude Oil (EHCO) during this period. This facility uses the ConocoPhillips' proprietary coking technology to upgrade heavy crude oil into lighter synthetic crude and has a nameplate capacity of 120,000 barrels per day (BOPD). At present, Petrozuata produces more than 125,000 BOPD of EHCO. The synthetic crude oil produced by Petrozuata is used as a feedstock for ConocoPhillips' Lake Charles, Louisiana, refinery and the Cardón refinery in Venezuela, operated by PDVSA.
Since 1997, Petrozuata has drilled more than 260 wells (at present there are 195 active producers) in an area of 56,000 acres of the Zuata region with the expectancy of drilling a further 490 wells over the next 30 years in order to drain the reservoir. Wells are clustered around 37 production pads as shown in Figure 1.
Conceptual engineering for the Petrozuata project was carried out in the early 1990's, and a substantial body of engineering was put forward for the use of multiphase technology for both pumping and measurement. Initial engineering required steam flood of the reservoir; however, this was later changed such that production is now based on the use of cold horizontal wells in unconsolidated sands with the extensive use of single and multi-laterals (1). Production is moved around the field via 11 off 2000 hp multi-phase pumps (MPP), with the EHCO diluted with naphtha. Within the field, the production is metered and allocated using 37 multi-phase meters (MPM), one located at each production pad as shown in Figure 2. The diluted crude is processed (degassed and dewatered) at a central processing facility, after which, it is fiscally metered and pumped to the upgrader via a 125 mile 36 inch pipeline.
