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.

Multiphase/wet gas flow meters used in deepwater subsea conditions are known tohave problems with scale from produced water and erosion from sand production. The objective of this RPSEA project is to evaluate the flow meter performancechanges produced by these meter altering mechanisms Multiphase/wet gas meter elements: Venturi, cone and wedge meters, werephysically tested and subjected to Computational Fluid Dynamics (CFD)simulations. The erosion testing was done with water-sand and air-sand on one size and onebeta ratio of each meter type. CFD simulations were used to extend the sizerange, the beta range and the fluid densities to cover the multiphase densityrange between air and water. Erosion results are presented that allows the user to estimate the possibilityor likelihood of wall penetration, the measurement error on a flow meter andthe effect of a flow meter on the erosion of a downstream bend. The scale deposition testing was done with brine of mostly sodium and calciumon one size and one beta ratio of each meter type. No attempt was made to useeither multiphase flow or realistic subsea conditions. Scale deposition is a highly complex and variable process that is difficult tomodel. For CFD to be able to estimate meter error it would have to predict thedistribution and thickness of scale in the meter. At present this is beyond thecapability of CFD. However, CFD simulations were run to assess how meters areaffected by scales that are sensitive to fluid scouring, pressure distribution, particle accretion and thermal effects. These CFD-based methods are sufficiently realistic to provide an insight intothe effects of scale. They are used to compare different meter designs andhence identify design features that may be desirable if scale formation is aconcern. 1. Introduction This RPSEA 07121–1301 [Ref. 1] project addresses gaps in the deployment and useof multiphase and wet gas meter technology in deepwater production systems. Inparticular the objective of this task is to understand the ways in whichproduction fluids affect subsea meters and thereby affect their meterresponses. It is known from field operations that meters can become fouled internally bydeposits of scale, or altered by erosion. At present these effects are not wellunderstood and the objective is to estimate their magnitude. Flow tests and computational fluid dynamic (CFD) analyses have been performedto evaluate the effects of alteration on Venturi, cone and wedge meters, byscale deposition and by sand erosion. The results are interpreted to give aclearer understanding of these meter alternation effects on subsea multi-phasemeter response.

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Multiphase metering flow meters (MPFM) are being accepted more and more in oil and gas developments, replacing test separators, particularly on fields with large well networks. This is the case with Steam Assisted Gravity Drainage (SAGD) oil sands developments requiring large capital investment that need accurate production and reservoir data and have difficult processing techniques. This data includes:Real time measurement: good reservoir and steam chamber monitoring and steam injection versus oil production surveys.Cost reduction: steam oil ratio (SOR) optimisation, due to the economic and environmental cost of steam.Asset integrity: mitigation of the risk of steam breakthrough in oil producer wells. The flow meters have to be sized for either viscous liquids (water in oil emulsions) or less viscous, but very hot liquids (oil in water emulsions) and to differentiate between gas and steam, or be able to meter the gas and assess the steam loading. In SAGD developments the water content determination is essential and the meters have to include qualified systems for both high temperature and high water cut measurements. This paper outlines the business needs for MPFMs in SAGD and discusses the current difficulties with qualification, test loops, field trials and eventually, the perceived operational issues. The challenges facing multiphase metering in SAGD developments are as difficult as the industry faced when applying classical multiphase metering techniques several years ago. In order that these challenges are overcome it will be necessary for vendors and operators to develop and test the new technologies jointly. This will require that vendors dedicate sufficient effort in MPFM R&D and that operators participate in these developments, in JIP's and host field trials. Introduction Reservoir monitoring and modelling improves reservoir knowledge, simulation, reservoir optimisation, prediction of breakthrough times & well performance for different operating scenarios. Reservoir models and predictions are based in part on surface metering data. The reliability and uncertainty of this data defines the sensitivity of any reservoir model. Reservoir monitoring enables competent operating strategies to be set and is used to compile the year end reserves. Monitoring of well performance and production can provide continuous information on well behaviour throughout the well life. SAGD production will require:Initial steam injection rate (circulating - i.e. steam chamber creation and oil heating)Ramp up (with gas lift injection),Steam liftGas lift\Blow down,Break through Good reservoir monitoring can optimise the well spacing, and well length and contribute to the system learning curve for future developments. In addition to reservoir management, metering must be compliant with the required regulatory reporting needs.

fax 01-972-952-9435. AbstractMultiphase metering flow meters (MPFM) are being accepted more and more in oil and gas developments, replacing test separators, particularly on fields with large well networks. This is the case with Steam Assisted Gravity Drainage (SAGD) oil sands developments requiring large capital investment that need accurate production and reservoir data and have difficult processing techniques. This data includes: 1. Real time measurement: good reservoir and steam chamber monitoring and steam injection versus oil production surveys.2. Cost reduction: steam oil ratio (SOR) optimisation, due to the economic and environmental cost of steam.3. Asset integrity: mitigation of the risk of steam breakthrough in oil producer wells.