Multiphase Pumps and Flow Meters - Status of Field Testing
Authors: Skiftesvik Per K. , Svaeren Jon Arve 
Published: October 2008

With the development and qualification of multiphase pumps and multiphase flow meters, two new tools have been made available to the oil and gas industry for enhanced production from existing installations or new field developments. This paper presents an overview of the major achievements gained from various test installations canted out the last years using equipment qualified by Framo Engineering AS.

The expedience from the extensive Field Verification Programmed as described shows that multiphase pumps and meters can operate in various and often harsh well environments providing significant well stream pressure boost or acceptable phase accuracy measurements of oil, water and gas.

INTRODUCTION

Multiphase pumps and flow meters are today commercially available, and as a consequence an increasing part of the oil industry has accepted the technology as of today to be mature enough for use in their oil and gas fields. This is a result of several development programmed carried out the last 5-8 years by various manufacturers which also have included extensive testing of the equipment in actual field environments.

This paper is meant to provide an overview and status of the major achievements gained from field testing of various multiphase pump concepts and multiphase flow meters developed by Framo Engineering AS. Major sponsors for the developments have been A/S Norske Shell, NAM, SIPM, Statoil, Mobil, Norsk Hydro Conoco, BP, Elf, Svenska Petroleum and the Official Governmental Royal Norwegian Council for Scientificand Industrial Research (KAPOF - Capitalisation of Offshore R&D).

Current plans for further ongoing development and qualification work are also presented.

FIELD APPLICATIONS AND POTENTIAL BENEFITS

Multiphase Pumping

Utilization of this tool may under the right circumstances provide considerable commercial benefit to the operatorsIncrease the reach of satellite fields to thereby utilize existing infrastructureIncrease the basic production rate for satellite developments or potentially increase the total recoverable reservesImprove production profiles maximum plateau and from deepwater developmentsBalance the wellhead performance from commingled multiwell or multitemplate completionsReduce the sensitivity to increase in water cut, i.e.maintain production rates at increased water cuts

Field scenarios likely to benefit from the utilization of multiphase pumps maybe classified as followsIncorporation in existing production facilities in order to enhance production rate and total recoveryNew developments of medium and small size marginal fields in developed areas as satellites by utilizing existing in-field gathering, processing and transport facilitiesNew developments in remote areas with no existing infrastructureDeepwater developments (in combination with floating production)

Pump Principle Selection

When specifying a multiphase pump for an actual application the first challenge is to accurately define the range for the most important functional requirements:Total volumetric flow rate at suction conditionsPump differential pressureGas Volume Fraction (GVF)Water cutEfficiency

Figure 1 shows a performance comparison of different multiphase pump principles for various combinations of total flow rate (at suction conditions), GVF and pressure.

Further it is essential to define operating parameters related to:

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