Conoco to use MPFM at Kuparuk, Colville

AOGCC allows ConocoPhillips to use a new version of the metering technology for select purposes at the two North Slope units

Eric Lidji

For Petroleum News

The Alaska Oil and Gas Conservation Commission is allowing ConocoPhillips Alaska to use multiphase flow meters at the North Slope Kuparuk River and Colville River units.

The June 20 decision allows the company to use the metering system for well testing and production allocation, but not for custody transfer or fiscal allocation measurements.

ConocoPhillips plans to use a system that Multi Phase Meters AS of Norway developed as part of a multiyear joint venture that brought together ConocoPhillips, Shell, the Italian major Eni, the Norwegian companies Statoil and Hydro and the French major Total.

A multiyear testing program that began in Norway in October 2006 included a field test at the CD-1 pad at the Colville River unit in March and April 2010. ConocoPhillips installed the system upstream of a traditional separator used for measurements, and ran more than 80 tests on 16 different production wells at the unit during the trial run.

The field data at first suggested the meters under-read oil by 3.7 percent and water by 5.4 percent, and over-read gas by 7.3 percent. After some adjustments to how operators processed the readings, though, the meters under-read all liquids by 2.6 percent — 2.1 percent for oil and 3 percent for water — and under-read gas by 0.4 percent.

“The appearance of under-reporting in this instance could be the function of the duration of the field trial and the wells that were tested. Since the MPM will be used for well testing and allocation purposes a slight bias in one direction or the other would not be significant due to application of an allocation factor to adjust the test results to match the results obtained from the custody transfer meter,” AOGCC wrote in its ruling.

AOGCC also said it allowed ConocoPhillips to use the metering system in part because the Colville River unit tests results were comparable to results from other tests, showing that the system worked consistently under numerous well and fluid conditions.

The system also switches between multiphase metering and wet gas metering, allowing operators to measure “slugging” flow without having to partially separate the stream.

Use increasing on North Slope

Multiphase flow meters can measure all three phases without separation. The Multi Phase Meters AS system uses radio frequencies and other technologies to create a three-dimensional image of flow through multiple planes that measures the individual parts.

Accurate metering is important because it allows operators to monitor the changing profile of wells as they age, allocate production volumes among various royalty owners and perform other tasks dependant on measuring the fluids coming out of the ground.

Accurate measurements are increasingly important as new operators rent space at existing North Slope facilities. For instance, because Pioneer Natural Resources uses Kuparuk facilities to process the oil it produces from its nearby Oooguruk unit, the measuring systems for the two units are now intertwined. And as a major royalty owner, the State of Alaska is particularly interested in making sure that all measurements are accurate.

AOGCC previously allowed Pioneer to use Schlumberger Vx Multiphase Flow Meters for fiscal and production allocation at Oooguruk, and BP applied in January 2010 to use the same basic Schlumberger system at its offshore Liberty development.

The Oooguruk meters came under criticism in 2010 after a whistleblower complained about Pioneer and AOGCC operations, including the use of multiphase flow meters.

An independent investigation commissioned by AOGCC found no evidence of inaccuracy in the metering system, but said that AOGCC staff needed to develop clear criteria for overseeing the technology to make sure it worked as well as Pioneer claimed.