Moving Toward Intelligent Field Applications: MPFM for Production Rate Testing and Beyond
Authors: Al Yateem Karam S. , Al Amri Nami 
Published: March 2012

Prior to the broad implementation and utilization of Multiphase Flow Meters (MPFMs) in Saudi Arabian offshore oil fields, rigorous testing was performed utilizing in-series MPFM systems in conjunction with Saudi Aramco's testing fleet that are equipped with a conventional separator testing trap. Sets of data were collected simultaneously from different wells through different MPFMs, completed in different reservoirs, for about a year to compare and validate the results. The accuracy of the MPFM proved to be within engineering acceptable margin of error for all parameters and in most cases matches the conventional methods of testing results. Since then, offshore platforms are being retrofitted with a MPFM to be able to test all the wells on the platform by selectively switching them one at a time through a test line physically and remotely.

Since its pioneer implementation almost a decade ago, MPFM testing accuracy and the technology has improved considerably. The use of the MPFM has many advantages in the testing operations, especially during periods where the demand is high. Accurate and frequent well testing becomes decisive in times of maximum production rates since the results from well tests facilitate determining which wells are under significant decline and which have increasing water cut in a real time fashion especially for fields with large number of wells. The quick identification of these problems leads to taking immediate action to restore the wells' productivity toward maintaining optimal production rates. The MPFM offers real time well performance monitoring through the Supervisory Control and Data Acquisition System (SCADA) and has an added benefit of shorter test rate stabilization times. Additionally, the induction of the remotely operated selector switch in the units recently allowed full automation of the process of switching remotely different wells for well testing on a multi-well platform. It also minimizes human involvement and provides operational flexibility. In addition, it reduces the waiting time for wells' switching due to natural limitation factors, such as bad weather offshore.

This paper largely addresses the reliability and accuracy of MPFMs as compared to a conventional separator and to a portable MPFM as well as using electrical submersible pump (ESP) optimization application to identify what method gives more accurate testing. Further optimization of ESP well's performance with frequent testing is also accomplished, which in turn improves the sweep efficiency of the reservoir, accelerates the production of recoverable reserves and environmentally help improve pump run-life. The paper will also elaborate on the benefits attained from installing MPFM in mature offshore oil fields with a focus on special cases like the MPFM in-series testing, testing artificially lifted wells, smart well completions and newly completed wells. It will illustrate the benefits attained with focus upon special cases like the MPFM in-series testing, artificial lift wells, smart well completions and newly completed wells exhibiting an indirect support in achieving the production targets. Different principle and theory behind MPFMs will be highlighted with advantages along with a vision of the way forward. Further to the benefits of installing MPFM, the paper will also discuss lessons learned and improved guidelines imposed over wellhead sampling (WHS) benefiting from the success of the MPFM. These guidelines effectively minimize sampling in wells equipped with MPFMs.