Schlumberger

Case Study: Efficient, Accurate Gas Well Cleanup in Unmanned, Environmentally Sensitive Area

Remote monitoring and lighter, safer setup enables ADCO to make confident production decisions

Challenge: Test a remote gas well in an environmentally sensitive and operationally challenging field.

Solution: Rely on PhaseTester portable multiphase well testing equipment with Vx multiphase well testing technology.

Result: Efficiently cleaned up with representative flow rates and remote monitoring of basic sediment and water (BS&W), enabling early routing to production lines, saving hydrocarbons, and reducing emissions.

Alternative to conventional well testing in an environmentally sensitive area

The Abu Dhabi Company for Onshore Oil Operations (ADCO) operates a challenging field offshore UAE. Cluster A in the field consists of eight wells on a constructed island. The cluster, located in an environmentally sensitive area, is operated remotely and is normally unmanned. Therefore, ADCO desired an alternative to conventional well testing.

Performance and benefits unavailable from a conventional test separator

ADCO decided to qualify PhaseTester portable multiphase well testing equipment with Vx technology in a recently drilled gas well. The PhaseTester equipment was located upstream of a conventional test separator, and measurements by the two systems were compared.

To seamlessly integrate well test data with the reservoir simulation model, the phase behavior of the effluent was characterized based on the fluid properties provided by ADCO. The phase behavior data were then loaded into the fluid identification module of the PhaseTester system. During the well test, the PhaseTester equipment was operated in an environment with a very high gas volume fraction (ranging from 93% to 99% overall and from 95% to 98% for most of the flow period), where pressures ranged from 290 to 680 psi.

Gas well cleaned up successfully and tested accurately

During the well test, the PhaseTester equipment measured the decreasing water cut to 2%, clearly showing the final phase of well cleanup. The water cut measurement was confirmed by manual sampling from the PhaseTester sampling port, but the test separator was unable to provide a good water cut measurement or provide a representative sample.

Further, 90% of the PhaseTester measurements were within 4.5% of the test separator data for both liquid and gas rates. ADCO expressed a higher level of confidence in the accuracy of the PhaseTester measurements made with Vx technology than in the conventional test separator measurements.

Numerous other ADCO objectives were met, and additional benefits were realized compared with conventional well testing:

  • Installation and well testing operation safety were improved.
  • Test lines were eliminated.
  • Well testing was quicker and more efficient.
  • Well test data were transmitted in real time from the PhaseTester system to the ADCO SCADA system.
  • Accurate BS&W monitoring allowed the well to be switched to production with confidence that it had been cleaned. Early routing to the production line saved hydrocarbons and reduced emissions.

This test was part of a wider campaign to evaluate Vx technology and its applications. This has led ADCO to deploy Vx technology for mobile testing activities, including semipermanent applications to complement existing permanent testing facilities and for permanent installations where ADCO operates fixed meters for routine testing operations.

More than 800 well tests have been performed in Northeast Bab field alone, and a recent separator refurbishment campaign used PhaseTester measurements as reference to calibrate the upgraded test separators.


Download: Efficient, Accurate Gas Well Cleanup in Unmanned, Environmentally Sensitive Area (0.23 MB PDF)

Related services and products

 
 
Request More Information

Valid, Reliable Multiphase
Well Test Measurements

PhaseTester measurementsPhaseTester measurements
PrevNextZoom1 of 2
“Even in this challenging environment, the PhaseTester system made accurate, repeatable measurements with little or no stabilization time, so as many as three wells could be tested per day.”
Ibrahim Al Hammadi
Technical Support Manager
Northeast Bab Asset, ADCO