Real Results

Performance By The Numbers

HEL™ MWD System and Microflux® MPD Control System

Stand Up to Ultra-High LCM Concentrations in a North Sea HPHT Well

Objectives

  • Deliver full-performance drilling data and pressure control while pumping high concentrations of lost circulation material (LCM) to safely reach total depth (TD) in a high-pressure, high-temperature (HPHT) well drilling in the North Sea.

Our Approach

  • Weatherford worked in conjunction with a major operator to test the proof of concept for measurement-while-drilling (MWD) systems operating in ultra-high LCM concentrations. The operator had concerns regarding potential lost-circulation zones in an upcoming HPHT offshore well.
  • Weatherford MWD experts tested system performance in an onshore flow loop, where LCM pills were mixed at up to 147 lbs/bbl (420 kg/m3), or three times greater than industry standards. These LCM pills were successfully pumped through the hostile environment logging ( HEL) measurement-while-drilling (MWD) system. The HEL tools maintained full communications before, during and after the LCM pills were pumped through the toolstring. This gave the customer the confidence to pump LCM through the MWD tools, if required.
  • After spudding the well, the operator relied on the Microflux control system to provide early kick and loss detection and manage wellbore pressure changes, and used the HEL system to relay critical drilling measurements under HPHT conditions. The OneSync® suite enabled automated or manual control of the closed-loop drilling equipment for quicker response to changing pressures.
  • As anticipated, the operator experienced severe fluid losses while drilling through a fractured formation. In an attempt to seal the fractures, the operator pumped an LCM pill at 112 lbs/bbl (320 kg/m3). Despite the volume of LCM pumped through the HEL tool, it provided full data transmission to surface.
  • As drilling progressed, the operator encountered more highly-fractured zones, and was forced to perform multiple cement squeezes on the fly. Cement slurries of 17.5 ppg (2.10 sg) were pumped through the HEL and MPD systems, enabling the operator to drill ahead.
  • The Weatherford team carried out the job without any quality, health, safety, or environmental issues.

Value to Customer

  • The Weatherford MWD system identified the pressure at which losses were seen. Working with the MPD system, the bottom hole pressure was then maintained to allow further operations to address the losses.
  • The mud pulser and MPD system were able to stand up to the LCM and the cement slurries. The LCM and cement aligned to the MPD choke manifold and pumped through the HEL tool presented no problems for this equipment, which provided full functionality as expected; with no plugging through the valve, chokes, piping or downhole tools.
  • The capability to handle high-viscosity fluids through the pulser and MPD system provided the operator with flexibility to pump LCM and cement to treat the losses. Once losses were cured, the customer was able to drill ahead to TD.
  • The pumping of LCM through the MWD tools provided operational flexibility to reinforce the formation and expand the mud weight window from <0.01 to 0.03 sg.
  • Because the mud pulser is able to transmit through LCM, this material no longer needs to be bypassed through a circulation sub, which might otherwise open a single barrier pathway from the reservoir to the drill string.
  • The MPD system was able to identify losses in the early stages. While pumping the LCM or cement, the MPD system was able to maintain a constant bottomhole pressure to optimize results.

Learn More

Measurement While Drilling
 
Drilling Optimization Platform
 
Print Version
Details

Location

UK North Sea

Well Type

  • Vertical production well
  • HPHT

Total Depth

17,113 ft (5,216 m)

Hole Size

12-1/2 and 8-1/2 in.

Bottomhole Temperature

325°F (163°C)

Bottomhole Pressure

12,397 psi (85.47 MPa)

Products/Services

HEL™ MWD System and Microflux® MPD Control System Stand Up to Ultra-High LCM Concentrations in a North Sea HPHT Well

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