Premier Oil Reduces Total Pit-Cleaning Time by 90%, Slop Waste Generation by 56% Offshore UK | Schlumberger
Case Study
Location
United Kingdom, Europe, Offshore
Details

Challenge: Reduce personnel confined-space time, overall pit-cleaning time, and volume of wastewater created while cleaning the tanks of a semisubmersible rig in the UK sector of the North Sea

Solution: Deploy the ATC automatic tank-cleaning technology

Results: 

  • Decreased slop waste generated by 56%
  • Reduced confined-space entry time logged
  • Reduced total pit-cleaning time by 90%
Products Used

Premier Oil Reduces Total Pit-Cleaning Time by 90%, Slop Waste Generation by 56% Offshore UK

ATC automatic tank-cleaning technology improves efficiency while reducing personnel confined-space time, North Sea

Reduce HSE risk and time requirements for tank cleaning

For performing pit cleaning onboard the Ocean Valiant semisubmersible rig in the UK sector of the North Sea, Premier Oil has historically used traditional tank-cleaning methods, including high-pressure washers and vacuum units to clean the rig tanks between changing drilling fluids. This process is not only time consuming but also heavily relies on personnel confined-space time and generates large volumes of waste washwater, which then have to be properly disposed of at a significant expense.

Premier Oil Reduces Total Pit-Cleaning Time by 90%, Slop Waste Generation by 56% Offshore UK
Comparing the slug pit before (top) and after (bottom) cleaning demonstrates that the ATC technology delivered a brine-quality cleaning job.

Deploy automatic solution for tank cleaning

After consulting with Premier Oil about its objectives, M-I SWACO recommended using the ATC automatic tank-cleaning technology, which comprises a skid-mounted washwater recycling unit and programmable tank-cleaning machines (TCMs) that can be deployed on hard-to-reach areas. The technology requires only 7 m3 [44 bbl] of washwater, which is continuously cleaned and recycled throughout the cleaning process for reduced wastewater generation.

As a result, the technology delivers significant reductions in personnel confined-space time, overall pit-cleaning time, and the volume of wastewater and slop created compared with the traditional methods used in past pit-cleaning operations.

Significantly reduced slop waste and pit-cleaning time without compromising HSE quality

ATC technology was rigged up and cleaned six pits in 56 hours, representing a 90% reduction in cleaning time compared with previous operations using traditional tank-cleaning methods. Only one hour of confined-space time was necessary to place the TCMs in one of the tanks. A fixed volume of 7 m3 of washwater with 1% surfactant was used during the cleaning job. By deploying the ATC technology, Premier Oil achieved a 56% reduction in wastewater generation compared with the cleaning method previously used.

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ATC technology generated 56% less waste and reduced total pit-cleaning time by 90% while requiring less confined-space time by personnel.
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The TCMs can be programed to target hard-to-reach areas to break down and remove built-up solids in the tank bottoms.
Products Used

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