Floating Mud Plant HUB: A Game-Changer in Offshore Drilling Logistics
Authors: Gomez Ernesto S. , Osorio Hugo F. , Obi Ikenna , Musa Ismaeel 
Published: February 2020

Drilling offshore gas wells is a very challenging operation since it involves a high number of offshore rigs, mud losses into formation, well control and adverse weather conditions. All of which minimize the drilling efficiency on those wells with huge attendant cost, if no proper arrangement is put in place to mitigate these challenges.

In the current setting where we can sometimes see rapid increase in offshore drilling operation challenges such as coping with severe drilling fluid losses into formations, the main challenge is to support offshore rigs with drilling fluid in a timely and seamless manner. As on-shore mud plant keeps up with a very high operational demand, launched and successfully implemented a new floating mud facility ("HUB") to improve supply and deliver mud materials and fluids to offshore drilling rigs.

This floating mud and chemicals storage plant (HUB) spot successfully reduced transit times, minimized delays and nonproductive time previously experienced by the drilling rigs operating in offshore gas fields. These delays were due to late drilling fluid deliveries from the onshore mud plant and extended times to mix high-density fluids on the rigs. This innovative model guarantees significant savings in terms of saving mixing times, providing chemical storage capacity, consequently minimizing unnecessary rig site operations. There is also a significant reduction in environmental, health, safety, and risk exposure resulting in optimized shipping, distribution, back loading of drilling fluids, reduction in the utilization of supply vessels and rig resources, to support severe lost circulation or well control events.

The HUB floating plant provides a full array of scalable fluids, mixing equipment and facilities to meet offshore operational requirements while eliminating the cost, extended lead-time, and specialized shipping. This plant encompasses a floating installation to mix and store drilling and completion fluids and chemicals. The HUB floating plant is equipped with twin mixing systems with the ability to mix and safely store more than 20,000 bbl of different fluid sets. It was recently utilized to mix high-density MICROMAX (manganese tetroxide) based completion fluid with excellent performance, despite the complexity of mixing over 2,500 metric tons (super-sacks), and still was able to handle different fluids seamlessly. This HUB is anchored within equal distance to the three largest gas fields. The reduction in delivery time is estimated to be 90% in both normal and emergency operations. Weighting materials and mud chemical storage capacity provides an additional platform to minimize rig deck utilization and drilling mud mixing construction capabilities, minimizing the huge coping pressure on the alternative onshore mud plant operations.

Over the last 3 years of being in operation, the HUB floating plant has mixed more than 916,000 bbl of heavy mud and completion fluid, received over 19,000 bbl for storage, and stored up to 400,000 ft3 of barite, with more than 600,000 workhours, without any near misses, incidents, or accidents.