While striving for operational efficiencies in downhole drilling is not new, virtually nobody would have speculated that technology would drive increased time/cost savings of up to $1 million or more per well directly from the common mud pit.
The technological innovation is not the rig or drillpipe. Instead, it is a lubricant, specifically a drilling mud additive that essentially breaks the rules for what lubricants can do. Not simply a fluid treatment for the mud to assist borehole drilling, XPL+ (Xtreme Pressure Lubricant) overcomes the major drilling nemesis—friction.
Fifty times more powerful
R&D at ProOne Inc. used some scientifically accepted facts about molecules and electrical charges to create a new lubrication formulation. Since other lubricants are repelled by extreme heat and pressure, the company’s engineers built a positively charged molecular structure that is attracted to extremes and bonds with metal under those conditions.
That unique bonding means that XPL+ provides film strength 50 times that of water-based mud that does not include the formulation. For example, on a bench cross axis friction test, the bearing was severely damaged at 4,000 psi compared to the bearing tested in water-based mud using XPL+ and resulting in only minor damage at 200,000 psi.
The bio-stable drilling fluid test method involved the Baroid lubricity meter and a 1.0 water coefficient of friction. With the coefficient of friction recorded at 26 C (78 F), results were an 85% decrease:
Ultra Carb System Initial
4% ProOne 0.062
With the coefficient recorded at 93 C (200 F), results were a 94% decrease:
Ultra Carb System Initial
4% ProOne 0.024
Solving array of drilling challenges
With mud integral to the entire downhole drilling system, R&D immediately focused on what a major friction-reducer could accomplish throughout the continuum from spud to total depth (TD). By providing much greater lubricity, friction is reduced overall by 70%, and torque and drag, always key drilling issues, are reduced by 20% to 50% while maintaining the critical weight on bit (WOB). With XPL+ being water-based, this drilling fluid can notably increase the boiling point of water-based lubricants. That provides the better WOB without wearing out mud motors and drillbits too quickly.
Being water-based plays another important role. Because this lubricant emulsifies in every water-based drilling mud and remains emulsified longer than other mud additives, it substantially reduces another drilling adversary: corrosion. Creating a layer of lubricant molecules that cannot be penetrated, it protects all metals, including critical moving parts within drilling equipment.
At more than 700 drillsites throughout North America, operators have used ProOne’s lubricant. On a Texas well, for example, highlights included a 40% torque reduction and increased WOB from 25,000 lb to 32,000 lb. This took two hours off a company record through decreased drag and increased sliding, with the drop in torque and an accompanying increase in the ROP. On another Texas well torque was reduced by 50% (maxed out from 9,144 m/lb to 4,572 m/lb [30,000 ft/lb to 15,000 ft/lb]), ROP increased 28% (12.5 m/hr to 17.5 m/hr [41 ft/hr to 57.5 ft/hr]) and WOB was 25,000 lb.
Across the drilling solution spectrum on a field-proven basis, this lubricant also eliminates excessive trips, facilitates easier steering, allows faster running of casing, drills curve in 50% of the time previously required and reduces hook load. Additionally, it helps free stuck pipe and works more effectively with long horizontals and deviated, spiraled or chopped holes. Other prominent time/cost savings include extending the lives of drillbits, mud pumps and mud motors as well as preventing the top drive from overheating and saving on drillstring repair.
Following the lubricant’s successful implementation in U.S. and Canadian drilling operations, extending its usage into coiled tubing (CT) applications became the next logical step. Incorporating the XPL+ technology, CoilPro provides the same key attributes of bonding to metal and applying film strength 50 times better than previously available.
Through pipe-on-pipe extreme friction reduction and rheological stability, the CT application improves drilling out all the bridge plugs. Operators familiar with XPL+ see the similarities shared by CoilPro along with its unique attributes. For example, CoilPro is water-dispersible, increases WOB, withstands heat extremes (more than 316 C [600 F]) and delivers exceptionally high film strength.
In addition to drilling more quickly through bridge plugs, CoilPro lubricates the interface between CT and casing. Standard usage is 3.8 l (1 gal) for every 3,785 l (1,000 gal) and, on deviated wells, 7.6 l (2 gal) for every 3,785 l.
In a case study, a Denver-based energy company had experienced problems with bridge plugs before using CoilPro to lubricate pipe-to-pipe interface. According to the company, it normally could not avoid leaving one to four bridge plugs in the lateral because they could not be milled out by the CT unit. For example, in early 2014 a badly deviated well prevented the company from drilling out the last four bridge plugs.
After the introduction of CoilPro to its drilling operations and on all subsequent wells, all plugs in all wells have been milled. Completion specialists have commented that it reduces milling time, the fluid’s performance exceeds other fluids or methods and, according to the production engineer, it has had a major impact on the bottom line.
Another energy company strategically located in major shale plays also decided to use the product in its CT operations and has concluded that price/performance is excellent. A completion specialist said, “In years of coiled tubing experience, I haven’t seen anything work as well for a pipe-to-pipe lubricant.”
Both XPL+ and CoilPro are “green” technologies, readily and ultimately biodegradable while having no toxic effects on marine life. On a specific biodegradation test, ProOne was already 60% degraded by the 16th day and by the 31st day had degraded by 83% on its way to final biodegradation.
Field-proven savings spud to TD
In actual usage on every drillsite from both a time and cost savings perspective, ProOne offers operators a field-proven way to drill and complete wells cost-effectively. And it all originated from R&D that determined a positively charged molecular structure with a strong ionic charge could provide extraordinary film strength and extreme downhole pressure protection.
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