MPD helps to drill ‘undrillable,’ adds layer of safety
Managed pressure drilling (MPD) is an enabling technology for this industry to drill “undrillable” wells while providing an additional barrier and control, panelists agreed during the opening session of last week’s 2011 IADC/SPE Managed Pressure Drilling & Underbalanced Operations Conference & Exhibition in Denver, Colo.
Panelists were Will Pecue, president, Taylor Energy Company; Vincent Roes, well engineering team leader – international operations (East), Talisman Energy; Bob Blank, VP international operations Eastern Hemisphere, Diamond Offshore Drilling; and Dan Eby, senior well control engineer, Boots & Coots. The session was moderated by Mark Mitchell, VP drilling optimization services, Weatherford International.
Mr Pecue noted that reliability comes from a combination of three factors – people, process and equipment. While the industry has addressed the first two factors, he believes that the equipment factor has only been addressed “reactively.” Whether it’s an extra set of shear rams or spill containment systems, these pieces of equipment are about increasing industry’s capability once an event occurs.
“We have not done a single thing in implementing technology on the preventive side. This is it,” he said, referring to MPD. “And I truly can’t understand the reluctance from a lot of operators embracing this technology on a broader approach as a preventive means and a greater level of risk integrity to their operations.”
Mr Pecue added: “Five years from now, it is inconceivable to me that any newbuild rig, be it land or offshore, will not have managed pressure drilling built in as one of the key components.” Further, 10 years from now, he believes that MPD and its equipment will be just as a key and integral part of the rig as the top drive is now. “It wasn’t too long ago, 15, 20 years ago, that top drives were a novel accessory,” Mr Pecue said.
Talisman’s Mr Roes noted his company sees MPD primarily as an enabling technology that will allow them to drill the undrillable. “The operational efficiency improvements are really just a subsidiary effect,” he said.
Mr Roes is currently involved in an exploration program in Kurdistan where an offset well had taken a year and a half and cost more than $150 million to drill – and still failed to deliver the objectives. “We’re going to be deploying automated MPD on that project hopefully to get a more successful outcome,” he said.
Another project coming up later this year in Indonesia will use the Transocean GSF Explorer drillship, outfitted with MPD equipment. “The driver there is very serious lost-circulation problems,” Mr Roes said.
He also believes that MPD has value in preventing the escalation of downhole problems that can lead to HSE concerns. He recalled a project years ago for a previous employer where MPD was deployed to get the well down after two failed attempts. The pore pressure/frac gradient window had closed to a point where wells couldn’t be drilled conventionally anymore. On the first attempt to drill the well, a major lost-circulation event led to hole instability problems. Ultimately the well had to be suspended.
The team then came back with a revised well plan using automated MPD. “We basically opened up the pore pressure/frac gradient window by cutting back the mudweight and just holding the backpressure on connections. … Really it was a very routine job. We didn’t experience any losses, got the liner to TD and delivered the well without any drama. The point here is avoidance of those kinds of hole problems that could escalate in well control or other situations with HSE consequences is another enhancement to safety that we can expect from wider deployment of MPD.”
Addressing MPD from a drilling contractor’s perspective was Diamond’s Mr Blank, who said that he sees MPD as a good thing that allows more wells to be drilled safely. At the same time, however, drilling contractors do have myriad concerns that must be addressed before MPD can be deployed from a floating rig. “You know us drilling contractors. We don’t like change very much, but we do love a challenge. So the question is, OK, how are we going to do it?”
“First, the crew has to be knowledgeable and very, very comfortable with what they’re doing. Without that, we’re not even going to get started,” Mr Blank said. But there are also many considerations for the rig and equipment:
• Space out constraints and heave tolerance.
• Tension, OD and ID constraints.
• Hose and control line protection.
• MPD equipment safe handling.
• MPD equipment clearance with rig equipment.
• Tie-in to rig systems.
• Drillstring considerations.
When an audience member asked Mr Blank what drilling contractors should be doing to proactively put MPD on rigs, he responded that drilling contractors are anxious to give customers what they want. But he likened drilling contractors proactively putting MPD equipment on rigs to “Field of Dreams” – build it and they will come? “What I’ve seen on MPD systems, I haven’t seen two alike yet,” Mr Blank said, adding that he doesn’t believe drilling contractors can “proactively” put MPD systems on rigs at this point in the technology’s evolution.
The final panelist, Boots & Coots’ Mr Eby, said that the benefits of MPD in well control are well documented. “It’s all related to kick sizes. … The main benefit from MPD on the well control side is you have very, very small kicks. Whenever you limit the kick size, we maximize the chance for success for a kill. We also minimize any potential for wellbore damage,” he said.
However, in order to gain the main benefit of well control with MPD, the equipment can’t be online only when we’re making hole. “We don’t only take kicks when we’re actually making hole. We take lots of kicks when we’re running casing, when we’re logging, when we’re cementing, after cementing – all these other types of things,” Mr Eby said.
In deepwater applications of MPD, Mr Eby believes that equipment footprint could be a hurdle. He recalled one deepwater exploration well a couple of years ago that was drilled using a drillship built in Russia in the early ’80s. “Just because it’s deepwater doesn’t mean we’re going to have a big huge semi out there where we have lots and lots of room for this type of stuff.” He suggested that equipment audits could be a mitigation solution.
On the personnel side – where “deepwater personnel don’t know much about MPD, and MPD personnel don’t know much about deepwater” – Mr Eby said that training will be the biggest mitigation. Holding drills and kill wells on paper (KWOP) exercises would benefit both personnel at the rig site and at the office, he said.