By Maggie Cox, editorial coordinator
Simulation software is taking the steadfast methods of well control future forward. The industry is seeing a trend in demand by customers using well control services to plan new rig sites, reduce incidents and confront challenges.
“(Technology) makes (well control) a lot faster,” Dan Eby, vice president and engineering manager of Cudd Well Control, said. “There are a lot of wells that we work on that don’t actually blow out. The customer will call you and say, ‘I have a kick in my well; I need to kill it,’ and they will call us ahead of time. A lot of our work is going out there and helping the customer keep his well from blowing out.”
Implementing innovations from an “engineer’s perspective” provides a new approach to well control.
“Engineers think like engineers, and they want more engineered solutions to their well control problems, just like all their other drilling problems,” Mr Eby said.
By using simulation software, companies like Cudd, Wild Well Control and Boots & Coots can run multiple scenarios to determine the best ways to prevent well control incidents.
“By doing all of the pre-planning and doing the risk analysis and all the studies of risk, hopefully we are minimizing the big events,” Bill Mahler, executive vice president and manager of Wild Well Control, said. “We do a lot more pre-engineering work than what has ever been done before.”
Well control companies are also using well modeling and site reviews to minimize the risks that customers face when drilling their wells.
Mr Mahler commented that the perception of well control companies as being very expensive sometimes keeps operators from calling for help when a well control incident begins. Instead, they will try to resolve the issue without the benefits of well control engineering.
“If the conventional methods of well control do not work, you need to get outside help. We take phone calls from people saying, ‘We’ve been fighting this kick for four or five days,’ and we just want to say, ‘Why?’ ” Mr Mahler said.
Simulation software also aids in the placing of new wells by helping clients understand the external impact of their well, if it blows out. To prevent disaster, well control companies meet with community members even before the well is drilled to review safety precautions.
“Many oil companies are doing kick simulations or writing blowout contingency plans,” Mr Eby said. “We can do gas-dispersion modeling, which helps in knowing if you would have to move families, etc. … We work with the community and emergency services to discuss the new rig and preparation sessions.”
While preventive measures are being encouraged in well control, simulation software can also help address some of the challenges that drillers are facing.
With the market down, the need to tap mature fields is an ongoing issue. The question concerning old wells is, “What are the well’s pressure limits?” said Don Shackelford, senior well control engineer emeritus of Boots & Coots.
“Older tubulars in a well must be de-rated from new conditions, but the questions is, how much?” he said. “If production strings have parted, then fishing operations can be difficult because of the nature of the part, which is generally ragged in nature.”
Especially in deepwater drilling, well construction concerns are critical. The change in pressure gradient from seawater to the mudline versus a higher gradient from the mudline to a zone, which contains pore pressure, results in additional casing strings and larger initial wellbore diameters, Mr Shackelford explained.
“The primary problem for deepwater conventional well control following a formation influx is the ability to circulate without breaking down the open hole somewhere,” Mr Shackelford said.
According to Mr Mahler, barriers are also being seen in drilling on the onshore shale plays.
“We have seen an increase in the number of well control incidents during these frac operations as they are becoming more complex,” he said. “Operators and frac companies are experiencing more equipment failures in the pump lines and frac heads due to lack of proper maintenance and inspection between these extended frac operations. The large multi-stage frac (jobs) being performed currently, at the high pressures and with abrasive materials, takes its toll on the equipment’s integrity.”
Another technique affecting well control is managed pressure drilling (MPD). While MPD has allowed operators to extend casing points, the approach can lead to a kick tolerance near zero, Mr Shackelford commented.
“Unfortunately, the execution of these types of jobs almost always results in stuck drill pipe and BHAs. Following a successful well control operation, there is usually a sidetrack or a fishing job,” he said.
Some of the tasks in which simulator software can be applied are:
• Modeling of ECD & ESD.
• Modeling of thermal effects.
• Underbalanced and managed pressure drilling.
• Kick tolerance calculations.
• Surge & swab calculations.
• Design of well control equipment.
• Sensitivity studies.
• Evaluation of well design.
• Risk evaluations.
Trends in the US onshore industry, such as running multiple wells 20-40 ft apart on one pad, also make pre-planning well control a must.
“We know if there’s an incident involving one of these wells and it ignites, there’s really no protection for the other wells in place,” Mr Mahler said.
An emerging theme among well control clients is requesting a well control specialist on site to oversee the drilling of their new well, according to Mr Mahler.
“I think going forward, one of the risk management issues that we’ll see, depending on the areas they are drilling in, is that the operators are going to request a well control specialist be on location when they are drilling into formations to monitor strictly the well control issues in the ongoing drilling operation.”
Looking ahead, well control experts are envisioning improvements in data telemetry and “smart well” systems. They are expecting more demands from their customers in pre-planning well simulation and a physical presence of well control experts when drilling new rigs.
“Probably one of the biggest things is just trying to understand the new drilling technology,” Mr Mahler said. “Trying to get the industry to understand that the training of these people is critical to the future.”