Rock science

Drilling has long led the industry when it comes to technology, leaving completions with a need to catch up. During the IADC's Completions Conference – the first one the International Drilling Contractors Association has organized devoted solely to the art of completions – speakers talked about the challenges that lie ahead in completing wells in increasingly challenging technical and economic conditions. Jennifer Pallanich reports.

We are drilling wells now that we can't complete,' said Kevin Lacy ), VP of drilling and completion in the Gulf of Mexico for BP, during the November event. 'It's a great challenge ahead.' Some of the wells are possible because of high-spec drilling equipment, he noted, but the completions equipment is not yet available. 'We're starting to see (conditions) in excess of 15,000psi.'

Other looming challenges include wells beyond 30,000ft, bottomhole pressures exceeding 20,000psi, temperatures over 250°F, hard-to-reach bottomhole locations, complex sand face completions and complex intervention requirements, Lacy said. 'Some of these completions are as close to rocket science as you can get.'

And some project budgets are reflecting the complexities of the completions. Lacy noted it's 'not abnormal' for completions to gobble up 40%-60% of well costs.

Some of those costs are going to cover personnel. 'People issues are out of control, absolutely out of control,' said Moe Plaisance, Diamond Offshore Drilling's VP for international operations. He said at one point, a customer requesting a bid on a rig with 165 beds wanted 200. 'You don't need 200 people to complete a well. These beds are more expensive than the beds in this Omni Hotel,' he said about the site where the conference was being held.

'Rigs are just starting to be built with completions in mind,' Lacy said.

Even so, said Paul King, rig managerperformance for Transocean's Discoverer Enterprise, 'A completion rig looks a lot like a drilling rig' with the addition of fluids capacity.

The Lower Tertiary – aka the Wilcox Trend and the Paleogene – in the Gulf of Mexico also complicates matters, said Vikram Rao, executive director for Research Triangle Energy Consortium. 'This is 25 million year old rock in an environment where we're used to 8 million year old rock,' he said.

Additionally, the industry's wellknown aversion to risk kicks in when determining how to deal with potential sanding problems. 'We are defaulting to the most expensive option, and this is because we don't want to take the risk,' Rao said. He said the lack of an effective test for determining sanding propensity is one driver for that 'default' choice. 'You've got a test, nobody believes it, so you put a safety factor on it... but it's the best we've got.'

In short, he said, the industry needs an effective sanding predictor test. Without one, uncertainty will continue to force conservative – read expensive – solutions. Further, it leaves the industry in the position of 'treating the symptom, not the cause' in that it uses 'brute force engineering' to prevent sand from damaging production, he said. The ideal test would directly test the cohesion of the grains, tensile stresses on a core sample, and indicate different saturations, Rao said. 'Without such a test, you will not mitigate risk.'

When it comes to tubing, extreme tensile loads are an issue, Doug Bolingbroke, Hess' Gulf of Mexico completions team leader, said. The simplest option is to 'make it bigger or make it stronger. If it's not strong enough, make it bigger,' he said. He noted, however, no matter how thick the pipe is, there will still be stress. When it comes to slickline, Bolingbroke questioned whether the industry really needs to use slickline at 30,000ft below the surface. 'We can get there. We can get there, just. But we can't do anything when we get there.'

Lee Hardin, completions team leader for the Gulf of Mexico deepwater E&P for Chevron, said the industry has some examples of working together to overcome challenges but needs more. 'A lot of informal sharing goes on in partnerships,' he said.

Don Jacobsen , SVP of operations for Noble Corporation, said uncertainties remain in completions. Sometimes, he added: 'We may know a lot about it but be challenged by what the properties are.' The uncertainties and challenges pile up to increase risk, which increases costs, he continued. 'We're frac packing everything,' Jacobsen said. 'Is that what we really need?'

With drilling and completions work eating up 40-60% of well costs, Lacy said, the industry is recognizing it needs more complex yet cost-effective completions technology. 'Completions engineers have historically felt like red-headed stepchildren.' They are finally coming into their own. OE

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