I was invited down to Brownsville, Texas this week to meet with senior executives from Helix Energy Solutions Group (ESG) for an overview of their company’s well intervention operations and a rare opportunity to tour the Q4000 semisubmersible which was in drydock at Keppel AMFELS shipyard.
Oilfield diving legend Owen Kratz, now Chairman and CEO of Helix ESG, describes subsea well intervention as “the ability to safely enter a well with well control for the purpose of doing a number of tasks other than drilling.” A subsea production well, after its initial completion, may require a number of additional interventions over its lifespan for a number of reasons. These activities include, but are not limited to, fishing, sand screen repair, perforating, pressure/temp flow monitoring, well logging, milling, maintaining well integrity (patching), and well stimulation.
Back in the 1980’s, Kratz and his colleagues at Cal Dive (now Helix ESG) performed the dangerous duties of subsea well intervention via hard hat diving, and in some cases they still do in the shallower waters of the North Sea. In deep water however, remotely operated vehicles and highly specialized technology is required.
This well intervention technology was thrust into the global spotlight during the 2010 Macondo Well blowout (aka BP Oil Spill) in the Gulf of Mexico. The Q4000 was the primary well intervention vessel used, and after the well was finally killed, the Q4000 raised the enormous Blow Out Preventer (BOP) to the surface with her 600T Multi Purpose Tower.
Beyond the Macondo disaster however, this critically important and specialized technology has largely sat in the shadows of offshore oil and gas production, but as the deep water market grows around the world, the market for these services follows along closely. The market for relatively inexpensive intervention vessels like the Q4000 is also positively influenced by the fact they can be used to drill top hole sections and are much more cost-efficient than the ultra-expensive deepwater drilling rigs for well intervention activities.
In a speculative move, Helix ESG has contracted Jurong Shipyard in Singapore to build an upgraded, and larger version of the Q4000. Very little details of this new vessel are available, however we do know that they will look to add the following capabilities:
- Through tubing well intervention
- Extended top hole drilling
- Riserless Mud Return
- Subsea Rotary Controlled Device
- Well flow back, well testing
- Subsea construction
- Subsea processing support
- Open water completions
Additionally, this vessel will have even better seakeeping characteristics than the Q4000, which is hard to beat considering the Q’s reputation. Mr. Kratz describes one such case:
“We’ve been locked into a well in 16 to 19 foot seas.
She’s really stable and the derrick is compensated. We’ve actually had a 100 ton load sitting on the seafloor in 16-foot seas and it’s been moving less than 1/8th of an inch.”
The new rig, he says, will have better characteristics, “she’s a larger vessel and will thus have better motions and be more stable than the Q4000.”
Regarding the scope of the work being done on the Q4000, Mr. Kratz comments:
“Most of it is inspection, we take the opportunity of having her out to do a large portion of our planned maintenance, and we do a continuous inspection program so we know pretty much what we’re going to do, and we plan that out. The only caveat is sometimes steel wastage can surprise you, but we’ve been surprised in a good way in that she’s only had about 1 percent loss of steel, which is not bad for a 10 year old vessel.
“How much longer do you expect the rig to be in drydock?” I asked,
“I think she’s due to go back in the water this week.”
Here are some images I took yesterday morning during our tour of the Q4000.