The race often goes, not to the fastest car, but to the one that makes the fewest pit stops.

The race is on between those intent on minimizing the need for intervention and those intent on trying to make intervention a more pleasant experience. On one side are companies working in the world of production optimization, trying to get the most oil and gas out of the reservoir as fast and as economically as possible, and with the highest economic recovery factor. On the other side are the mechanical wizards who continue to amaze us with faster, cheaper, simpler and lighter-weight intervention tools and systems.
Each side has its specialists. At the recent Offshore Technology Conference, lines were drawn between the flow assurance teams and those devising new deepwater intervention techniques, between the reservoir optimization gurus and the coiled tubing consortia. It's the age-old battle between problem prevention and problem solving.

Intec Engineering sponsored a flow assurance panel comprised of both majors and independents. They explored four areas: thermal management, chemicals, processing and hardware, and tools and techniques. Most urged a holistic approach that considers everything that happens to a drop of oil from the time it leaves the reservoir until it departs from the export pipe. This approach will identify and help companies focus on the technology gaps. Industry-wide cooperation is essential. Susan E. Lorimer, senior staff engineer with Shell's Subsea & Pipeline-Subsea Systems, stressed, "Today's technology gaps exceed the capabilities of any single operator."

There's plenty of work for everyone, with many solutions well underway. Interestingly, the area with the least amount of progress is development of predictive tools that will help designers anticipate and deal with problems before they become costly or bothersome. However, strong R&D efforts are currently ongoing.

In deepwater, temperature and distance seem to be the biggest challenges. It's one thing to tie a few closely spaced satellite wells together. It's quite another if they are separated by several kilometers of frigid seascape.

Meanwhile, on the surface, engineers are trying to develop smaller, more agile well servicing vessels that can perform interventions, even in deepwater, without the necessity of mobilizing a rig. A few such vessels exist and are on trial, primarily in the North Sea. Strong, versatile, coiled tubing plays a leading role in these efforts. Presently, most subsea intervention operations are helped by ROVs, but even these workhorses are being scrutinized to see if there is a way to enter and exit the wellhead unassisted. At the other end of the spectrum are the deepwater semisubmersible intervention vessels like Cal Dive's Q-4000 behemoth. Purpose-built, theQ-4000 can perform the most rigorous intervention duties in both deepwater and rough seas. Who will win, the tortoise or the hares?

At the seabed, tree manufacturers are hedging their bets. The latest trees are configured to support flow assurance equipment and intelligent well completions, two of the fastest growing solutions on the problem prevention side. At the same time, modern subsea trees are designed to facilitate intervention, with full-bore vertical access connectors that can accept a variety of hardware, including rigless techniques.

Arguably, one of the most interesting areas with implications on intervention reduction is subsea processing. A full spectrum of equipment, mostly modular, has been developed or is near completion. A laundry list of subsea modules includes the full line of separators (oil/water, liquid/gas, liquid/sand), multiphase booster pumps, compressors, dehydration units, mixers, heaters, coolers, chemical treatment units, and recirculation or injection pumps.

Trying to keep track of everything are the intelligent well specialists who depend on their abilities to monitor, measure and modify production, thus holding off intervention. Again using a systems approach, these folks have the ability to monitor key parameters at the completion itself, at the tree or in the processing modules. They even have permanent in-well fiber-optic seismic arrays that can look deeply into the formation to map reservoir drainage patterns. Using 4-D seismic techniques, they can manipulate drainage by varying production rates from each well in the system, sometimes switching injectors and producers to delay water or gas encroachment as long as possible.

The green flag is waving. Whether the winner is prevention or solution remains to be seen. I suspect we will see some optimized result, where the real winner will be the green car with the $$$ logo on it.



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