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Alpine production averaging 5,000 barrels per day above expected levels Wells have been successful, reservoir a bit better than expected and facility has been tweaked to handle above average 80,000 bpd design Kristen Nelson PNA Editor-in-Chief
Production at Alpine has surpassed expectations. Operational tweaking and de-bottlenecking are allowing the facility to handle throughput averaging 85,000 barrels per day — 5,000 bpd above the 80,000 bpd average production the facility was designed to handle, and field operator Phillips Alaska Inc. has begun a study to determine whether a facility upgrade is warranted.
“We’ll probably average a bit over 85,000 barrels for the whole year. And we’ve got a one-day record production rate for a day of 102,962 barrels of oil” set Sept. 10, Mark Ireland, Phillips’ western North Slope subsurface manager, told PNA Sept. 20.
“But we can’t do that day in and day out — that was kind of a best single day,” he said.
Several things — the facility, the operations staff and the wells — have combined to make the higher production rate possible.
The project team did “an excellent job designing and building the facility,” allowing production rates above the original design plans, Ireland said, but probably the biggest factor in achieving the 85,000 bpd rate is that the operations staff learned “how to operate that plant and manage those high of flow rates through the plant. And that’s not an easy job by any means.” In the zone 96 percent of the time On the subsurface side, “we’ve been very successful with the wells we’ve drilled performing at higher than expected rates.”
Part of that well performance, Ireland said, comes from “reservoir quality being a wee bit better than expected.” But, he said, the well performance is due “more to hard work and execution than to blind luck.”
Alpine is being developed with horizontal wells — averaging 3,000 horizontal feet through the reservoir. In the area of the first pad, Colville Delta 1, Ireland said, “some of the reservoir thickness may be anywhere from 20 to 60 feet thick. So some of those targets we’re going after are relatively thin.”
And it takes considerable drilling to get to those targets.
“The formation is about 7,000 feet underground. So we’re coming down 7,000 feet and in some cases we’re reaching out say another 10,000 feet or farther and then, once reaching the formation, then we drill horizontally for 3,000 — we’ve got about three wells that are over 5,000 feet.”
In any field, the geology changes, and you expect that you “get out of the zone and have to re-drill part of it,” Ireland said.
At Alpine the wells have stayed in the producing zone 96 percent of the time.
“That’s been one of the real successes of the team,” he said.
The first drill site, CD1, in the eastern half of the field, is the source of current production.
“And that is the highest quality reservoir that we expect to see,” Ireland said. There are 18 wells producing and 18 wells injecting at CD1.
“On the best days, we’re averaging over 5,000 barrels a day per well.” Debottlenecking at facilities In addition to drilling success, the design quality and the ability of operations people in learning to put that much oil through that plant is the other big piece, Ireland said.
Learning to operate the plant at the higher rate involved learning “the behavior of the wells and the equipment” so the plant could be operated at the higher level “and still operate in a very safe and controlled manner,” he said.
Then there have been a series of small things — some de-bottlenecking and small things tweaked — to allow Phillips to reach that 85,000 bpd average.
“You see what the limitation is and then find a way to address it — either replace somethi%ng mechanically or make it a little bit bigger if that’s the bottleneck for the system, or learn to operate that piece of equipment in a different manner that allows you to put more oil through it. And then go on and find that next limitation that they bump up against and go through the same kind of process.”
The limit of tweaking and de-bottlenecking has pretty well been reached, he said.
“They’ve gotten the vast majority of the learning they can get and the improvements they can make with the facilities that exist today. That’s already occurred,” Ireland said.
Phillips is now studying expanding the capacity of the plant and sometime in the second quarter next year will make a decision on whether or not to go ahead.
With the little bits and pieces done, Ireland said, “now it would be major pieces of equipment that would have to be replaced or lines replaced, that sort of thing. Additional pumps brought in.” CD2 construction complete Construction is complete at CD2, the fourth producing well there was just completed there and wells are being prepared for startup, expected in October.
“And that won’t mean any extra production, because the limitation is how much oil we can put through the plant and down the pipeline,” Ireland said.
Production from CD2 goes to the Alpine facility, and when CD2 production begins, Ireland said, “we’ll reduce the production rates out of the wells at CD1.”
Beyond CD2 production, Nanuq and Fiord production is also planned to go through the Alpine facility when they start up three or four years from now.
Permits have been filed for those developments, Ireland said, and if all goes well Phillips will start to put gravel down for those developments in winter 2003.
“But they would basically be brought on to try to keep the plant full for longer into the future. They won’t actually increase the plant rate. They’ll be just like the satellite fields at Prudhoe or Kuparuk. They’re trying to keep those rates relatively stable, but coming through the same set of facilities,” he said.
Doyon rig 19 is drilling at CD2 now. The majority of the CD1 wells, 36, have been drilled. Four of the producing wells at CD2 are completed. There are 110 wells planned for the field, producers and injectors.
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