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Drilling success prompts Phillips to accelerate pace at West Sak The first of three horizontal multilateral wells was expected to produce 600 barrels a day but instead is producing 800 barrels; a higher capacity pump could take it to 2,000 barrels, says project manager Steve Bross Kay Cashman Editor-in-Chief
In June, Phillips Alaska Inc. resumed drilling at the West Sak heavy oil project in the southwest corner of the North Slope Kuparuk River field. A high production rate from 1D-102, the first of three horizontal multilateral wells the company was budgeted to drill this year, prompted Phillips to increase the pace of its drilling program at West Sak.
“We had hoped for an average of 600 hundred barrels a day. ... Our first well — which had two-3,000 foot horizontal laterals — came on at over 1,000 barrels a day,” Phillips heavy oil manager Steve Bross told PNA in mid-October. “It stabilized at about 800 barrels per day. That was to some degree pump limited. ... After the well has been in production a few months, we’re going to do some draw down tests ... and check the quality of the completion. When we do that we’ll upgrade the pump ... replace it with a higher capacity pump.”
How much more oil per day could Phillips get with a different pump?
Bross said 2,000 barrels a day was realistic.
“We could have changed the pump right away but the drillers on the Nordic 3 were so proud of the well that they didn’t want us to touch a thing,” he said.
Before this success, Bross and his people had envisioned a program in which they’d drill “three to four wells every couple years.” In between, they expected to evaluate the results and decide on the approach for the next set of wells. On the right track “Now we think we’re on the right track with horizontal multilaterals ... to access West Sak’s B and D sands. That’s where 60 percent of the West Sak resource lies,” Bross said. The second well, he said, looks to be stabilizing at just under 800 barrels per day.
Phase 1 of the West Sak program — initiated in 1997 by Phillips Alaska predecessor ARCO Alaska Inc.— resulted in 19 producing, conventional wells that penetrated B, D and the deeper A sands. Those wells are averaging about 300 barrels per day.
Although technically challenging, the horizontal wells, Bross said, get better drainage and better recovery than the single bore, rotary drilled wells.
Next year, in Phase 3 of the West Sak program, Phillips hopes to get approval from its other partners in Kuparuk — mainly BP Exploration (Alaska) Inc. and Exxon Mobil Corp. — to drill five or six more multilaterals.
It’s a “very aggressive program,” Bross said. “We should have budget approval in November. ... That will basically keep one rig working all year.” Getting the costs in line Bross is hoping to drill next year’s multilateral horizontals for less than twice the cost of West Sak’s single, conventional wells, which cost about $2.7 million each.
“We wanted to drill this year’s wells for $4 million each and they’re costing us over $5 million each, but our rates are higher and the significant thing to note is that we’re on the learning curve. For example, it took 35 trips in and out of the hole to get this well drilled. We took that many trips because we try to be conservative — we don’t want to take any real risks. The whole goal of the program is to prove up the deliverability of this type of completion, so we didn’t want to try to cut any corners.
“As our confidence grows, we will be able to reduce the number of trips, do things faster. ... I think $4 million per well is do-able.” Bross said.
As PNA goes to press, Phillips is close to finishing its third well this year. Sharing technology with BP One factor in reducing the costs of developing the West Sak resource is the technology sharing that Phillips and BP, operator of the Schrader Bluff heavy oil project, have been doing.
“There are many similarities between Schrader Bluff and West Sak,” Bross said. “We share data with BP. ... We try not to duplicate each other. What we learn here we give them so they don’t have to repeat what we’ve done. ... BP has already drilled one horizontal. And they’re going to drill a multilateral.”
While Bross and his people are experimenting with multilateral drilling and a combination of new technologies, such as a new set of tools that are right at the bit (GEO steering technology), “BP is trying to cut some money out of the window system. They’re running a different window system than we are. They’re not going to run screens like we are. ... We spent over a million dollars circulating fluids just to clean these holes up before we run that screen. ... We spend days, almost a week, just circulating and cleaning because if you run that screen into the hole and you’ve got a big mud cake left in the hole, it will plug the screen. The screens we use are very expensive, so we might be able to cut some money out there,” Bross said. Bigger pump, 4,000 foot laterals “We actually get a pretty good feel for how this third well is going to perform,” Bross said. “When we first started the program people would look at us funny if we said we were going to put a pump that can handle 1,000 barrels a day in the West Sak. We took a lot of ribbing over that, so it was kind of gratifying to say, ‘hey, we’re pump loaded’ on the second day that the well was producing.”
Bross is going to put “a big pump” in the third well. A “really big pump. We’re taking both laterals to 4,000 feet,” he said.
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