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The corner play Fourth Prudhoe satellite kicks production above 41,000 bpd: BP brings on solid production in western Prudhoe Bay, at junction of three units Kristen Nelson PNA Editor-in-Chief
A $100 million project to develop satellite fields on the western side of Prudhoe Bay is well into development drilling — and producing more than 40,000 barrels a day.
A map of well bottomhole locations at the boundary of the Milne Point, Kuparuk River and Prudhoe Bay units on the central North Slope shows largely blank.
That is where work is taking place on five satellites, BP Exploration (Alaska) Inc.’s Gilbert Beuhler, greater Prudhoe Bay satellite resources manager, and reservoir engineer Frank Paskvan told PNA April 18.
The work began at Midnight Sun, with production in 1998, followed by Polaris production that same year, Aurora in early 2001 and Borealis last November. Appraisal drilling is under way at Orion, the fifth of the satellites, and development drilling is expected to begin there next year.
The latest production figures from the Alaska Oil and Gas Conservation Commission, for March, show cumulative production of some 12 million barrels from the satellites: 5.5 million barrels from Midnight Sun, which has three producing wells; 1 million barrels from Polaris, with four wells; 2.5 million from Aurora, which has seven wells; and 2.9 million barrels from the newest of the fields, Borealis, with 10 producing wells.
Work at Midnight Sun is complete and Aurora is complete except for development drilling. Polaris and Borealis have development plans, but lack approved participating areas; development drilling continues at both fields. Orion is being appraised. Jump in production The satellite fields saw a big jump in production, to a peak of 45,000 barrels a day, after Borealis came on line in November, Beuhler said, “a big change from us, because two months before that we had been producing roughly 10,000 barrels a day. So it was a very rapid ramp up.” The initial peak in production was 30,000 bpd from six Borealis wells.
Production dropped off a bit, he said, but with more wells drilled it has come back up to about 41,000 barrels a day.
The satellites are in the Prudhoe Bay unit, but produce from separate pools.
The Midnight Sun, Aurora and Borealis satellites produce from the Kuparuk River formation, but the pads also have wells to the deeper Ivishak, the main producing formation at Prudhoe Bay.
The Polaris and Orion oil pools are the shallowest, producing viscous Schrader Bluff oil. Shared facilities Production is from new and existing pads in the western Prudhoe area and multiple reservoirs are produced at an individual pad.
“S pad was originally built to be an Ivishak production facility,” Paskvan said. “Since then we’ve drilled Kuparuk and Schrader Bluff wells from that pad — so you’ve got all three pools or fields producing through shared drill sites, pads, production flow lines and gathering centers.”
The area of active development, the western development area and Midnight Sun, includes two new drill site pads, L pad and V pad.
“These are the first new pads coming on line in Prudhoe in over 10 years — and the first ever for satellite development,” Beuhler said.
And the first well drilled at L pad “was an Ivishak well,” Paskvan said. Since then, Kuparuk formation wells have been drilled from the pad, he said.
“We manage multiple reservoirs,” said Beuhler. “For example on L pad, we have three reservoirs available to us: the Ivishak, the Kuparuk and the Schrader, from bottom up.”
Accessing multiple polls from one pad “promotes a very efficient development,” he said. Drilling to two or three reservoirs from the same pad, “allows us to maximize production from a limited footprint of gravel and limited production facilities.” Enhanced well productivity Beuhler said they are drilling two main types of wells in the satellite fields. All of the wells are directional, he said, curving out from the pad to reach their targets. “Most of the Kuparuk wells are conventional vertical wells,” he said, with producers fractured to enhance productivity.
There are also some vertical fractured wells in the Schrader, but the exciting opportunity for enhanced production in the viscous oil Schrader Bluff formation is high-angle wells customized to the oil target, he said.
“What high angle means is in the reservoir interval itself… as you enter the reservoir itself, you go high angle — which means you go sideways.” A single well bore “can then access a long distance of reservoir, so you have one well bore that might access three or four thousand feet of reservoir… So it takes less well bores to develop the reservoir,” Beuhler said.
In a single production sand, Paskvan said, you could drill 500 feet or as much as two or three thousand feet horizontally through the producing sand. 2002 active for satellites V pad startup was in March, Beuhler said, the first Orion well came on in March, water flood is expected to start up in the Borealis satellite as soon as approval is received from the Alaska Oil and Gas Conservation Commission and water flood is expected to start in the Polaris satellite in the third quarter.
Some of the satellite accumulations can be drilled from existing pads and appraisal wells were drilled from ice pads in the winter, Beuhler said, allowing appraisal of the reservoirs. L and V pads were started in 2000, L pad was finished in November and V pad in March.
“Roughly in the last seven months,” Beuhler said, “we’ve had two new pads start up, all the infrastructure of the pipelines and … associated with that two new field start ups, the Borealis field in November and the Orion field this March.” Also IPA business “These pads allow access to all the new opportunities — both the new satellites as well as … Prudhoe unit business,” Beuhler said.
The $100 million investment is cumulative over several years, he said, and represents the two new pads, gravel and manifold equipment.
Also included, Paskvan said, are the 24-inch production pipeline, the 12-inch water injection line and the 8-inch gas lift line, as well as power and instrumentation cables.
Now that there is facility infrastructure in the area between the Milne Point, Kuparuk River and Prudhoe Bay units, Beuhler said, there will be a fairly active drilling program in the area over the next few years. Two rigs are currently drilling satellites.
In addition, there are opportunities for new pads. Beuhler said a well was drilled to the Schrader from an ice pad in February just south of the Milne Point line, “so we’re actively progressing appraisal for decisions like that… looking for oil in the reservoir — and those are what would lead to pad decisions.”
There are some 30 wells into the satellites now, about two dozen of them producers. Orion under appraisal Orion is being appraised now, Beuhler said. “And the ice well that we drilled in February and March is just the next appraisal of that” and there will probably be more reservoir delineation at Orion before a decision is made that the reservoir is commercial.
Paskvan said that because Borealis is 1,500 to 2,000 feet deeper than the Schrader Bluff horizon — Orion is a Schrader Bluff accumulation and Borealis is Kuparuk — as the Borealis wells are drilled, “you go through the interval where the Orion accumulation is.”
While producing wells are specific to a single satellite, the injectors, Paskvan said, have been approved “as co-mingled dual injectors and so you share the well bore, minimize your surface facilities and then dual inject…” to offset producers in different horizons.
“We still have to go forward and drill the offset producers, and get approval to start a water flood out in that horizon, but we’re investing now to set us up to efficiently use those well bores. That’s the best time to do that, when you originally drill the well,” he said.
Four of the five satellites are in active development and reservoir management, Beuhler said, with “active development drilling, drilling producers, injectors, water flood startup and reservoir management of those floods.”
There will be additional appraisal drilling at Orion to assess the limits of the reservoir and determine if there is a commercial opportunity there, he said.
Everything goes to existing Prudhoe facilities for processing, he said, and “what it allows us to do is take the same piece of facility at Prudhoe, a process facility, and produce all these barrels through it.
“There’s synergy in that, because you are using existing facilities and producing new and additional barrels, so you’re sharing the load in terms of the infrastructure,” Paskvan said, which is an advantage to the entire field. What’s new “You don’t get the opportunity to develop a brand new reservoir too often, especially at Prudhoe,” Beuhler said. “So what we’re doing is we’re trying to capture the facility learnings and well bore design, the high-angle wells, deviated drilling.”
The Schrader being developed at Polaris and potentially at Orion is an area where the satellites are watching what Milne Point is doing with their Schrader development, Beuhler said. The western satellite Schrader is lighter oil than at Milne Point and Kuparuk, Beuhler said, “because it is a little bit deeper, a little bit hotter…”
But it’s still viscous. “It’s challenging, definitely technically challenging,” he said.
“The reservoirs are challenging, the oil quality is challenging, so definitely we look at things like extended reach drilling with high-angle wells…”
The Milne Point program is using multi-lateral wells, penetrations of two different producing sands from the same well bore, Beuhler said, and that technology is being looked at for viscous oil in the western satellites. One Polaris well being considered would even have three penetrations from a single well bore, to reach stacked Schrader Bluff sands.
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