September ANS production bounces back

Month-to-month increase of 27.8 percent as Alpine comes back up after shutdown, new transit line in operation from Prudhoe FS-2

Kristen Nelson

Petroleum News

Alaska North Slope crude oil production averaged 705,360 barrels per day in September, up a dramatic 27.8 percent from an August average of 552,114 bpd.

The biggest month-over-month change, an increase of 100.6 percent, was at the ConocoPhillips Alaska-operated Alpine field which was offline during a good part of August for planned maintenance, work that overlapped with the second planned trans-Alaska oil pipeline shutdown of the summer.

ANS September average production was comparable to May, and the highest since then. In additional to some reduction in production because compressors operate less efficiently in warmer weather, there was a lot of planned maintenance on the North Slope over the summer.

There were field shutdowns at the end of June due to planned trans-Alaska pipeline maintenance. In July there was major maintenance at Prudhoe Bay with two of the field’s seven processing centers offline a good part of the month and a planned shutdown at the Kuparuk River field of two of the field’s three central processing facilities.

Alpine, which averaged 122,844 bpd in September, averaged only 61,617 bpd in August — the field routinely produces well over 100,000 bpd; average production in September 2007 was 126,202 bpd. Alpine production includes Fiord and Nanuq satellite production.

No FS-2 oil in Endicott line

The October average for Endicott will drop even more as the Endicott line goes back to its normal load of oil from the Duck Island unit. The Endicott pipeline has been playing host to some 33,000 bpd of Prudhoe Bay Flow Station 2 oil. Volumes on the line dropped substantially in mid-September and then leveled off at around 15,000 bpd as BP put its new transit line in service for FS-2 crude oil.

“In mid-September the outboard leg of the western transit line, Flow Station 2 to Flow Station 1, was placed in service,” BP Exploration (Alaska) spokesman Steve Rinehart told Petroleum News in an e-mail. The 12-diameter-line is some three miles long, he said.

Those three miles are part of the 16 miles of sales oil transit lines at Prudhoe Bay that BP began replacing after the company found corrosion in a transit line in August 2006. Workers were inspecting pipe anomalies identified in a pig run and found oil-stained pipeline insulation as they removed it for testing; they later found a small leak.

BP shut down the eastern operating area at Prudhoe. The company then began shipping some Prudhoe oil through bypass lines — such as the bypass that took FS-2 oil to the Endicott line — until new oil transit lines, lines that carry oil which has had natural gas and water removed and is ready for shipment down the trans-Alaska oil pipeline to market.

Rinehart said the outer leg in the western operating area, also some three miles long, came online last spring. The other two sections of new oil transit lines, east and west, are expected to be in service before the end of the year, he said.

Other fields up

The largest increase was at the BP-operated Prudhoe Bay field, which averaged 325,689 bpd in September, a 36.9 percent increase over an August production average of 237,951 bpd. A portion of that increase comes from the mid-month switch to the new transit line, which resulted in FS-2 barrels showing up correctly in Department of Revenue figures as part of Prudhoe Bay production.

Prudhoe Bay production includes satellite production from the Aurora, Borealis, Midnight Sun, Orion and Polaris fields.

The ConocoPhillips Alaska-operated Kuparuk River field averaged 134,886 bpd in September, up 11.2 percent from an August average of 121,331 bpd. Kuparuk production includes Tabasco, Tarn, Meltwater, West Sak — and the Pioneer Natural Resources Alaska-operated Oooguruk field, which produces through Kuparuk facilities. Oooguruk has been shut in for most of the summer due to a 45-day planned maintenance at Kuparuk’s Central Processing Facility 3; the field came online in June at some 2,000-3,000 bpd.

The BP-operated Lisburne field (part of Greater Prudhoe Bay) averaged 25,279 bpd in September, up 9.7 percent from an August average of 23,035 bpd, but still well below the field’s normal production rate of more than 30,000 bpd. Lisburne was down at the end of August for a valve change out on an inlet line, resumed normal volumes in early September and then was down completely for five days near the end of September. Rinehart told Petroleum News that there were a series of repairs at Lisburne, “none particularly significant but located in places that required the plant to be taken offline.” After sporadic production late in September and early in October the facility topped 30,000 bpd Oct. 5.

The BP-operated Northstar field averaged 32,088 bpd in September, a 2.71 percent increase over an August average of 31,241 bpd.

BP’s Milne Point field averaged 31,644 bpd in September, up 1.2 percent over an August average of 31,276 bpd. Milne Point includes Sag River and Schrader Bluff production.

The September temperature at Pump Station 1 on the North Slope averaged 36.3 degrees Fahrenheit, compared to 43.1 degrees F in August.

Cook Inlet production averaged 13,242 bpd in September, down 0.3 percent from an August average of 13,282 bpd.