After a year of strong production growth in 2016, the five fields that make up the Western Satellites at the Prudhoe Bay unit all experienced declines this past year.
In a plan of development submitted to the state Division of Oil and Gas in late September 2017, BP Exploration (Alaska) Inc. reported declines in oil production at the Aurora, Borealis, Midnight Sun, Orion and Polaris fields at the west end of the Prudhoe Bay unit.
The declines put production from the year ending June 30, 2017, in line with production from the year ending June 30, 2015, suggesting that last year was something of an outlier.
BP files three plans of development each year for the Prudhoe Bay unit - one for the Initial Participating Areas early in the year, one for the Greater Point McIntyre Area in the middle of the year and one for the Western Satellites toward the end of the year.
Aurora
Aurora produced 4,696 barrels of oil per day in the year ending June 2017, down from 6,303 bpd the year before and up from 4,305 bpd during the 2014-15 reporting year.
BP brought the S-113BL1 well online in the second half of 2016 and performed a workover at the S-109 well in the first quarter of this year. The company also performed 42 workover operations at the Aurora field during the reporting year, although only four added production. The rest were for maintenance or to maintain production rates.
BP made no firm drilling commitments for the current year in its plan but said it had identified infill drilling targets. The workover program planned for the coming year is designed to maintain reservoir pressure in support of ongoing enhanced oil recovery activities, and to maintain production and mitigate declines, according to the company.
Borealis
Borealis produced 6,040 barrels of oil per day in the year ending June 2017, down from 8,517 bpd the year before and down from 8,768 bpd during the 2014-15 reporting year.
The company shut-in V pad production at the field in June 2016 in response to concerns over subsidence and potential piping stress. The company completed repairs on the facilities in late 2016 and returned all wells to production in the first quarter of this year.
The V pad repairs also impacted operations at the Orion field.
BP performed 61 workover operations at the Borealis field during the reporting year - 12 jobs added production, and the rest were for maintenance or to maintain production. A booster pump at Z-504B well ran reliably after a mid-2016 repair. A booster pump at Z-504A was repaired and returned to service this year after multiple electrical failures.
“The Borealis owners will continue to evaluate the optimal number of development wells and their locations throughout the life of the reservoir,” the company wrote in its plan.
The workover program planned for Borealis the coming year, through June 2018, is designed to maintain reservoir pressure in support of ongoing enhanced oil recovery activities, and to maintain production and mitigate declines, according to the company.
Midnight Sun
Midnight Sun produced 983 barrels of oil per day in the year ending June 2017, down from 1,134 bpd in the year prior and up from 964 bpd in the 2014-15 reporting year.
BP brought the P1-122i injection well into operation in October 2016, after a round of repairs. The company performed rate-adding activities on the E-101 and E-102 wells.
The plan includes no detailed program for drilling or workover activities for the reporting year ending June 2018. “As the waterflood continues to mature, sidetracking the producers within the pool to maximize oil recovery will be evaluated after the benefits from WAG (water alternating gas) injection are realized,” the company wrote in its plan.
Orion
Orion produced 3,469 barrels of oil per day in the year ending June 2017, down from 4,747 bpd in the year prior and 4,693 bpd during the 2014-15 reporting year.
BP performed 55 workover operations at Orion during the reporting year - nine added production, and the remainder was for maintenance or to maintain production rates.
The wells in the northwest corner of the Orion participating area have experienced high rates of downtime in recent years, in part because of sand production down hole.
The company is currently evaluating potential sidetracks at two shut-in wells - L-200 and L-205. The sidetrack designs could be useful for other wells in the troublesome region. The company included the projects in a previous plan of development. The current plan calls for drilling the L-205A sidetrack as soon as the fourth quarter of this year. The L-200A project requires mechanical repairs before drilling operations can be resumed.
A long-delayed I pad project at the Orion field remains dependent on economics and on resolving sand control technology in the region, according to BP. The proposed project at the overlapping Borealis and Orion fields was originally slated for 2006 and later postponed until 2010 and then pushed as late as 2020. In its current plan, BP said that it had “initiated a study to refresh the design and potential costs of an I Pad development.”
Polaris
Polaris produced 3,891 barrels of oil per day in the year ending June 2017, down from 4,306 bpd in the year prior and up from 3,890 bpd in the 2014-15 reporting year.
BP did not drill at Polaris during the last reporting year but performed 11 workover projects - two added production, the rest were for maintenance or to maintain production.
A potential viscous oil development at M pad and S pad remains under consideration, although the program depends on economics and the results of sand control technology trials. The program is being considered at the Orion field before the Polaris field.
