Department of Commerce, Community, and Economic Development
Alaska Oil and Gas Conservation Commission
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HomeMy WebLinkAbout2021 Northstar-Kuparuk Oil PoolHilcorp Alaska, LLC
Post Office Box 244027
Anchorage, AK 99524-4027
3800 Centerpoint Drive
Suite 1400
Anchorage, AK 99503
Phone: 907/777-8486
Joleen.oshiro@hilcorp.com
April 1st, 2022
Jeremy Price, Chair
Alaska Oil & Gas Conservation Commission
333 W. 7th Avenue, Suite 100
Anchorage, Alaska 99501-3539
RE: NORTHSTAR UNIT, NORTHSTAR FIELD, NORTHSTAR KUPARUK OIL POOL, STATE OF ALASKA,
2019 ANNUAL RESERVOIR REVIEW
Dear Commissioner Price:
In accordance with Conservation Order No. 739, Hilcorp Alaska, LLC (“Hilcorp”), as Operator, hereby submits for
your review the following Annual Reservoir Review for the Kuparuk Oil Pool in the Northstar Field.
This is the Annual Reservoir Review under Conservation Order No. 739 that corresponds to events during the 2021
calendar year. Note that the Northstar Field has been on production since November 2001, with the Kuparuk Oil
Pool beginning continuous production in November 2010.
A.Progress of Enhanced Recovery Project and Reservoir Management Summary
During 2021, no new wells were drilled or sidetracked in the Northstar Unit. Therefore the locations of all the wells
in the Northstar Unit have remained unchanged.
Production statistics are summarized in Table 1. Average daily oil production from the Kuparuk Oil Pool field was
2,571 bopd and average daily gas injection was 105.6 mmscfpd.
During 2021, the negative reservoir voidage was calculated at 1,122 thousand-reservoir barrels (MRB). Note that
lean gas re-injection began in wells NS-18 and NS-17 in January and October 2019 respectively. The average of
reservoir pressure for 2021 was 2,559 psia.
The reservoir simulation model with the geologic interpretation was created to continue progression of future
development scenarios of the Kuparuk reservoir. This model was matched to historical production, PVT analysis,
and reservoir pressure data gathered to date. It was utilized prior to the initiation of the lean gas reinjection project
as part of the approved by Kuparuk Area Injection Order (AIO) 41. The model studied the conversion of NS-18 to
injection and the recompletion of the NS-17 well into the Kuparuk C for additional lean gas injection capacity. This
will be continued to be used in 2021 to monitor the initial results of the EOR project and verify future producer and
gas injection location(s) to enhance ultimate recovery of the Kuparuk reservoir.
Page 2
B.Voidage Balance by Month of Produced Fluid and Injected Fluids – 2021
Table 1: NORTHSTAR KUPARUK OIL POOL
2021 OVERVIEW STATISTICAL SUMMARY
WELL STATISTICS
As of
12/31/2021 Full year (1)As of Dec-19 (2)
Producers 4 4
Injectors 2 1
NOTES:
(1) Well count data reflects ONLY those wells which contributed to production/injection during the respective year
(2) Active wells as of December 2021
PRODUCTION/INJECTION STATISTICS
Production 2021
Cumulative Start-Up through
12/31/21
Oil (BBL)938,449 9,431,130
Gas (MCF)55,321,067 365,084,455
Water (BBL)1,357,481 2,807,242
Injection
Water (BBL)0 0
Gas (MCF)38,532,131 120,654,529
Balance (excludes satellite well NS-34A and Ivishak Production)
Cum Production (MRB)3,695,977 24,867,373
Cum Injection (MRB)183,424 4,575,926
Over/Under (MRB)-3,512,554 -20,291,447
DAILY AVERAGE RATE DATA 2021
Production
Oil, BOPD 2,571
Gas, MCF/D 151,565
Water, BWPD 3,719
Injection
Water, BWPD 0
Gas, MCFPD 105,567
AVERAGE RESERVOIR PRESSURE
Average of surveys obtained in 2021 2,559 psia
Page 3
C.Summary and Analysis of reservoir pressure surveys within the pool
Static bottom hole pressures collected in 2021 are summarized below. Please note this data includes Ivishak
reservoir pressure data.
The average Northstar Kuparuk A & C reservoir pressure for 2021 is 2,559 psig, up 143 psig from the 2020 average.
These above pressures have been included with the historical Kuparuk reservoir pressure data and are graphically
represented in the next figure.
Month Oil, MRB Free Gas, MRB Water, MRB
Total
Voidage,
MRB
Year
Cum, MRB
Cum since
start-up, MRB
Formation
Gas, MRB
Flare &
Import
Gas, MRB
Total
Injection,
MRB
Year
Cum, MRB
Cum since
start-up,
MRB
Net
Injection,
MRB
Year
Cum, MRB
Cum since
start-up,
MRB
Jan-2021 0 297,360 103,549 297,360 297,360 21,468,756 349,696 0 349,696 349,696 2,351,306 52,336 52,336 -19,117,449
Feb-2021 0 321,943 101,829 321,943 619,303 21,790,699 303,855 0 303,855 653,551 2,655,162 -18,088 34,248 -19,135,537
Mar-2021 0 330,288 109,930 330,288 949,591 22,120,987 178,174 0 178,174 831,725 2,833,335 -152,115 -117,867 -19,287,652
Apr-2021 0 309,549 111,026 309,549 1,259,140 22,430,536 172,031 0 172,031 1,003,756 3,005,366 -137,517 -255,384 -19,425,169
May-2021 0 330,124 115,608 330,124 1,589,264 22,760,660 173,504 0 173,504 1,177,259 3,178,870 -156,620 -412,004 -19,581,790
Jun-2021 0 342,388 117,958 342,388 1,931,651 23,103,047 251,704 0 251,704 1,428,963 3,430,574 -90,684 -502,688 -19,672,474
Jul-2021 0 288,985 113,205 288,985 2,220,636 23,392,032 247,827 0 247,827 1,676,791 3,678,401 -41,158 -543,846 -19,713,631
Aug-2021 0 305,065 124,128 305,065 2,525,702 23,697,098 174,207 0 174,207 1,850,997 3,852,608 -130,859 -674,705 -19,844,490
Sep-2021 0 290,705 111,772 290,705 2,816,407 23,987,803 169,764 0 169,764 2,020,761 4,022,372 -120,941 -795,646 -19,965,431
Oct-2021 0 296,301 115,055 296,301 3,112,708 24,284,104 192,958 0 192,958 2,213,719 4,215,330 -103,342 -898,988 -20,068,774
Nov-2021 0 292,327 112,946 292,327 3,405,035 24,576,431 177,173 0 177,173 2,390,892 4,392,503 -115,155 -1,014,143 -20,183,928
Dec-2021 0 290,943 123,053 290,943 3,695,977 24,867,373 183,424 0 183,424 2,574,316 4,575,926 -107,519 -1,121,662 -20,291,447
2021 Totals 0 3,695,977 1,360,060 3,695,977 2,574,316 0 2,574,316 -1,121,662
Produced Fluids Injected Fluids
Net Injection
(Injection - Production)
6. Oil Gravity:
44 API/47 API
8. Well Name and
Number:
9. API Number
50XXXXXXXXXXXX
NO DASHES
10. Type
See
Instructions
11. AOGCC
Pool Code
12. Zone 13. Perforated
Intervals Top -
Bottom TVDSS
14. Final Test
Date
15. Shut-In
Time, Hours
16. Press.
Surv. Type
(see
instructions
for codes)
17. B.H.
Temp.
18. Depth
Tool TVDSS
19. Final
Observed
Pressure at
Tool Depth
20. Datum
TVDSS (input)
21. Pressure
Gradient, psi/ft.
22. Pressure at
Datum (cal)psig
NS-15 50029230730000 O 590150 Kuparuk 8,940'-8,994'1/1/21 528 SBHP 175 8,900 2,929 9,000 0.10 2,936
NS-07 50029230810000 O 590150 Kuparuk 9,002'-9,022'9/10/21 36 PBU 186 8,726 2,406 9,000 0.10 2,431
NS-13 50029230170000 O 590150 Kuparuk 8,875'-9,000'7/20/21 72 PBU 175 8,485 2,264 9,000 0.10 2,310
NS-19 50029231220000 O 590100 Ivishak 10,954'-11,069'5/8/21 183,384 SBHP 250 10,900 5,186 11,100 0.10 5,207
NS-09 50029230520000 O 590100 Ivishak 10,932'-11,030'7/24/21 600 SBHP 250 10,800 5,207 11,100 0.10 5,236
NS-11 50029233030000 O 590100 Ivishak 11,044'-11,095'7/24/21 144 SBHP 250 11,054 5,217 11,100 0.10 5,222
NS-20 50029231180000 O 590100 Ivishak 10,932'-11,030'12/21/21 23,544 SBHP 250 11,000 5,289 11,100 0.10 5,300
NS-14A 50029230260100 O 590100 Ivishak 10,893'-11,082'12/23/21 72 SBHP 253 11,000 5,309 11,100 0.10 5,319
NS-16A 50029230960100 O 590100 Ivishak 11,034'-11,108'12/24/21 108 SBHP 255 11,100 5,317 11,100 0.10 5,317
Comments:
Joleen Oshiro
23. All tests reported herein were made in accordance with the applicable rules, regulations and instructions of the Alaska Oil and Gas Conservation Commission.
I hereby certify that the foregoing is true and correct to the best of my know ledge.
Signature
Printed Name
Title
Date
Operations Engineer
March 2, 2022
STATE OF ALASKA
ALASKA OIL AND GAS CONSERVATION COMMISSION
RESERVOIR PRESSURE REPORT
1. Operator:2. Address:
Hilcorp Alaska, LLC 3800 Centerpoint Dr Suite 1400, Anchorage AK 99503
7. Gas Gravity:
Northstar Unit -11,100' TVDss/-9,000' TVDss 0.75
3. Unit or Lease Name:5. Datum Reference:4. Field and Pool:
Northstar Field/ Northstar Oil Pool &
Hooligan (Kuparuk) Oil Pools
Page 4
D.Results and Analysis of Production and Injection log surveys, tracer surveys, observation well
surveys and any other special monitoring
No new Kuparuk production profiles were obtained in 2021.
There was no other special monitoring for this reporting period.
E.Review of pool production allocation factors and issues over the prior year
Theoretical production is calculated for each Northstar producing well on a daily basis.
2021 Production Allocation Method
A well’s theoretical production is calculated using metered field volumes and hours on production as follows:
Gas Allocation
Gross Produced Gas = total return metered at test separator.
Net Produced Gas =Gross Produced Gas –Gaslift Gas.
Theoretical Produced Gas = all well tests Net Produced Gas prorated by the month.
(Proration calculation will include adjustments for shut in or downtime periods)
Field Gas Injection = metered prior to injection
Total Net Produced Gas =Field Gas Injection + Fuel Gas + Flare Gas + PPA Gas - Buy Gas
(Buy Gas = imported or Caribou Crossing acquired gas).
ܶݐ݈ܽ ܰ݁ݐ ܲݎ݀ݑܿ݁݀ ܩܽݏ
ܶℎ݁ݎ݁ݐ݈݅ܿܽ ܲݎ݀ݑܿ݁݀ ܩܽݏ = ܩܽݏ ܣ݈݈ܿܽݐ݅݊ ܨܽܿݐݎ
Gas Allocation Factor x Theoretical Produced Gas (individual well) =Allocated Gas (individual well).
Page 5
Oil Allocation
Actual Field Oil Production = oil volume metered by LACT (sold/delivered to Northstar crude oil pipeline)
(Adjusted for BS&W, temperature, and API gravity in accordance with API standards and BSEE regulations.)
Gross Produced Oil = total return metered at test separator.
Theoretical Well Oil Production = all well tests Gross Produced Oil prorated by the month.
(Proration calculation will include adjustments for shut in or downtime periods)
Theoretical Field Oil Production = Sum of Theoretical Well Oil Production
Field Natural Gas Liquid (NGL)Production = metered prior to commingling with oil
ܣܿݐݑ݈ܽ ܨ݈݅݁݀ ܱ݈݅ ܲݎ݀ݑܿݐ݅݊ +ܨ݈݅݁݀ ܰܩܮ ܲݎ݀ݑܿݐ݅݊
ܶℎ݁ݎ݁ݐ݈݅ܿܽ ܨ݈݅݁݀ ܱ݈݅ ܲݎ݀ݑܿݐ݅݊ =ܱ݈݅ ܣ݈݈ܿܽݐ݅݊ ܨܽܿݐݎ
Oil Allocation Factor x Theoretical Well Oil Production =Allocated Oil Production (individual well).
Water Allocation
Actual Field Water Production = water volume metered prior to injection disposal
Net Field Water Production = Actual Field Water Production – Metered Grey Water
Gross Produced Water = total metered at test separator.
Theoretical Well Water Production = all well tests Gross Produced Water prorated by the month.
(Proration calculation will include adjustments for shut in or downtime periods)
Theoretical Field Water Production = Sum of Theoretical Well Water Production
ܰ݁ݐ ܨ݈݅݁݀ ܹܽݐ݁ݎ ܲݎ݀ݑܿݐ݅݊
ܶℎ݁ݎ݁ݐ݈݅ܿܽ ܨ݈݅݁݀ ܹܽݐ݁ݎ ܲݎ݀ݑܿݐ݅݊ =ܹܽݐ݁ݎ ܣ݈݈ܿܽݐ݅݊ ܨܽܿݐݎ
Water Allocation Factor x Theoretical Well Water Production =Allocated Water Production (individual well).
Northstar field allocation factors for 2021 averaged 1.25 for oil, 0.76 for water and 0.72 for gas. Oil allocation
factor was high due to allocation of NGL production. This data includes all Ivishak producers as well.
F. & G. Future Development Plans & Review of Annual Plan of Operations and Development
A full field study of the Northstar Kuparuk Reservoir was continued in 2021, with an emphasis on gas importation
for pressure maintenance. Well histories, review of production and injection data, material balance calculations,
geological, and geophysical work were updated.
Projects completed during the 2021 calendar year:
o NS-07 Perf add in the Kuparuk C sands
o NS-08 Perf add in the Kuparuk A sands
Projects planned for the 2022 calendar year:
In 2021, Hilcorp will pursue increased unit production through additional well intervention projects, any necessary
infrastructure and facility repairs, and other optimization opportunities as they arise.
No drilling activities are planned at Northstar within the 2021 calendar year.
Hilcorp is continuing to update the reservoir model to analyze the economics and viability of PBU gas imports to
maintain pressure in the Kuparuk reservoir. Facility gas debottlenecking projects are currently being reviewed in
conjunction with the gas importation feasibility study.
Page 6
Sincerely,
Anthony McConkey
Reservoir Engineer - Northstar
