Department of Commerce, Community, and Economic Development
Alaska Oil and Gas Conservation Commission
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HomeMy WebLinkAbout2020 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, 2021
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 2020
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 2020, 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
3,025 bopd and average daily gas injection was 149.8 mmscfpd.
During 2020, the negative reservoir voidage was calculated at 4,222 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 2020 was 2,416 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 2020 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 – 2020
Table 1: NORTHSTAR KUPARUK OIL POOL
2020 OVERVIEW STATISTICAL SUMMARY
WELL STATISTICS
As of 12/31/2020 Full year (1)As of Dec-20 (2)
Producers 4 4
Injectors 2 2
NOTES:
(1) Well count data reflects ONLY those wells which contributed to production/injection during the respective year
(2) Active wells as of December 2020
PRODUCTION/INJECTION STATISTICS
Production 2020
Cumulative Start-Up through
12/31/20
Oil (BBL)1,107,020 8,493,496
Gas (MCF)63,197,304 246,261,189
Water (BBL)942,675 1,450,019
Injection
Water (BBL)0 0
Gas (MCF)54,817,994 82,061,132
Balance (excludes satellite well NS-34A and Ivishak Production)
Cum Production (MRB)4,222 20,888
Cum Injection (MRB)3,662 5,482
Over/Under (MRB)-560 -15,405
DAILY AVERAGE RATE DATA 2020
Production
Oil, BOPD 3,025
Gas, MCF/D 172,670
Water, BWPD 2,576
Injection
Water, BWPD 0
Gas, MCFPD 149,776
AVERAGE RESERVOIR PRESSURE
Average of surveys obtained in 2020 2,416 psia
Page 3
C.Summary and Analysis of reservoir pressure surveys within the pool
Static bottom hole pressures collected in 2020 are summarized below. Please note this data includes Ivishak
reservoir pressure data.
The average Northstar Kuparuk A & C reservoir pressure for 2020 is 2,416 psig, down 141 psig from the 2019
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-2019 0 375,024 69,271 375,024 375,024 17,040,571 181,849 0 181,849 181,849 2,001,951 -193,176 -193,176 -15,038,620
Feb-2019 0 348,931 69,119 348,931 723,956 17,389,503 185,648 0 185,648 367,497 2,187,600 -163,283 -356,459 -15,201,903
Mar-2019 0 371,775 74,538 371,775 1,095,731 17,761,278 348,825 0 348,825 716,322 2,536,425 -22,950 -379,409 -15,224,853
Apr-2019 0 352,071 68,048 352,071 1,447,802 18,113,349 330,622 0 330,622 1,046,944 2,867,047 -21,449 -400,858 -15,246,302
May-2019 0 334,378 73,695 334,378 1,782,181 18,447,727 333,842 0 333,842 1,380,786 3,200,889 -536 -401,394 -15,246,839
Jun-2019 0 364,707 77,258 364,707 2,146,887 18,812,434 317,330 0 317,330 1,698,116 3,518,219 -47,377 -448,772 -15,294,216
Jul-2019 0 385,137 79,952 385,137 2,532,025 19,197,572 328,328 0 328,328 2,026,444 3,846,547 -56,809 -505,581 -15,351,025
Aug-2019 0 369,012 83,478 369,012 2,901,036 19,566,583 324,743 0 324,743 2,351,187 4,171,290 -44,268 -549,849 -15,395,293
Sep-2019 0 350,897 85,442 350,897 3,251,933 19,917,480 317,381 0 317,381 2,668,568 4,488,671 -33,516 -583,365 -15,428,810
Oct-2019 0 331,884 77,629 331,884 3,583,818 20,249,365 321,714 0 321,714 2,990,282 4,810,385 -10,170 -593,535 -15,438,980
Nov-2019 0 359,808 90,906 359,808 3,943,626 20,609,173 327,087 0 327,087 3,317,370 5,137,473 -32,721 -626,256 -15,471,700
Dec-2019 0 278,560 95,128 278,560 4,222,185 20,887,732 344,997 0 344,997 3,662,367 5,482,470 66,438 -559,818 -15,405,262
2020 Totals 0 4,222,185 944,465 4,222,185 3,662,367 0 3,662,367 -559,818
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-06 50029230880000 O 590100 Ivishak 10,873'-11,162'7/19/20 1584 SBHP 255 11,100 5,301 11,100 0.19 5,301
NS-07 50029230810000 O 590150 Kuparuk 9,002'-9,022'10/22/20 66 PBU 187 8,726 2,458 9,000 0.09 2,483
NS-12 50029230910000 O 590100 Ivishak 10,995'-11,077'10/23/20 72 SBHP 252 11,000 5,246 11,100 0.09 5,256
NS-13 50029230170000 O 590150 Kuparuk 8,875'-9,000'10/9/20 116 PBU 175 8,485 2,302 9,000 0.09 2,348
NS-14A 50029230260100 O 590100 Ivishak 10,893'-11,082'10/14/20 360 SBHP 254 11,000 5,327 11,100 0.09 5,336
NS-16A 50029230960100 O 590100 Ivishak 11,034'-11,108'7/20/20 96 SBHP 254 11,100 5,358 11,100 0.10 5,358
NS-19 50029231220000 O 590100 Ivishak 10,954'-11,069'10/13/20 13,800 SBHP 253 10,900 5,216 11,100 0.10 5,339
NS-20 50029231180000 O 590100 Ivishak 10,932'-11,030'4/22/20 8928 SBHP 250 11,000 5,369 11,100 0.09 5,379
NS-21 50029231260000 O 590100 Ivishak 11,012'-11,099'4/23/20 72 SBHP 250 11,000 5,355 11,100 0.10 5,365
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 knowledge.
Signature
Printed Name
Title
Date
Reservoir Engineer
January 15, 2021
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 2020.
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.
2020 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).
Page 5
ܶݐ݈ܽ ܰ݁ݐ ܲݎ݀ݑܿ݁݀ ܩܽݏ
ܶℎ݁ݎ݁ݐ݈݅ܿܽ ܲݎ݀ݑܿ݁݀ ܩܽݏ =ܩܽݏ ܣ݈݈ܿܽݐ݅݊ ܨܽܿݐݎ
Gas Allocation Factor x Theoretical Produced Gas (individual well) =Allocated Gas (individual well).
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 2020 averaged 1.56 for oil, 0.75 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
In 2020, Hilcorp increased unit production through well intervention projects, and other optimization
opportunities, that included the evaluation of shut-in wells for potential return to service. The full field study of
the Northstar Kuparuk Reservoir was continued. Well histories, review of production and injection data, material
balance calculations, geological, and geophysical work were updated. The Kuparuk geological model was created
with a reasonable history match. This model was utilized to progress the development plans of the Kuparuk
reservoir, including the initiating of lean gas reinjection into the Kuparuk with the conversion of NS-18 and the
recompletion of the NS-17 well in 2019.
Projects completed during the 2020 calendar year:
·NS-17 - Performed RWO recompletion from the Ivishak reservoir gas injector to a lean gas injection well in the
Kuparuk C reservoir. (October 2019 RWO executed, February 2020 initial put on injection)
·Northstar Propane Chiller Project
o Performed a feasibility study, economic analysis, and sanctioned chiller project to improve NGL
recovery during warmer ambient temperatures; and (February 2019)
Page 6
o Began the necessary infrastructure, facility modifications and tie-ins for this project. (September 2019
and ongoing).
Projects planned for the 2021 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 will continue update the full field study of the Northstar Unit. This may include re-mapping productive
horizons, updating well histories, reviewing production and injection data, material balance calculations, and
reviewing results of any recent well intervention projects. This will also include updating Kuparuk geologic model.
Sincerely,
Joleen Oshiro
Reservoir Engineer - Northstar
