Department of Commerce, Community, and Economic Development
Alaska Oil and Gas Conservation Commission
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HomeMy WebLinkAbout2019 Northstar Oil PoolHilcorp Alaska, LLC
Post Office Box 244027
Anchorage, AK 99524-4027
3800 Centerpoint Drive
Suite 1400
Anchorage, AK 99503
Phone: 907/777-8377
Fax: 907/777-8580
ckanyer@hilcorp.com
April 1st, 2020
Jeremy Price, Chair
Alaska Oil & Gas Conservation Commission
333 W. 7th Avenue, Suite 100
Anchorage, Alaska 99501-3539
RE: NORTHSTAR UNIT, NORTHSTAR FIELD, NORTHSTAR OIL POOL, STATE OF ALASKA,
2019 ANNUAL RESERVOIR REVIEW
Dear Commissioner Price:
In accordance with Conservation Order No. 458A, Hilcorp Alaska, LLC (“Hilcorp”), as Operator, hereby submits for
your review the following Annual Reservoir Review for the Northstar Field.
This is the 19th Annual Reservoir Review and corresponds to events during the 2019 calendar year. Note that the
Northstar Field has been on production since November 2001.
A.Progress of Enhanced Recovery Project and Reservoir Management Summary
During 2019, 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 and injection statistics are summarized in Table 1. Average daily oil production from the Northstar Oil
Pool was 5,680 bopd and average daily gas injection was 439.6 mmscfpd. The reservoir voidage balance values
reported do not include oil production or gas injection from outside the Northstar Oil Pool. The outside pool
production includes satellite well NS34A or Kuparuk zone production from wells NS-08, NS-13, NS-15, and NS-18.
Also Kuparuk production from NS-07 beginning April 2019. Kuparuk gas injection from wells NS-17 and NS-18
beginning in 2019 are also excluded.
During 2019, gas injection was calculated to be 102,198 thousand-reservoir barrels (MRB) more than reservoir
voidage. At year end, the reservoir overall cumulative voidage replacement ratio was 1.389. The average of
reservoir pressure control for 2019 was 5,417 psia.
Hilcorp became the official Operator of the Northstar Field effective November 18, 2014. As a result, the historic
reservoir simulation model developed by the previous operator will no longer will be utilized. Hilcorp continued to
focus efforts on the Kuparuk reservoir simulation model during 2019.
Page 2
B.Voidage Balance by Month of Produced Fluid and Injected Fluids – 2019
As of 12/31/2019 Full year (1)As of Dec-19 (2)
Producers 15 14
Injectors 8 7
2019
Cumulative Start-
Up through
12/31/19
2,073,134 174,286,838
124,151,653 2,621,970,441
2,185,656 69,541,831
2,185,656 74,819,485
160,460,304 2,964,350,237
770,712 1,801,537
872,909 1,902,264
102,198 100,728
5,680
340,142
5,988
5,988
439,617
5,417 psia
Table 1: NORTHSTAR FIELD 2019 OVERVIEW STATISTICAL SUMMARY
WELL STATISTICS
NOTES:
(1) Well count data reflects ONLY those wells which contributed to production/injection during the respective year
(2) Active wells as of December 2019
PRODUCTION/INJECTION STATISTICS
Production
Oil (BBL)
Gas (MCF)
Water (BBL)
Injection
Water (BBL) into NS10 & NS32 Disposal Well
Gas (MCF)
Balance (excludes satellite well NS-34A and NS08 & NS-18 Kup oil Production )
Cum Production (MRB)
Cum Injection (MRB)
Over/Under (MRB)
DAILY AVERAGE RATE DATA 2019
Production
Oil, BOPD
Gas, MCF/D
Average of surveys obtained in 2019
Water, BWPD
Injection
Water, BWPD
Gas, MCFPD
AVERAGE RESERVOIR PRESSURE
Month Oil, MRB Free Gas, MRB
Water,
MRB
Total
Voidage,
MRB
Year
Cum, MRB
Cum since
start-up, MRB
Formation
Gas,
MRB
Pilot/Purge
/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 481 8,086 244 8,567 8,567 8,567 8,405 3,164 11,569 11,569 11,569 3,002 3,002 3,002
Feb-2019 434 7,390 206 7,825 16,391 16,391 7,678 1,592 9,270 20,839 20,839 1,446 4,448 4,448
Mar-2019 455 7,767 229 8,223 24,614 24,614 8,069 1,975 10,044 30,883 30,883 1,821 6,269 6,269
Apr-2019 451 7,812 223 8,264 32,878 32,878 8,111 1,719 9,830 40,713 40,713 1,566 7,835 7,835
May-2019 383 6,418 198 6,801 39,679 39,679 6,672 2,617 9,289 50,001 50,001 2,488 10,323 10,323
Jun-2019 302 5,305 179 5,607 45,286 45,286 5,505 1,932 7,437 57,438 57,438 1,830 12,153 12,153
Jul-2019 342 6,222 185 6,564 51,850 51,850 6,449 2,239 8,688 66,126 66,126 2,124 14,277 14,277
Aug-2019 252 4,719 129 4,971 56,821 56,821 4,886 1,570 6,456 72,582 72,582 1,485 15,762 15,762
Sep-2019 346 6,195 162 6,541 63,362 63,362 6,424 2,102 8,526 81,109 81,109 1,986 17,747 17,747
Oct-2019 361 6,522 175 6,884 70,245 70,245 6,762 2,075 8,837 89,946 89,946 1,953 19,701 19,701
Nov-2019 386 7,006 180 7,391 77,637 77,637 7,261 1,865 9,126 99,072 99,072 1,735 21,435 21,435
Dec-2019 447 7,903 191 8,350 85,987 85,987 8,200 1,695 9,895 108,967 108,967 1,544 22,980 22,980
2019 Totals 4,641 81,346 2,301 85,987 84,423 24,544 108,967 22,980
Produced Fluids Injected Fluids
Net Injection
(Injection - Production)
Page 3
C.Summary and Analysis of reservoir pressure surveys within the pool
Static bottom hole pressures collected in 2019 are summarized below.
These pressures have been included with the historical Ivishak reservoir pressure data and are graphically
represented in the next figure.
6. Oil Gravity:
44/47
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-07 50029230810000 O 590150 Kuparuk 9,002' - 9,023'4/20/19 24.7 PBU 198.27 8,726 2,885 9,000 0.44 3,006
NS-07 50029230810000 O 590150 Kuparuk 9,002' - 9,023'4/26/19 4.1 PBU 191.2 8,726 2,814 9,000 0.09 2,839
NS-07 50029230810000 O 590150 Kuparuk 9,002' - 9,023'6/22/19 8.5 PBU 188.4 8,726 2,692 9,000 0.09 2,717
NS-07 50029230810000 O 590150 Kuparuk 9,002' - 9,023'8/30/19 186.6 PBU 188.4 8,726 2,707 9,000 0.09 2,731
NS-13 50029230680000 O 590150 Kuparuk 8,924'-8,961'6/21/19 117 PBU 179.6 8,485 2,504 9,000 0.09 2,550
NS-13 50029230680000 O 590150 Kuparuk 8,924'-8,961'8/30/19 186.9 PBU 179.6 8,485 2,511 9,000 0.09 2,557
NS-18 50029231020000 O 590150 Kuparuk 8,942'-9,038'1/17/19 330.6 SBHP 182.3 9,000 2,865 9,000 0.07 2,865
NS-06 50029230880000 O 590100 Ivishak 11,036'-11,155'3/21/19 448.2 SBHP 254.6 11,100 5,357 11,100 0.13 5,357
NS-07 50029230810000 O 590100 Ivishak 11,111'-11,125'3/19/19 53.4 SBHP 253.6 10,900 5,400 11,100 0.10 5,421
NS-14A 50029230260100 O 590100 Ivishak 11,089'-11,092'1/19/19 124.3 SBHP 252.7 11,000 5,430 11,100 0.10 5,440
NS-16A 50029230960100 O 590100 Ivishak 11.085'-11.146'12/29/19 151.9 SBHP 253.6 11,045 5,435 11,100 0.10 5,441
NS-19 50029230520000 O 590100 Ivishak 11,118'-11,140'1/20/19 6181.9 SBHP 251.6 10,900 5,319 11,100 0.10 5,339
NS-20 50029231180000 O 590100 Ivishak 10,957'-11,040'9/9/19 541 SBHP 250 10,966 5,403 11,100 0.10 5,417
NS-21 50029231260000 O 590100 Ivishak 10,999' - 11,067'9/10/19 255.5 SBHP 250.3 11,000 5,385 11,100 0.11 5,396
Comments:
Chris Kanyer
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
April 1, 2020
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/-9,000 0.75
3. Unit or Lease Name:5. Datum Reference:4. Field and Pool: Northstar Field/
Northstar Oil&Kuparuk Oil Pools
Page 4
The data shows an increase of reservoir pressure during 2019. The average Northstar field reservoir pressure for
2019 is 5,417 psia, up 89 psia from the 2018 average. Please note that the reported reservoir pressure of the well
NS-13, NS-18, and NS-07 (after April 2019) are from the Kuparuk Reservoir.
D.Results and Analysis of Production and Injection log surveys, tracer surveys, observation well
surveys and any other special monitoring
No new Ivishak production profiles were obtained in 2019.
The gas tracer program, initiated in 2004, was concluded in 2008 and there are no further updates for this reporting
period.
Page 5
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.
2019 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).
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 2019 averaged 1.32 for oil, 0.98 for water and 0.94 for gas. Oil allocation
factor was high due to allocation of NGL production. This data includes all Kuparuk producers as well.
Page 6
F. & G. Future Development Plans & Review of Annual Plan of Operations and Development
In 2019, Hilcorp continued to maintained unit production through optimization opportunities. The field study of
the Northstar Unit was continued. Well histories, production and injection data, material balance calculations,
geological, and geophysical work were studied and updated. The Ivishak reservoir simulation model, begun in
2015, was unrealistically matched to the historical Ivishak reservoir data. This project was deferred for work on
the Kuparuk reservoir model. The Ivishak model be revisited and refined for possible future development
purposes.
Projects completed during the 2019 calendar year:
·NS-07 - Performed RWO recompletion from the Ivishak reservoir producer to a Kuparuk C producer; (April
2019)
·NS-17 - Performed RWO recompletion from the Ivishak reservoir gas injector to a lean gas injection well in the
Kuparuk C reservoir. (October 2019)
·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)
o Began the necessary infrastructure, facility modifications and tie-ins for this project. (September 2019
and ongoing).
Projects planned for the 2020 calendar year:
In 2020, 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 2020 calendar year.
The mobilization of a workover rig to the Northstar Island during the 2020 is tentatively planned for the summer
barge season to run a shallow upper completion to add a SCSSSV (surface controlled subsurface safety valve) for
the current NS-25 Ivishak production well.
The Northstar Propane Chiller Project will continue into 2020 with the construction of an ice road, install support
frames, set chiller modules, and install associated chiller system piping. Plans are to commission the chiller during
summer 2020 for improved NGL recovery during warmer ambient temperatures.
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.
Sincerely,
Chris Kanyer
Reservoir Engineer - Northstar
