Department of Commerce, Community, and Economic Development
Alaska Oil and Gas Conservation Commission
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HomeMy WebLinkAbout2024 Endicott Oil Pool
Hilcorp Alaska, LLC
Post Office Box 244027
Anchorage, AK 99524-4027
3800 Centerpoint Drive
Suite 1400
Anchorage, AK 99503
Phone: 907/564-5246
Gavin.Dittman@hilcorp.com
April 1st, 2025
Brett Huber Sr, Chair
Alaska Oil & Gas Conservation Commission
333 W. 7th Avenue, Suite 100
Anchorage, Alaska 99501-3539
RE: DUCK ISLAND UNIT, ENDICOTT FIELD, ENDICOTT OIL POOL, STATE OF ALASKA,
2024 ANNUAL RESERVOIR REVIEW
Dear Commissioner Huber:
In accordance with Conservation Order No. 462, Hilcorp Alaska, LLC (“Hilcorp”), as Operator, hereby submits for
your review the following Annual Reservoir Review for the Endicott Field.
This is the Annual Reservoir Review and corresponds to events during the 2024 calendar year. The Endicott Field
has been on production since October 1987.
A. Progress of Enhanced Recovery Project and Reservoir Management Summary
During 2024, two new wells were drilled in the Duck Island Unit in the Eider Oil Pool. The locations of all other wells
in the Duck Island Unit remain unchanged.
Production and injection statistics are summarized in Table 1. Average daily oil production from the Endicott Oil
Pool was 4593 bopd and average daily gas injection was 318 mmscfpd.
During 2024, injected fluid was calculated to be 9158 thousand-reservoir barrels (MRB) less than reservoir voidage.
At year end, the reservoir overall cumulative voidage replacement ratio was 0.84. The average reservoir pressure
varies between zones. The average of surveys run in 2024 was 3874 psia.
Hilcorp became the official operator of the Endicott Field effective November 18, 2014. Hilcorp will continue to
identify and improve waterflood pattern efficiency by allocating existing water injection volumes and adding
perforations in active injection wells. Hilcorp is currently reviewing debottlenecking projects at Endicott to boost
gas and water handling capacities. The field is continuing to evaluate options to reduce H2S production rates in
producers.
Page 2
As of 12/31/2024 Full year (1) As of Dec-24 (2)
Producers 58 52
Injectors 28 28
2024
Cumulative Start-
Up through
12/31/23
1,681,072 489,351,649
128,604,670 4,301,595,635
76,393,089 2,399,653,536
76,924,849 2,331,596,879
116,470,360 3,720,829,540
165,666,794 5,745,923,685
156,509,046 4,874,039,704
-9,157,748 -871,883,981
4,593
351,379
208,724
210,177
318,225
3,874 psiaAverage of surveys obtained in 2024
Water, BWPD
Injection
Water, BWPD
Gas, MCFPD
AVERAGE RESERVOIR PRESSURE
DAILY AVERAGE RATE DATA 2024
Production
Oil, BOPD
Gas, MCF/D
Gas (MCF)
Balance
Cum Production (MRB)
Cum Injection (MRB)
Over/Under (MRB)
Oil (BBL)
Gas (MCF)
Water (BBL)
Injection
Water (BBL)
(1) Well count data reflects ONLY those wells which contributed to production/injection during the respective year
(2) Active wells as of December 31 2024
PRODUCTION/INJECTION STATISTICS
Production
Table 1: ENDICOTT FIELD 2024 OVERVIEW STATISTICAL SUMMARY
WELL STATISTICS
NOTES:
Page 3
B. Voidage Balance by Month of Produced Fluid and Injected Fluids – 2024
C. Summary and Analysis of reservoir pressure surveys within the pool
The following key wells in the Endicott Pool were proposed in 2024:
2024 Key Well Program
2-62 S3A, F1, F3 2-38 Ivishak
1-19 K2B 2-56A Sag River - Eider
1-33B K2A
2-18 S3A, F1
Endicott Oil Pool Datum: -10,000 ssTVD
Eider Oil Pool Datum: -9,700 ssTVD
Static bottomhole pressures collected in 2024 are summarized and submitted on the form 10-412 form below.
The following key wells in the Endicott Pool will have static bottomhole pressure measurements captured in 2025;
Month Oil, RB Free Gas, RB
Water,
MRB
Total
Voidage,
MRB
Year
Cum, MRB
Cum since
start-up, MRB
Formation
Gas, MRB
Water,
MRB
Total
Injection,
MRB
Year
Cum, MRB
Cum since
start-up, MRB
Net
Injection,
MRB
Year
Cum, MRB
Cum since start-
up, MRB
Jan-2023 205,678 7,769,044 6,669,589 14,644,310 14,644,310 5,594,901,201 7,093,626 6,704,803 13,798,429 13,798,429 4,731,329,086 -845,882 -845,882 -863,572,114
Feb-2023 197,342 7,363,713 6,462,808 14,023,863 28,668,173 5,608,925,064 6,732,667 6,470,747 13,203,414 27,001,843 4,744,532,500 -820,449 -1,666,331 -864,392,563
Mar-2023 197,126 7,624,899 7,164,317 14,986,342 43,654,515 5,623,911,406 6,939,957 7,175,509 14,115,466 41,117,309 4,758,647,966 -870,876 -2,537,207 -865,263,440
Apr-2023 183,312 7,246,240 6,463,418 13,892,970 57,547,485 5,637,804,375 6,584,384 6,470,701 13,055,085 54,172,394 4,771,703,051 -837,885 -3,375,091 -866,101,324
May-2023 177,679 6,631,390 5,736,827 12,545,897 70,093,382 5,650,350,272 6,034,476 5,734,766 11,769,242 65,941,636 4,783,472,294 -776,654 -4,151,746 -866,877,978
Jun-2023 195,121 7,353,125 6,648,853 14,197,099 84,290,480 5,664,547,371 6,721,367 6,663,439 13,384,806 79,326,442 4,796,857,100 -812,293 -4,964,038 -867,690,271
Jul-2023 202,072 7,293,084 6,841,749 14,336,905 98,627,385 5,678,884,275 6,700,655 6,841,051 13,541,706 92,868,148 4,810,398,806 -795,199 -5,759,237 -868,485,470
Aug-2023 181,969 6,739,185 6,178,579 13,099,733 111,727,118 5,691,984,008 6,163,803 6,179,816 12,343,619 105,211,767 4,822,742,425 -756,114 -6,515,351 -869,241,584
Sep-2023 150,368 5,861,825 4,729,110 10,741,303 122,468,421 5,702,725,311 5,350,350 4,867,679 10,218,029 115,429,796 4,832,960,453 -523,274 -7,038,625 -869,764,858
Oct-2023 187,816 7,786,052 6,483,474 14,457,342 136,925,763 5,717,182,654 7,223,447 6,661,597 13,885,044 129,314,840 4,846,845,497 -572,298 -7,610,923 -870,337,156
Nov-2023 190,125 7,581,138 6,307,205 14,078,468 151,004,231 5,731,261,122 6,953,427 6,388,278 13,341,705 142,656,545 4,860,187,202 -736,763 -8,347,687 -871,073,920
Dec-2023 202,522 7,752,881 6,707,160 14,662,563 165,666,794 5,745,923,685 7,086,038 6,766,463 13,852,501 156,509,046 4,874,039,704 -810,062 -9,157,748 -871,883,981
Produced Fluids Injected Fluids (Injection - Production)
6. Oil Gravity:
22
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
2-62 5008420008 O 220100 S3A, F1, F3
9920 - 9939,
9962 - 9985,
9989 - 9993,
10001 - 10009,
10014 - 10018,
10095 - 10105,
10128 - 10136,
10143 - 10195
6/24/2024 504 SBHP 206 10,000 4,137 10,000 0.41 4,137
1-19 5008420068 O 220100 K2B 9829 - 9835 5/25/2024 192 SBHP 204 9,800 3,642 10,000 0.09 3,659
1-33B 5008420069 O 220100 K2A 10016 - 10019 9/7/2024 216 SBHP 190 9,145 3,692 10,000 0.44 4,068
2-56A 5008420076 O 220165 Sag River 9434 - 9457,
9472 - 9506 5/28/2024 264 SBHP 188 9,400 1,359 9,700 0.36 1,467
2-18 5008420048 O 220100 S3A, F1
9920 - 9927,
9931 - 9937,
10007 - 10014,
10024 - 10031,
10076 - 10080,
10100 - 10105
6/1/2024 360 SBHP 190 9,275 3,294 10,000 0.09 3,359
2-38 5008420052 O 220150 Ivishak
9933 - 9957,
9982 - 9986,
9989 - 10068
5/25/2024 192 SBHP 208 10,000 4,222 10,000 0.43 4,222
2-72 5008420117 O 220165 Ivishak
10036 - 10051,
10070 - 10085,
10089 - 10115
11/16/2024 - SBHP 204 10,000 4,013 10,000 0.44 4,013
3-07A 5008420040 O 220100 K2B
9950 - 9958,
9973 - 9979,
9982 - 9993,
10015 - 10040
11/19/2024 19,752 SBHP 200 10,000 4,145 10,000 0.44 4,145
Comments:
Gavin Dittman
23. All tests reported herein were made in accordance w ith 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
Reservior Engineer
March 5, 2025
RESERVOIR PRESSURE REPORT
1. Operator: 2. Address:
Hilcorp Alaska, LLC 3800 Centerpoint Dr Suite 1400, Anchorage AK 99503
7. Gas Gravity:
Duck Island Unit/Endicott Endicott Field/Endicott Oil Pool -10000 .88
3. Unit or Lease Name: 4. Field and Pool: 5. Datum Reference:
Page 4
2024 Key Well Program
3-33A K2A 2-58 F5 & F6
1-25A K2A 1-35 S3A
2-38 Ivishak
1-03 K2B
Endicott Oil Pool Datum: -10,000 ssTVD
Eider Oil Pool Datum: -9,700 ssTVD
D. Summary and Analysis of Gas-Oil Contact or Gas Monitoring Surveillance Plan.
No gas monitoring logs were obtained in 2024.
A field wide current GOC is not likely to be identified as the Kekiktuk sands have several subzones that are
vertically separated and have different permeability. In addition, faulting in the reservoir may lead to hydraulic
isolation or partial pressure communication within a sub zone.
E. The Following Year Gas-Oil Contact or Gas Monitoring Surveillance Plan.
In 2025, we will run cased hole pulsed neutron logs as needed to monitor GOC and any potential remaining oil
zones following additional rig intervention/workover.
F. Results and Analysis of Production and Injection log surveys, tracer surveys, observation well surveys and
any other special monitoring
A production profile was obtained on producer 3-25B on 03/31/2024 which showed the bulk of the gas coming
from the upper K2A interval.
G. Future Development Plans & Review of Annual Plan of Operations and Development
In 2024, Hilcorp increased unit production through well intervention projects and other optimization
opportunities. The ongoing field studies of the Duck Island Unit will identify additional well intervention and
production enhancement opportunities.
Projects completed during the 2024 calendar year:
2-62 (Prod) – Endicott Oil Pool – USZ addperf
1-27 (Prod) – Endicott Oil Pool – K2B & S3A perf
2-54 (WINJ) – Endicott Oil Pool – Pulled HEX plug, restored injection into S3A
3-25B (Prod) – Endicott Oil Pool – Set patch over upper K2A for gas shutoff
2-16 (Prod) – Endicott Oil Pool – USZ addperf
2-72 (Prod) – Eider Oil Pool – New Ivishak producer
2-74 (Prod) – Eider Oil Pool – New Ivishak producer – collapsed liner
Projects planned for the 2025 calendar year:
In 2025, Hilcorp will pursue increased unit production through additional well intervention projects, any necessary
infrastructure and facility repairs, and other optimization opportunities as they arise. Slickline, e-line, coiled
Page 5
tubing, and other rigless interventions and planned throughout the year. Workover operations may be planned
for 2025 execution. No drill wells are planned at Endicott within the 2025 calendar year.
Hilcorp will continue to progress the Duck Island Unit field studies. This may include re-mapping potentially
productive horizons, updating well histories, reviewing all production and injection data, material balance
calculations, and reviewing results of recent well intervention projects.
Sincerely,
Gavin Dittman
Reservoir Engineer - Endicott
