Hilcorp Alaska LLC

BP Liberty Map


The Liberty Prospect is located 8.85 km offshore in about 6m of water, inside the Beaufort Sea's barrier islands. It is 32 km east of Prudhoe Bay and about 13 km east of the existing BP-operated Endicott oil field.

In November 2014, primary ownership and operatorship of Liberty was acquired by Hilcorp. Hilcorp estimates that the Liberty Unit contains approximately 150 million barrels of recoverable, high-quality crude oil.






Apr 21

BSEE notifies Hilcorp of the addition of Lease OCS-Y-01886 to the Liberty Unit.

Apr 06

Hilcorp responds to BSEE communication regarding unitization matters. Hilcorp, as operator of the Liberty Unit, requests that BSEE approve the expansion of the Liberty Unit to include oil and gas lease OCS-Y-01886.

Mar 28

Liberty Prospect EIS extended comment period closes.

Mar 04

Hilcorp submits reports in response to BOEM's request for copies of documents mentioned in the Liberty DPP.

Jan 26

BOEM extends comment period on Liberty Prospect EIS. BOEM grants this extension to support the intent of the National Environmental Policy Act (NEPA), to collect information to define the scope of issues to be addressed in depth in the analyses that will be included in the EIS, and to provide an additional opportunity for interested and affected parties to comment. Further details are available in the Note to Stakeholders.

Jan 20

Hilcorp Alaska requests a 60-day extension of the Liberty EIS scoping period.


Nov 30

BOEM publishes in the Federal Register a notice officially extending the Liberty EIS comment period to Jan. 26, 2016, per the Nov. 17 announcement below. Regulations.gov comment docket (NOTE: now closed).

Nov 17

In response to requests from the public, BOEM extends for an additional 60 days the comment period associated with the Notice of Intent (NOI) to Prepare an Environmental Impact Statement (EIS) for the Liberty Development and Production Plan (DPP) in the Beaufort Sea Planning Area. 

As part of its regulatory program, BOEM on Sept. 25, 2015 issued a Notice of Intent to prepare an Environmental Impact Statement (EIS). This EIS will analyze the DPP’s potential environmental effects, and will provide opportunity for public comment. BOEM will not make a decision to approve, disapprove, or require modifications to the DPP until after the completion of the EIS.

The original 60-day comment period was to end Nov. 24, 2015. With this 60-day extension, the comment period will now end Jan. 26, 2016, giving the public additional time to provide input.

For more information on this topic, see the item dated Sept. 25, 2015 (below).

Nov 17

The Sept. 18 - Nov. 17 public comment period on the DPP closes (see Sept. 18 item, below).

Note that this comment period is separate and distinct from the comment period on the EIS, which is described in the entry under Sept. 25. The EIS comment period will remain open until Jan. 26, 2016.

Sep 25

BOEM publishes in the Federal Register a Notice of Intent to Prepare an Environmental Impact Statement (EIS) to analyze the potential environmental effects of the DPP received from Hilcorp, Alaska LLC on Sept. 18, 2015.

The publication of the Notice in the Federal Register opens a 60-day public comment period ending at midnight Eastern Time on Tuesday, Nov. 24, 2015 [EDIT - On Nov. 17, 2015, BOEM announced that this comment period would be extended to Jan. 26, 2016]. During this time, BOEM will hold public scoping meetings in Alaska and accept comments through www.regulations.gov

SCHEDULE FOR SCOPING MEETINGS (all meetings 7 p.m. to 10 p.m.)

Nov. 2: FAIRBANKS (Westmark Conference Center)
Nov. 3: KAKTOVIK (Kaktovik Community Center)
Nov. 4: NUIQSUT (Kisik Community Center)
Nov. 5: BARROW (Iñupiat Heritage Center)
Nov. 9: ANCHORAGE (Embassy Suites, Benson Blvd)

Note that this comment period on the EIS is separate and distinct from the Sept. 18 - Nov. 17 comment period on the DPP itself, as described in the entry for Sept. 18, below.

Sep 18 BOEM deems submitted a Development and Production Plan (DPP) received from Hilcorp Alaska, LLC relating to oil and gas development on the Liberty Prospect. The plan will now move forward through the government’s review process.

This initiates a 60-day period for the public to review and comment on the DPP. Comments may be submitted (and comments left by others may be viewed) through www.regulations.gov (direct link). Comments must be received by midnight Eastern Time on Nov. 17, 2015.

As part of its regulatory program, BOEM will on Sept. 25, 2015 announce a Notice of Intent to prepare an Environmental Impact Statement (EIS). This EIS will analyze the DPP’s potential environmental effects, and will provide opportunity for public comment. It is anticipated that the environmental analysis of the DPP will take several years and will be closely coordinated with numerous federal and state agencies and consultations with appropriate federally recognized tribes.

Feb 04

Upon completing a preliminary review, BOEM determines that the Development and Production Plan (DPP) received from Hilcorp on Dec. 30, 2014 does not contain sufficient information to fully address one or more of the data requirements listed under 30 CFR 550.242, and requests additional information from Hilcorp.


Dec 30

BOEM's Alaska OCS Region receives from Hilcorp Alaska LLC a Development and Production Plan (DPP) for the Liberty Prospect. In the DPP, Hilcorp proposes to build a drilling and processing facility on a man-made gravel island about 9 km offshore. In this respect, the plan is similar to the company’s Northstar Facility, located about 50 km to the northwest, which began production in October 2001. Having received the DPP, BOEM now has 25 working days to conduct a preliminary review to assess whether it includes all the required components. By the end of that period BOEM must either formally deem the DPP submitted, which triggers further regulatory review and a review under the National Environmental Policy Act; or let Hilcorp know what additional information would be required in order to deem the DPP submitted. BOEM will notify the public in the near future regarding public comment opportunities relating to the Liberty DPP.

Nov 18

Hilcorp Alaska takes over and accepts the duties and responsibilities of Operatorship of the Northstar and Liberty units. Letter to BOEM.

Jul 24

BOEM Alaska Region's response to BPXA letter dated May 7, 2014, requesting that BOEM AKR withdraw BP Exploration (Alaska) Inc.'s (BPXA) 2008 Development and Production Plan (DPP) for the Liberty unit leases OCS Y -1585 and Y -1650.

May 07

BPXA request that the 2008 Liberty Development and Production Plan (DPP) be withdrawn. The Liberty ultra-extended reach (uERD) project that was submitted to the Mineral Management Service (MMS) on April 25th , 2007 and formally approved by MMS on January 3rd, 2008. The 2008 DPP approval was for drilling and producing of up to six development wells from an expansion of the Endicott Satellite Drilling Island to bottom-hole locations in the OCS.

Apr 28

BOEM letter regarding BP Exploration (Alaska) Response to Notice to Conduct Ancillary Activities for leases OCS Y-1585 and OCSY-1650.

Apr 22

BP announces that it has agreed to sell interests in four BP-operated oilfields on the North Slope of Alaska to Hilcorp Alaska, LLC (Hilcorp Alaska). The sale agreement includes all of BP’s interests in the Endicott and Northstar oilfields and a 50-percent interest in each of the Liberty and the Milne Point fields. The sale also includes BP’s interests in the oil and gas pipelines associated with these fields.


Dec 31

BSEE letter responding to BPXA Request for Suspension of Production and revised Plan of Operation for leases OCS Y-1585 and OCSY-1650.

Nov 20

BPXA submits a Request for Suspension of Production (SOP) & Revised Plan of Operations for their Liberty Unit in accordance with 43 U.S.C. 1332(3), 30 CFR 250.174(a) and 30 CFR 256.73(c). BPXA requests that the Bureau of Safety and Environmental Enforcement (BSEE) grant a five-year SOP for leases OCS Y-1585 and Y-1650 to support the most efficient and expeditious option available for development of the Liberty Prospect.

Mar 02

U.S. Fish and Wildlife Service letter regarding the revised raven nest and fox den monitoring plan for Liberty Development.


Mar 02


Dec 16

BP Exploration (Alaska) letter regarding the 2010 Liberty SDI Raven Nesting Monitoring Report.

Apr 21

BP Exploration (Alaska) letter regarding the geomagnetic observations in support of the planned Liberty Ultra Extended Reach Drilling well.


Jul 20

BP Exploration (Alaska) letter regarding the Notification of Signed Conflict Avoidance Agreement2009Sealift Activities Liberty Development.

Jun 15

BP Exploration (Alaska) letter regarding the Development and Production Plan Approval Condition #4 Liberty Development.

Mar 13

BP Exploration (Alaska) letter regarding Liberty Project Endangered Species Act Section 7 Consultation.


Jan 03

MMS approves the DPP in accordance with 30 CFR 250.280. BPXA must conduct all lease activities in compliance with the approved DPP.


Apr 25

BPXA submits Liberty Development and Production Plan to MMS. After studying a number of alternative development options, BPXA proposes to develop the Liberty Prospect by means of an onshore development using leading edge, ultra-extended reach drilling. This plan proposes drilling and producing up to six development wells from a planned expansion of the existing Endicott Satellite Drilling Island (SDI) to bottom-hole locations under OCS lease 1650.



MMS publishes Liberty Development and Production Plan Final Environmental Impact Statement (OCS EIS/EA MMS 2002-020). This Environmental Impact Statement (EIS) covers the proposed Beaufort Sea Oil and Gas Development/Liberty Development and Production Plan. This document includes the purpose and background of the proposed action, alternatives, description of the affected environment, and the estimated environmental effects of the proposed action and the alternatives. The alternative analysis evaluates five sets of component alternatives (island location and pipeline route, pipeline design, upper slope-protection system, gravel mine site, and pipeline burial depth) that focus on the different effects of modifying major project elements. The EIS also evaluates the range of alternatives that could be chosen by combining different options from the component alternatives. In addition to the mitigation MMS requires in the lease and those built into BPXA’s Proposal, the EIS evaluates two proposed mitigating measures and their potential effects. The EIS also evaluates potential cumulative effects resulting from the BPXA Proposal and alternatives. The EIS also describes and analyzes the potential effects of the MMS’s Agency-Preferred Alternative and the Environmental Protection Agency’s Agency-Preferred Alternative.


BPXA publicly announces they are putting the Liberty Project on hold pending re-evaluation of project configuration and costs. MMS publishes and files the final environmental impact statement (EIS) for the Liberty DPP with the Environmental Protection Agency (EPA), because MMS expects this final EIS will serve as a reference document for future projects.


Dec 31

The National Marine Fisheries Service (NFMS) issues a biological opinion (BO) on the proposed Liberty project and its effects on the bowhead whale in accordance with section 7 of the Endangered Species Act of 1973. Through informal consultation, NMFS agencies determined that bowhead whales are the only listed species for which NMFS bears responsibility that would be adversely affected by this work. No designated critical habitat occurs in the area that would be affected by the proposed Liberty project. After reviewing the relevant information available on the biology and ecology of bowhead whales in the action area and the direct and indirect effects of the proposed Liberty project, NMFS concludes that the proposed project is not likely to jeopardize the continued existence of the bowhead whale.


1982 - 2000
Jul 2000

DPP Revision 2.

Nov 1998

DPP Revision 1.

Mar 1998

BPXA submits a pipeline Right-of-Way application.

Feb 1998

BPXA submits a Development and Production Plan to MMS for the proposed Liberty Project.

May 1997

Based on interpretation of geologic interpretation, seismic data, and well tests, BPXA confirms the discovery of an estimated 120 million barrels of recoverable reserves from the Liberty prospect.

Apr 1997

Liberty #1 Exploration Well drilling operation demobilized.

Mar 1998

BPXA submits a pipeline Right-of-Way application.

Feb 1997

Drilling of the Liberty # 1 well begins, followed by well testing in March 1997.

Sep 1996

BP Exploration (Alaska) Inc. (BPXA) acquires OCS lease 1650 (OCS-Y-1650) in Minerals Management Service (MMS) OCS Lease Sale 144; and initiates permitting activity for the Liberty #1 Exploration Well.

1982 - 1987

Shell Oil Company drills four wells to evaluate the potential of marketable oil reserves at the Liberty Prospect. Three of the wells are drilled from Tern Island, which Shell constructed in 1981-1982. The fourth well is drilled from Goose Island, located southeast of Tern Island.