Use of Induced Seismicity Screening Worksheet in Evaluating Proposals for Geothermal Well Stimulation Projects or Enhanced/Engineered Geothermal System (EGS) Operations
United States Department of the Interior
BUREAU OF LAND MANAGEMENT
Washington, D.C. 20240
https://www.blm.gov
September 20, 2018
In Reply Refer To:
3200(301)P
Instruction Memorandum No. 2018-107
Expires: 09/30/2021
To: State Directors
From: Assistant Director, Energy, Minerals, and Realty Management
Subject: Use of Induced Seismicity Screening Worksheet in Evaluating Proposals for Geothermal Well Stimulation Projects or Enhanced/Engineered Geothermal System (EGS) Operations
Program Area: Geothermal Resources Operations.
Purpose: This Instruction Memorandum (IM) and its attachments provide guidance for field office (FO) personnel who are evaluating proposals for geothermal activities that involve Enhanced/Engineered Geothermal System (EGS) operations or other well stimulation activities. It establishes procedures for the initial screening of any geothermal authorization request where the activity has the potential to create unintended seismic activity that may result in impacts to other resources. The screening tool allows BLM Field Office (FO) personnel to identify those low-risk projects that may proceed in the permitting process without the need for further probabilistic seismic risk analysis.
Administrative or Mission Related: This IM is mission related.
Policy/Action: This IM and attached guidance supports Administration priorities in accordance with Executive Order 13783, Promoting Energy Independence and Economic Growth, (March 28, 2017), and Secretarial Order (SO) 3349, American Energy Independence (March 29, 2017), by providing a consistent screening process for proposed geothermal well stimulation projects with the potential to cause induced seismicity.
These policies and procedures apply to processing Geothermal Drilling Permit (GDP), Utilization Plan, and sundry notice applications proposing EGS operations or well stimulation techniques for existing or new geothermal wells; these policies are consistent with existing authorities, including standard lease terms and the regulations for geothermal resource leasing at 43 CFR Part 3200 (see 43 CFR 3200.4; 43 CFR 3261.13; 43 CFR 3261.22; 43 CFR 3262.11; 43 CFR 3264.10; 43 CFR 3272.11and 43 CFR 3272.12), as well as Geothermal Resources Operational Order #4, “General Environmental Protection Requirements” (1975).
EGS is a term that describes a range of geothermal “stimulation” techniques (fluid injection) to create or improve permeability for fluid flow in geothermal resource reservoirs in rock formations where temperatures are high but little to no water is present, or the rock is not permeable enough for water to carry the heat energy to the surface at a sufficient flow rate to support production. Because implementation of EGS and other well stimulation operations affect subsurface conditions, especially the behavior of fractures, the potential to contribute to or increase the frequency or magnitude of seismic activity exists.
Application processing for geothermal well stimulation operations beyond routine maintenance cleanouts, or rates of injection that are within normal ranges for plant operations, will require use of the Induced Seismicity Screening Worksheet (ISS Worksheet) (Attachment 1). The ISS Worksheet will help determine if the proposed project includes sufficient information for the BLM to evaluate the potential for induced seismicity impacts or concerns, and to determine whether the BLM personnel have an appropriate level of technical expertise to process the permit. It should be noted that the worksheet is not intended to provide an analysis of the seismic risk or seismic hazard of any stimulation or EGS project, nor does successful completion of the screening factors guarantee approval of a permit.
Responses to the ISS Worksheet questions are to be documented on the ISS Worksheet Record (Attachment 2) and included in the official well file. Detailed instructions for completion of the worksheet and background information to explain the context and implications of each question are included in the ISS Worksheet Guidance Document (Attachment 3). The worksheet questions concern four subject matter areas. The first is intended to identify routine operations or maintenance activities that do not rise to any level of concern for IS, and whose applications can be processed without the need for further induced seismicity screening. The circumstance of inadequate data is also addressed in the first section. The other question areas are related to the operator’s record of compliance and plans for mitigation and public outreach; quantitative details of the proposed stimulation in terms of total volume, rates, and pressures of injection; details of the local geologic setting and background levels of seismicity; and proximity factors—to geologic faults as well as to populations centers and sensitive sites or facilities.
Results of the ISS Worksheet will fall into one of four categories: a zero-to-minimal level of concern (so low that further completion of the worksheet is not necessary; to screen out routine maintenance activities); low-level, medium-level, or high-level of concern for potential seismic impacts. If upon completion of the worksheet, no triggers for risk concerns have been tripped via “no” responses to any worksheet question (i.e., “induced seismicity (IS) screening passed”), the project is classified as presenting a low level of concern, and additional seismic risk analysis is not required. If the results show a medium level of concern for IS potential, the BLM State Office Geothermal Program Lead (SO Lead) must be consulted, who may work with appropriate seismic experts to identify any additional analyses that may be necessary, and/or inclusion of a monitoring and mitigation plan. A project with a high level of concern (usually due to sensitive or critical facilities located in close proximity to the project area) requires further processing of the application to be halted until consultation with the State Office Program Lead is conducted. The SO lead will, in turn, coordinate with seismic experts and may recommend that the Department of Energy’s (DOE) Induced Seismicity Protocol (2012) (See Attachment 3 for citation and details) process be implemented. This IM is not intended to provide guidance for or implementation of the full DOE IS Protocol.
Implementation Timeframe: This policy is effective immediately and applies to permit processing for all current and future GDP, Utilization Plan, and Sundry Notice applications involving geothermal well stimulation, EGS operations, or other activities that could result in induced seismicity impacts.
Budget Impact: This policy may produce additional revenue from increased geothermal production.
Background: The ISS Worksheet and guidance document were prepared by the National Renewable Energy Laboratory (NREL) in collaboration with a team of induced seismicity expert consultants (comprised of scientists from NREL, Lawrence Berkeley National Laboratory, USGS Earthquake Science Center), the Solicitor’s Office, and BLM subject matter experts. These screening tools are science-based but were designed to be used by BLM field office personnel without specific training in seismology or earthquake science, to identify those low-risk projects whose applications can also be processed within the BLM without the need for expert analysis of seismic hazards.
Manual/Handbook Sections Affected: None.
Coordination: This policy was coordinated with the Department of the Interior Office of the Solicitor (DMR), the BLM state and field offices, and the BLM Energy, Minerals, and Realty Management Directorate.
Contact: If there are any questions concerning this IM, please contact me at 202-208-4201. For program questions, your staff may contact Dan Munger, National Geothermal Program Lead (Acting) at dmunger@blm.gov, Lorenzo Trimble, National Geothermal Program Lead at 202-912-7342 (ltrimble@blm.gov), or the Renewable Energy Coordination Office (WO-301) at 208-613-8958.
Signed by:
Michael D. Nedd
Assistant Director,
Energy, Minerals, and Realty Management Directorate
Authenticated by:
Catherine Emmett
WO-870, IT Policy and Planning
3 Attachments
1 – Induced Seismicity Screening Worksheet (1 p)
2 – Induced Seismicity Screening Worksheet Record (1 p)
3 – Induced Seismicity Screening Worksheet Guidance Document (17 pp)