Idaho Administrative Code
Title IDAPA 37 - Water Resources, Department of
Rule 37.03.04 - DRILLING FOR GEOTHERMAL RESOURCES RULES
Section 37.03.04.025 - DRILLING

a. Permit to Drill for Geothermal Resources. Any person, owner, or operator who proposes to construct or alter a well to produce or explore for geothermal resources or to construct or alter an injection well shall first apply to the Director for permit. If the owner or operator plans to deepen, redrill, plug, or perform any operation that will in any manner alter the well, an application shall be filed with the Director and written approval must be received prior to beginning work. Application for permit shall be on a form approved by the Department. (3-30-23)

b. Application for Permit to Convert to Injection. If the owner plans to convert an existing geothermal well into an injection well with no change of mechanical condition, an application for permit shall be filed with the Director and written approval must be received prior to beginning injection. Application for permit shall be made on a form approved by the Department. (3-30-23)

c. Amendment of Permit. No well may be owned or operated by any person whose name does not appear on the permit or permit application and no changes in departure from the procedures, location, data, or persons specified on the face of a permit shall be allowed until an amendment to such permit is approved by the Director. Application for amendment shall be made on a form approved by the Department. (3-30-23)

d. Notice to Other Agencies. Notice of applications, permits, orders, or other actions received or issued by the Director may be given to any other agency or entity which may have information, comments, or jurisdiction over the activity involved. The Director may execute a memorandum of understanding with other agencies to eliminate duplication of applications or other efforts. (3-30-23)

e. No application shall be accepted by the Director until the filing fee required by § 42-4003(5), Idaho Code has been deposited with the Director. (3-30-23)

a. The Director shall require every operator or owner who engages in the construction, alteration, testing, operation, or abandonment of the well to provide to the Director evidence of good and sufficient security in the form and amounts required by Idaho Code § 42-4005(f). (3-30-23)

b. Bonds remain in force for the life of the well or wells and may not be released until the well or wells are properly abandoned, or another valid bond is substituted therefor. Any person who acquires the ownership or operation of any well or wells shall within thirty (30) days after acquisition provide to the Director evidence of good and sufficient security in the form and amounts required by Idaho Code § 42-4005(f). (3-30-23)

a. Any well drilled for the discovery and production of geothermal resources or as an injection well shall be located more than one hundred (100) feet from and within the outer boundary of the parcel of land on which the well is situated, or more than one hundred (100) feet from a public road, street, or highway dedicated prior to the commencement of drilling. This requirement may be modified or waived by the Director upon written request. (3-30-23)

b. For several contiguous parcels of land in one or different ownerships that are operated as a single geothermal field, the term outer boundary line means the outer boundary line of the land included in the field. In determining the contiguity of any such parcels of land, no street, road, or alley lying within the lease or field shall be determined to interrupt such contiguity. (3-30-23)

c. The Director shall approve the proposed well spacing programs or prescribe such modifications to the programs as he deems necessary for proper development giving consideration to such factors as, but not limited to, topographic characteristics of the area, hydrologic, geologic, and reservoir characteristics of the area, the number of wells that can be economically drilled to provide the necessary volume of geothermal resources for the intended use, minimizing well interference, unreasonable interference with multiple use of lands, and protection of the environment. (3-30-23)

d. Directional Drilling. Where the surface of the parcel of land containing one acre or more is unavailable for drilling, the surface well location may be located upon property which may or may not be contiguous. Such surface well locations shall not be less than twenty-five (25) feet from the outer boundary of the parcel on which it is located, nor less than twenty-five (25) feet from an existing street or road. The production or injection interval of the well shall not be less than one hundred (100) feet from the outer boundary of the parcel into which it is drilled. Directional surveys must be filed with the Director for all wells directionally drilled. (3-30-23)

a. General. All wells shall be cased in such a manner as to protect or minimize damage to the environment, usable ground waters, geothermal resources, life, health, and property. The permanent well head completion equipment shall be attached to the production casing or to the intermediate casing if production casing does not reach the surface. No permanent well head equipment may be attached to any conductor or surface casing alone. The specification for casing strength shall be determined by the Director on a well-to-well basis. All casing reaching the surface shall provide adequate anchorage for blow out prevention equipment, hole pressure control, and protection for natural resources. Sufficient casing shall be run to reach a depth below all known or reasonably estimated groundwater levels to prevent blow outs or uncontrolled flows. The following casing requirements are general but should be used as guidelines in submitting applications for permit to drill. The casing schedule may consist of multiple casing strings (i.e., surface casing, intermediate casing, production casing) provided drilling depth does not exceed ten times the depth of last cemented casing. (3-30-23)

b. Conductor Pipe. A minimum of forty (40) feet of conductor pipe shall be installed. The annular space is to be cemented solid to the surface. A twenty-four (24) hour cure period for the grout must be allowed prior to drilling out the shoe unless additives sufficient, as determined by the Director, are used to obtain early strength. An annular blow out preventer shall be installed on all exploratory wells and on development wells when deemed necessary by the Department. (3-30-23)

c. Surface Casing. The surface casing hole shall be logged with an induction electrical log or equivalent or gamma-neutron log before running casing. This requirement may be waived by the Director. Permission to waive this requirement must be granted by the Director in writing prior to running surface casing. This casing shall provide for control of formation fluids, protection of usable groundwater, and for adequate anchorage for blow out prevention equipment. All surface casing shall be cemented solid to the surface. A twenty-four (24) hour cure period shall be allowed prior to drilling out the shoe of the surface casing unless additives sufficient, as determined by the Director, are used to obtain early strength. (3-30-23)

d. Intermediate Casing. Intermediate casing shall be required for protection against anomalous pressure zones, cave-ins, washouts, abnormal temperature zones, uncontrollable lost circulation zones or other drilling hazards. Intermediate casing strings when installed shall be cemented solidly to the surface or to the top of the casing. (3-30-23)

e. Production Casing. Production casing may be set above or through the producing or injection zone and cemented either below or just above the objective zones. Sufficient cement shall be used to exclude overlying formation fluids from the geothermal zone, to segregate zones, and to prevent movement of fluids behind the casing into possible fresh groundwater zones. Production casing shall either be cemented solid to the surface or lapped into the intermediate casing if run. If the production casing is lapped into an intermediate casing, the casing overlap shall be at least fifty (50) feet, the lap shall be cemented solid, and the lap shall be pressure tested to ensure its integrity. (3-30-23)