Any person, owner or operator, who proposes to drill a well for the production of geothermal resources or to drill an injection well shall first apply to the Division in accordance with Title 73, Chapter 3. Applications to appropriate water for geothermal purposes will be processed and investigated by the Division, and if they meet the requirements of Section 73-3-8, they will be approved by the State Engineer on a well-to-well basis or as a group of wells which comprise an operating unit and have like characteristics.
Appropriation of water for geothermal purposes shall not be considered mutually interchangeable with water for any other purpose. Water, brine, steam or condensate produced during a geothermal operation may be subject to further appropriation if physical conditions permit.
Before drilling an exploratory, production well, or injection well, the applicant shall submit a plan of operations to the State Engineer for his approval. The plan shall include:
If the owner or operator plans to deepen, redrill, plug, or perform any operation that will in any manner modify the well, an application shall be filed with the Division and written approval must be received prior to beginning work; however, in an emergency, the owner or operator may take action to prevent damage without receiving prior written approval from the Division, but in those cases the owner or operator shall report his action to the Division as soon as possible.
If the owner or operator plans to convert an existing geothermal well into an injection well with no change of mechanical condition, written request shall be filed with the Division and written approval must be received prior to beginning injection.
No changes in the point of diversion, place or nature of use shall be allowed until an amendment to the application is approved by the State Engineer in accordance with Section 73-3-3.
Notice of applications, permits, orders, or other actions received or issued by the Division may be given to any other agency or entity which may have information, comments, or interest in the activity involved.
Where the surface of the parcel of land is unavailable for drilling, the surface well location may be located upon property which may or may not be contiguous. Surface well locations shall not be less than 25 feet from the outer boundary of the parcel on which it is located, nor less than 25 feet from an existing street or road. The production or injection interval of the well shall not be less than 100 feet from the outer boundary of the parcel into which it is drilled.
Directional surveys must be filed with the Division for all wells directionally drilled.
The well number shall be according to the modified Kettleman Well Numbering System adopted by the U.S. Geological Survey.
All wells shall be cased in a manner to protect or minimize damage to the environment, usable ground waters and surface 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.
Specifications for casing strings shall be determined or approved on a well-to-well basis. All casing strings reaching the surface shall provide adequate anchorage for blowout-prevention equipment, hole pressure control and protection for all natural resources. The casing requirements given are general but should be used as guidelines in submitting proposals to drill (Plan of Operations).
A minimum of 40 feet of conductor casing shall be installed. The annular space is to be cemented solid to the surface. A 24-hour cure period for the grout must be allowed prior to drilling out the shoe unless additives approved by the State Engineer are used to obtain early strength. An annular blowout preventer shall be installed on all exploratory wells and on development wells when deemed necessary by the Division. For low-temperature geothermal wells less than 90 degrees C. this requirement may be reduced or waived by the State Engineer.
Except in the case of low-temperature geothermal wells, the surface casing hole shall be logged with an induction electrical log, or equivalent, before running casing or by gamma-neutron log. This requirement may vary from area to area, depending upon the amount of pre-existing subsurface geological data available. If sufficient subsurface geologic data is available, the State Engineer may not require additional logging of the surface casing hole. However, permission to omit this requirement must be granted by the Division prior to running surface casing.
Surface casing shall provide for control of formation fluids, for protection of shallow usable ground water and for adequate anchorage for blowout-prevention equipment. All surface casing shall be cemented solid to the surface. A 24-hour cure period shall be allowed prior to drilling out the shoe of the surface casing unless additives approved by the State Engineer are used to obtain early strength.
The temperature of the return mud shall be monitored regularly during the drilling of the surface casing hole. Either a continuous temperature monitoring device shall be installed and maintained in working condition, or the temperature shall be read manually. In either case, return mud temperature shall be logged after each joint of pipe has been drilled down 30 feet.
BOPE capable of shutting-in the well during any operation shall be installed on the surface casing and maintained ready for use at all times. BOPE pressure tests shall be witnessed by Division personnel on all exploratory wells prior to drilling out the shoe of the surface casing. The decision to require and witness BOPE pressure tests on all other wells shall be made on a well-to-well basis. The Division must be contacted 24 hours in advance of a scheduled pressure test. The State Engineer may give verbal permission to proceed with the test upon request by the operator.
Intermediate casing shall be required for protection against unusual pressure zones, cave-ins, wash-outs, abnormal temperature zones, uncontrollable lost circulation zones or other drilling hazards. Intermediate casing strings shall be cemented solid to the surface or to the top of the liner hanger whenever the intermediate casing string is run as a liner. The liner lap shall be pressure tested prior to resumption of drilling.
Production casing may be set above or through the producing or injection zone and cemented above the injection 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 zones that contain usable ground water. Production casing shall either be cemented solid to the surface or lapped into intermediate casing, if run. If the production casing is lapped into an intermediate casing, the casing overlap shall be at least 100 feet, the lap shall be cemented solid, and it shall be pressure tested to ensure its integrity.
All wells, except observation wells for monitoring purposes only, shall be logged with an induction electrical log or equivalent or gamma-neutron log from the bottom of the hole to the bottom of the conductor pipe. This requirement may be modified or waived by the Division upon written request if such request demonstrates sufficient existing data of surrounding wells.
Cements used in cementing casing and sealing formations must be of a grade and type best suited for expected reservoir temperature, formation water chemistry and bonding properties. Cements acceptable for use in high-temperature holes include Modified Type A or G, Alumina Silica Flour, Phosphate Bonded Glass, or other equivalent high-temperature design cement as approved by the Division.
Utah Admin. Code R655-1-2