43 C.F.R. § 3280.2
The following terms, as used in this part or in any agreement approved under the regulations in this part, have the following meanings unless otherwise defined in such agreement:
Minimum initial unit obligation means the requirement to complete at least one unit well within the timeframe specified in the unit agreement. If this requirement is not met, BLM deems the unit void as though it was never in effect.
Participating area means that part of the unit area that BLM deems to be productive from a horizon or deposit, and to which production would be allocated in the manner described in the unit agreement, assuming that all lands are committed to the unit agreement.
Plan of development means the document a unit operator submits to BLM defining how the unit operator will diligently pursue unit exploration and development to meet both initial and subsequent unit development and public interest obligations.
Public interest means operations within a geothermal unit resulting in:
Reasonably proven to produce means a sufficient demonstration, based on scientific and technical information, that lands are contributing to unit production in commercial quantities or are providing reservoir pressure support for unit production.
Unit agreement means an agreement for the exploration, development, production, and utilization of separately owned interests in the geothermal resources made subject thereto as a single consolidated unit without regard to separate ownerships, which provides for the allocation of costs and benefits on a basis defined in the agreement or plan.
Unit area means the area described in a unit agreement as constituting the land logically subject to development under such agreement.
Unit contraction provision means a term of a unit agreement providing that the boundaries of the unit area will contract to the size of the participating area, by having those lands outside of the participating area removed. BLM will contract the unit area if additional unit wells are not drilled and completed within the timeframe specified in the unit agreement.
Unit operator means the person, association, partnership, corporation, or other business entity designated under a unit agreement to conduct operations on unitized land as specified in such agreement.
Unit well means a well that is:
Unitized land means the part of a unit area committed to a unit agreement.
Unitized substances means deposits of geothermal resources recovered from unitized land by operation under and pursuant to a unit agreement.
Working interest means the interest held in geothermal resources or in lands containing the same by virtue of a lease, operating agreement, fee title, or otherwise, under which, except as otherwise provided in a unit agreement, the owner of such interest is vested with the right to explore for, develop, produce, and utilize such resources. The right delegated to the unit operator as such by the unit agreement is not to be regarded as a working interest.
43 C.F.R. §3280.2