http://geo.web.ru/db/msg.html?mid=1163901

Project activities are focused on assessing the chance of discovery and, assuming discovery, the range of potential recoverable quantities under a commercial development program.

SPE: Lead A project associated with a potential accumulation that is currently poorly defined and requires more data acquisition and/or evaluation in order to be classified as a prospect.

Project activities are focused on acquiring additional data and/or undertaking further evaluation designed to confirm whether or not the lead can be matured into a prospect. Such evaluation includes the assessment of the chance of discovery and, assuming discovery, the range of potential recovery under feasible development scenarios.

SPE: Play A project associated with a prospective trend of potential prospects, but which requires more data acquisition and/or evaluation in order to define specific leads or prospects.

Project activities are focused on acquiring additional data and/or undertaking further evaluation designed to define specific leads or prospects for more detailed analysis of their chance of discovery and, assuming discovery, the range of potential recovery under hypothetical development scenarios.

http://unece.org/ie/se/pdfs/UNFC/unece_comments_spe_rms2007.pdf (стр. 24)

C учетом изложенного, а также с учетом вот этого:

http://www.kommersant.ru/doc.aspx?DocsID=573511

Я переводил бы как:

Play - прогнозные ресурсы;
Lead - перспективные ресурсы и
Prospect - локализованные ресурсы (последнее также называют, но уже не в терминах оценки запасов, а в терминах ГРР подготовленной к бурению структурой).