WAIS Document Retrieval[Code of Federal Regulations] [Title 43, Volume 2] [Revised as of October 1, 2007] From the U.S. Government Printing Office via GPO Access [CITE: 43CFR3137.91] [Page 404] TITLE 43--PUBLIC LANDS: INTERIOR CHAPTER II--BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR PART 3130_OIL AND GAS LEASING: NATIONAL PETROLEUM RESERVE, ALASKA-- Table of Contents Subpart 3137_Unitization Agreements_National Petroleum Reserve-Alaska Sec. 3137.91 When will BLM allow a well previously determined to be a non-unit well to be used in establishing or modifying a PA? If you, as the unit operator, complete sufficient work so that a well BLM previously determined to be a non-unit well now meets the productivity criteria, you must demonstrate this to BLM within 60 calendar days after you determine that the well meets the productivity criteria. You must then modify an existing participating area or establish a new participating area (see Sec. 3137.84 of this subpart).