2 Colo. Code Regs. § 402-7-9
Current through Register Vol. 47, No. 20, October 25, 2024
Rule 2 CCR 402-7-9 - Geophysical LogsA. Geophysical logs will be required for all wells permitted pursuant to Section 37-90-137(4), C.R.S. unless there is an existing geophysical log from that aquifer located within 1,320 feet of the proposed well which is acceptable to the State Engineer and is representative of aquifer conditions at the location of the permitted well. The permittee will be responsible for obtaining and submitting a copy of the existing geophysical log unless it is currently available at the Office of the State Engineer.B. If the new well is geophysically logged, the permittee is responsible for obtaining and submitting those required geophysical logs to the State Engineer's Office. The minimum requirement will be for both resistivity and spontaneous potential (SP) logs, which must be obtained prior to the installation of well casing. The resistivity log must record values at approximately one- and three-foot depths of investigation. The vertical scale shall be either one inch equals twenty feet or one inch equals fifty feet. If additional types of logs, including gamma, neutron, porosity, sonic, single-point resistance, and caliper, are obtained, copies of these logs shall also be submitted to the State Engineer's Office. The entire set of logs must be submitted to the State Engineer's Office within sixty days following collection of the data. If a permittee, or an applicant drilling a test hole, desires to use other geophysical logs to meet the minimum requirement, he must apply in writing to the State Engineer and get the approval of the State Engineer prior to well construction. In the event that the data provided contain trade secrets, privileged information, or confidential commercial, financial, geological or geophysical data, the State Engineer shall deny the right of inspection of such data to any person and keep the data confidential pursuant to Section 24-72-204(3)(a)(IV), C.R.S. provided the applicant notifies the State Engineer in writing requesting such protection.C. The State Engineer may require the applicant to submit the geophysical well logs prior to the casing of the production well in order to determine the appropriate producing interval. In such a case, the State Engineer shall inform the applicant of the appropriate producing interval within two working days of receipt by the State Engineer of the geophysical logs.