Laserfiche WebLink
Geothermal Rules <br />Statement of Basis and Purpose <br />Rule 10.2 and its subsections prescribe a mechanical integrity test prior to injecting a fluid <br />to protect against a well failure creating a potential source of underground contamination <br />from the escape of an injected fluid. The 300 psi pressure test was adopted from the Oil <br />and Gas Commission's rules in order to provide a minimum test of the injection piping. <br />Performing the well/aquifer test required by Rule 10.4 is necessary in order to establish <br />hydraulic characteristics of the injection reservoir and to determine the maximum <br />allowable injection pressure. <br />Rules 10.3 and 10.5 provide for equipping a reinjection well so that injection pressure can <br />be monitored and controlled within the limit placed on the injection well. <br />RULE 11 PLUGGING OF GEOTHERMAL WELLS <br />An unused or inoperable geothermal well is potentially hazardous to the public health, <br />ground water resources, and the environment. In order to minimize this hazard, a <br />geothermal well must be plugged and sealed when no longer used or needed. Rule 11.1 <br />specifies that it is the well owner's responsibility to ensure that an unused geothermal well <br />is properly plugged. <br />Rule 11.2 provides general standards for plugging a geothermal well and identifies the <br />reasons for requiring proper well plugging. Detailed construction information is generally <br />needed to ensure that the plugging program accomplishes the stated objectives. <br />Rule 11.2.1 established a minimum plug length of 50 feet because of the potential for <br />higher pressure in a flowing Type A -OS or Type B well and the need to confine the <br />injected fluid to the injection zone of a reinjection well. <br />Plugging operations for a Type A -OS geothermal well are similar to those for a water well <br />and are therefore, under the authority of the State Board of Examiners of Water Well <br />Construction and Pump Installation Contractors. Thus, Rule 11.3 relies on the provisions <br />of the Water Well Construction Rules, 2 CCR 402-2, for plugging a non -flowing Type A - <br />OS geothermal well. <br />The minimum standards of the Water Well Construction Rules, 2 CCR 402-2, are not <br />adequate for plugging a geothermal well producing a hot fluid under pressure or a well <br />which is used for reinjection purposes. Rule 11.4 provides the State Engineer an <br />opportunity to review and approve methods and materials proposed to be used for <br />plugging a Type B, reinjection or flowing Type A -OS well. Submitting a plan and <br />obtaining approval prior to the plugging of a well allows the State Engineer to be aware of <br />and be a witness to the plugging of a geothermal well. <br />Proper plugging of loop -field piping or tubing for a Type A-CLH or Type A-CLV well is <br />explained in Rule 11.5. To protect the ground water resources, public health, and the <br />12 <br />