Laserfiche WebLink
Consequently, AMSO feels that the insulation provided by the VIT, the space between <br />the VIT and the 113/4-inch steel casing, and the three inches of cement outside of the steel <br />casing will provide thermal containment of hot fluids transported through the tubing <br />within the VIT. <br />Also, the redundancy provided by dual-wall of the VIT, the steel casing, and the <br />cemented annulus is considered adequate to contain any liquids (contaminants) within the <br />heater-producer well. <br />4. The submitted information discussed the concept of the development of a "rind" <br />resulting from the heat and pressure that occurs during the retort process. The plan <br />relies on the development of this "rind" in order to contain the hydrocarbons and their <br />by products; to keep groundwater out of the retort area; and presumably to prevent <br />contaminants from entering the adjacent groundwater. Please address the following <br />questions: <br />• a) At what temperature does the "rind" develop and what by products or <br />contaminants may escape into the surrounding groundwater prior to <br />development of this rind? <br />• b) Is this rind a permanent feature? Will it keep the affected area isolated after <br />retort is complete? <br />• c) If it is permanent, how will it impact the f low of groundwater? <br />• d) If it is not permanent, how will contaminants be prevented from affecting <br />groundwater? <br />• e) Is there any risk of the thermomechanical fragmentation fracturing the <br />"rind?" <br />AMSO Response: <br />First, it is not correct that our plan depends upon the development of a "rind". The rind <br />may or may not develop. We anticipate that it will develop and enhance the natural high- <br />confinement characteristics of the illite shale, but it is not essential for the success of the <br />process or for protection of aquifers. Nevertheless, we will use our Pilot Test to improve <br />our understanding of the rind concept. <br />As mentioned in the POD, when heated shale is confined by the surrounding unheated <br />shale, the heated shale cannot expand and instead collapses its internal porosity, thereby <br />forming a rind. The primary benefit of the rind relates to expelling pore water from the <br />advancing retort boundary. <br />It is very unlikely that the R1 zone will produce any free water before, during, or after the <br />retort. Three wells in the retort area have found insignificant groundwater. Core drying <br />tests measured an average free water content of 3.5 percent by weight in the retort <br />interval, and there was less than 0.03 gal/minute water inflow into the TM-I test well. <br />a) AMSO has not determined precisely at what temperature the rind might develop, but it <br />is likely lower than 100 T. The rind's primary attribute is to exclude water from entering <br />110 East 3`a Street. Suite 201 P.O. Box 1470, Rifle CO 816501phone•970-6254324 facsimile•970-62511318 3