EGS Collab Testbed 2 Preliminary Test Wells Locations and Orientations

The EGS Collab project is evaluating a site for Experiment 2 (hydraulic fracturing/shearing) at a depth of 1.25 km in the Sanford Underground Research Facility (SURF) on the 4100 Level. Two early test holes were drilled in an alcove (formerly known as Battery Charging Station) near Yates Shaft. One of the test hole is about 50 m where as the other hole is about 10 m. This submission package includes well head locations, total lengths of boreholes, their orientations (gyro data). The reported boreholes orientation data were primarily obtained with REFLEX GYRO (TM) survey right after the completion of each hole. Well head locations were ascertained by Laser/LiDAR survey of the drift around the Testbed 2. Note: The coordinate system used is local Homestake Mine Coordinate (HMC) system from an old gold mine that was in operation for over 100 years.

EGS Collab项目正在桑福德地下研究设施（Sanford Underground Research Facility, SURF）的4100层，对深度1.25千米的2号实验场地（水力压裂/剪切实验场地）开展评估。该项目在耶茨竖井附近的一处壁龛（原名为充电站）内钻取了两个早期测试孔，其中一个测试孔深度约50米，另一个约10米。本提交数据包包含井口位置、钻孔总长度以及钻孔方位（陀螺测量数据）。所提交的钻孔方位数据主要通过在每个钻孔完工后立即开展的REFLEX GYRO（TM）测量获取。井口位置则通过对2号试验台周边平巷开展的激光/LiDAR测量确定。注：本次使用的坐标系为拥有百余年运营历史的霍姆斯特克老金矿的本地霍姆斯特克矿井坐标系（Homestake Mine Coordinate, HMC）。