Novel Low Cost Method to Install Geophones for CO2 Monitoring

In order to monitor the location of sequested CO2 that has been injected in reservoirs, the most promising technology involves the use of geophones within wellbores. These geophones perform Vertical Seismic Profiling (VSP) and passive seismic monitoring. However, this geophone technology is currently very expensive to apply ¿ drilling a new well or taking a valuable well out of service is costly. Consequently, the technology is seldom employed; making it is very difficult to determine whether the CO2 remains where it is intended. This project will utilize a patented High Pressure Slurry Pump, proven coiled tubing, and a patent-pending supercritical abrasive slurry system to drill low-cost microholes (two inches in diameter) for the permanent installation of small, inexpensive VSP receivers. Phase I demonstrated the drilling process and identified currently-available geophones that can fit inside the tubing at a depth of 2,000 feet. Moreover, the geophones were shown to be capable of monitoring fluids in rock at 4-to-5 times that depth. Phase II will assemble and field-test these combined components, drill up to three wells, equip them with geophones, and conduct a VSP quality-check survey within an existing CO2 flood. Commercial Applications and Other Benefits as described by the awardee: In addition to reducing the cost of CO2 monitoring with VSP, the overall system should find use in conventional oil and gas drilling (vertical and directional), boring, and digging and trenching in hard rock areas; for utility installation of buried pipes and pipelines; and in mining, construction peering, geothermal sinks, and environmental well drilling.