Downhole Laser System With an Improved Laser Output Production and Data Collection

This patent-pending technology establishes a novel system and method for laser induced breakdown spectroscopy (LIBS) applications. The technology is available for licensing and/or further collaborative research from the U.S. Department of Energy’s National Energy Technology Laboratory.

Challenge

Low-cost, efficient monitoring of remote locations has and continues to be highly sought in the industry. For example, drilling production or injection wells for oil/gas extraction or carbon dioxide (CO2) storage always has the potential for leakage into the surrounding formations and environment. The ability to measure the subsurface fluids in and around the injection/production area before and after subsurface activities becomes more important when there is a suspected leak. Current downhole monitoring systems rely on bulk parameters such as pH and conductivity. Lab based systems can provide trace element measurements of subsurface fluids but require fluids to be taken from the field and digested prior to measurement. A system that can provide trace element measurements in real time while deployed in the subsurface is potentially of great value.

Current diode pumped solid state (DPSS) laser systems used for laser induced breakdown spectroscopy applications in fluid system measurements have numerous limitations. First, the systems are susceptible to dimensional changes caused by temperature and pressure swings in fluctuating environments in downhole applications. A second issue is the size of the laser spark that is produced in the fluid for measurements affecting signal strength. The third issue is the efficient collection and transmission of the plasma emission for analysis.