Modern Compass Improves Oilfield Productivity, Cuts Costs

USGS comments that multiple reservoirs of oil and gas can be now be accessed from a single platform by drilling vertically and then horizontally, but drill operators need to know which way their drill bits are going to maxi­mize production and avoid collisions with other wells. One way to accomplish this important task is to install a magnetometer—a sort of modern-day compass—in a drill-string instrument package that follows the drill bit.

USGS contributes by monitoring the geomag­netic field every single second at magnetic observatories throughout the country. Through a process called geomag­netic referencing, simultaneous measurements of the mag­netic field in the drill hole are combined with those from magnetic observatories at the earth’s surface to produce a highly accurate estimate of the drill bit position and direc­tion. Monitoring is critical because the earth’s magnetic field changes constantly across the world as a result of fac­tors like periodic daily tides or rapid magnetic storms that are related to the 11-year sunspot solar cycle.

“Drill-bit positioning requires directional accu­racy of a fraction of a degree, and this can be accom­plished with advanced technology and expert understand­ing of the earth’s magnetic field,” said Carol A. Finn, leader of the USGS Geomagnetism Group. “USGS opera­tional systems measure the magnetic field on a continu­ous basis. These data are provided as a service to research scientists, civilian and defense government agencies, and to customers in the private sector, including the oil and gas drilling industry.”