During the commissioning
phase of an oil well, when systems are being set up and tested, Purkis expects operators to drop swarms of
RFID tags three to four times a day, in order to adjust settings. Later, when wells are in production, tags may be sent down the hole once each month, or only as needed, for valve adjustment.
Prototypes of the system are currently in operation, Purkis says, though he declines to reveal which companies tested them besides Marathon Oil. He does indicate, however, that the RFID system was recently shipped to a firm in Canada, as well as to integrated international petroleum company
Saudi Aramco.
What's more, Purkis adds, one major company is presently considering implementing a system to communicate in the other direction—from downhole tools to operators at the top of wells. That firm wants to monitor heat and pressure within the wells, as well how fast fluids flow.
The basic concept is that tools loaded with a large number of RFID tags would be placed into the wells. The battery-operated tools would also be equipped with pressure, temperature and flow sensors. The tools would encode a tag with data recorded by the sensors, then release the tag into the upward flow. At the surface, the tag would pass another
interrogator, which would
read the information encoded on the tag.
With several such devices in the hole, operators could analyze the amount of oil coming from each section, and how fast it flows. That information, the company indicates, would help operators drill more precisely the next time the same well was tapped.
"We are using RFID in a unique way," Purkis states. "Our partners say it will change the way oil wells are drilled and produced in the future."