Complementing National Oilwell Varco’s (NOV) surface solutions are an array of Downhole Instrumentation (DHI) products for both straight-hole and directional markets.

As a pioneer in downhole electromagnetic (EM) communications for Measurement While Drilling (MWD) tools, NOV DHI serves independent directional drillers with both sales and rental business models through its BlackStar™ EM MWD group. The EM advantage is realized in drilling situations requiring speedy downhole survey data and in situations where aerated or contaminated mud systems make traditional mud-pulsed communications problematic.

Traditional MWD systems transmit information to the surface by sending pressure pulses through the drilling fluids or wire transmission. National Oilwell Varco’s MWD applications involve the sending of measurements made by instruments located at the bottom of the hole back to the surface to allow the crew to understand such things as the location and orientation of the drill bit.

NOV’s Downhole Instrumentation group designs and manufactures steering tools, survey tools (single and multi-shot), and downhole sensors which provide accurate and reliable information on inclination, azimuth, pressure, temperature, and weight on bit, as well as recently added directional sensors for MWD, Wireline, and Rotary Steerable applications. The EM systems then send information to the surface through the earth’s crust utilizing low frequency electromagnetic waves. Information is received at a surface antenna, decoded, and then processed by a computer and distributed to the driller’s readout display without the encumbrance of mud or wire transmission. Such information is critical in directional drilling.