by Stephen Forrester

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Today, let's talk about gyroscopes in the energy industry. The University of Houston presents this series about the machines that make our civilization run, and the people whose ingenuity created them.

"Gyroscope" isn't a household word, even though they're in cell phones, planes, cars, and boats. They also help us drill tens of thousands of feet into the earth. Though renewables are changing how we look at energy, many of the modern comforts we enjoy are still powered by resources found deep in the ground.

More than 100 years ago, drilling surveys involved dropping a glass bottle filled with acid into the ground. The acid settled at an angle in the bottle parallel to the angle of inclination, and after a while, the acid etched a line. Inclination in a well is how many degrees the hole deviates from a vertical path.

Acid bottle well survey instruments.

Photographic survey instruments quickly replaced this method. They measured both inclination and cardinal direction, which told the person if the well was going north, south, east, or west. These instruments were very fragile, and both methods were inaccurate and prone to human error.

Elmer Sperry, a famous inventor, designed the first wellbore gyroscopic survey tool in 1929. A gyroscope is a wheel that spins around one axis but is free to rotate about one or more axes. The inertia of the spinning wheel keeps its axis pointing in a known direction established by the surveyor. This made gyro surveying more accurate than anything previously available.


Drilling was changing, and gyros had to get smaller. People also wanted more detailed information on what was happening in the ground. New gyros were made, though all were based on the same principles. Sensors that collected data on the earth's rotational field replaced earlier systems. The north-referencing sensor perfectly detected the earth's rotational velocity without variance. Eventually, gyros could be used to collect data while drilling, instead of afterward.

Having such high accuracy and precision is why gyros are used in aircraft instruments, the Hubble Space Telescope, and missiles. During the drilling process, a gyro is used to better understand a well's placement. This is very important to the energy industry.

If a well is in the right place--the production zone--the first time, extra equipment and materials aren't necessary, meaning less risk and less impact to the environment. And, if we produce more because we're in a target zone, we get a better return on the money we spend. It's that easy, and it makes sense.

A gyro is one of the keys to making it happen.

Solid-state gyro technology is one of the latest and most exciting new developments in the world of drilling. Solid-state gyros are even smaller, stronger, and more accurate than earlier designs.

Gyros will help ensure that better wells are drilled, placed where they need to be the first time. As we mentioned, there are also many other places where gyros are important. And so, the wheels of innovation, like a gyro, will keep spinning.

I'm Stephen Forrester, from the University of Houston, where we're interested in the way inventive minds work.

(Theme music)

Slav, Irina. "The Truth About The World's Deepest Oil Well." Yahoo! Finance, Yahoo!, 19 Nov. 2019. The depth of a well is typically reported in two ways: true vertical depth and measured depth. The deepest well by true vertical depth exceeded 35,000 feet, while the measured depth of the longest wells was more than 46,000 feet.

MacFarland, Allen. "U.S. Energy Information Administration - EIA - Independent Statistics and Analysis." The amount of energy consumed across all renewable categories has grown modestly in the U.S. and abroad, while coal consumption has fallen dramatically. Petroleum and natural gas, however, still comprise the largest chunk of total energy consumption.

Griswold, E.H. "Acid Bottle Method of Subsurface Well Survey and Its Application." Transactions of the AIME, vol. 82, no. 01, 1929. In an interesting window to the past, the author mentioned gyroscopic compasses, but noted that they were generally too expensive.

Devenish, Greg, et al. "Directional Drilling." IADC Drilling Manual, 12th ed., vol. 1, International Association of Drilling Contractors, 2015, pp. DD-1-DD-10. IADC provides historical context in the IADC Drilling Manual.

"Case Files: Elmer A. Sperry (Gyroscopic Compass)." The Franklin Institute. "Elmer Ambrose Sperry." Wikipedia, Wikimedia Foundation. Elmer Ambrose Sperry was coinventor of the gyrocompass and founder of Sperry Gyroscope Company.

Weston, John Lionel, et al. "New Gyro While Drilling Technology Delivers Accurate Azimuth and Real-Time Quality Control for All Well Trajectories." SPE Drilling & Completion, vol. 29, no. 03, 2014. Gyrodata, Inc. pioneered the first gyro-while-drilling system, which allowed drillers to use real-time gyroscopic steering and surveying data while drilling, in 2002.

"Gyroscopes." Hubble Space Telescope, ESA/Hubble | ESA/Hubble. "Missile Guidance." Wikipedia, Wikimedia Foundation. The Hubble Space Telescope has a total of six gyroscopes. Missiles, including intercontinental ballistic missiles, use inertial guidance to calculate the location of the missile.

Beattie, Keith, et al. "All-Attitude Gyro While Drilling Technology Provides Accurate Surveys in High Angle East/West Directional Wellbores Delivering Reduced Costs and Increasing the Length of the Producing Zone." SPE/IADC Drilling Conference and Exhibition, 2015. One method of improving production is by extending a producing zone, with gyro-while-drilling technology proving successful in this regard.

"Vibrating Structure Gyroscope." Wikipedia, Wikimedia Foundation. Weston, John, and Adrián Ledroz. "The Combination of Solid-State Gyroscopic and Magnetic Surveys Provides Improved Magnetic-Survey Data and Enhanced Survey Quality Control." SPE Drilling & Completion, 2019. We're using "solid-state gyroscope" to refer to a Coriolis vibratory gyroscope, though there are several other types. Advanced solid-state gyroscopic sensors have "become both a viable and practical option for high-accuracy wellbore placement, with the potential to outperform traditional mechanical gyroscopic systems."

This episode was first aired on February 19, 2020