WorldWide Drilling Resource

Going Deeper to Investigate Earthquakes Triggered by Reservoirs Compiled by Caleb Whitaker, Associate Editor WorldWide Drilling Resource ® The Koyna Dam located in Maharashtra, India, is one of the world’s most notable examples of a dam t ied t o Rese r vo i r Tr i gge r ed Seismicity (RTS), which is a theory suggest ing large reservoirs l ike the Koyna holding immense amounts of water can crack and fis- sure the surrounding earth when water levels increase and decrease over time; in some cases, this can cause weaknesses in the surround- ing rock mass and trigger earthquakes. Koyna Dam was built in 1962, and five years later, a major earthquake thought to be associated with RTS occurred. Since then, many smaller earthquakes have continued occurring in the area. A scientific drilling investigation in the Koyna region is seeking to provide a bet- ter understanding of the mechanisms involved with earthquakes associated with RTS by developing a forecast model and assessing earthquake hazards. After drilling nine test holes since 2012, scientists zeroed in on a site with great potential for the project in the village of Gothane. Scientists believe it is close enough to a fault zone to generate a strong enough earthquake capable of yielding vast amounts of data related to how the surrounding soil shakes and what kind of gases, water pressure, and temperatures exist at the focus of an earthquake. The main objective is to drill a deep borehole. A research laboratory at Karad will serve as the operational center for carrying out the research activities relat- ed to seismic, deep drilling, borehole investigations, core analysis, and research in associated fields. It is hoped cores obtained from the project will also pro- vide crucial insights into volcanism, mass extinction, thermal structure and state of stress in the lithosphere, the geothermal potential of the West Coast Belt, and the geothermal record of climate change in the region. A drilling rig, typically used to drill for crude oil on India’s western coasts and sometimes out at sea, has been tasked with the mission to drill the first stage of the deep depths envisioned for the project. Assuming everything goes as planned, Indore-based Shivganga Drilling Company will have completed a borehole to a depth of nearly two miles this year. If this initial drilling venture proves to be a success, it will pave the way for deeper operations in the future, which will attempt to drill to a depth of more than three miles and gain valu- able information about earthquakes as a result. The Koyna Dam, courtesy of NichAlp. New & Used Bits, HDD Bits & Tools, Drag Bits & Wings, Bolt-On Drag Bits, Reverse Circulation Tools, Hole Openers, Claw Bits, Stabilizers, Subs, Custom Tooling & Welding, Hammer Bits, Drill Collars, Pipe Wipers, and Drill Pipe. Office: (661) 834-4348 Rod Henderson / Eran Henderson 661-201-6259 • 661-330-0790 sales@bitcobits.com www.bitcoinc.us 27 WorldWide Drilling Resource ® DECEMBER 2017