New maps reveal safe locations for wastewater injection

New maps created by Stanford scientists reveal safe locations for wastewater injection
New stress maps of Texas and Oklahoma, with black lines indicating stress orientation. Blue-green colors indicate regions of extension in the crust, while yellow-orange areas are indicative of crustal compression. Credit: Jens-Erik Lund Snee

Stanford geophysicists have compiled the most detailed maps yet of the geologic forces controlling the locations, types and magnitudes of earthquakes in Texas and Oklahoma.

These new "stress maps," published in the journals Geophysical Research Letters and Bulletin of the Seismological Society of America, provide insight into the nature of the faults associated with recent temblors, many of which appear to have been triggered by the injection of wastewater deep underground.

"These maps help explain why injection-induced earthquakes have occurred in some areas, and provide a basis for making quantitative predictions about the potential for seismic activity resulting from ," said study co-author Mark Zoback, the Benjamin M. Page Professor of Geophysics in Stanford's School of Earth, Energy & Environmental Sciences.

To create these stress maps, Zoback and his graduate students Jens-Erik Lund Snee and Richard Alt interpreted data from different parts of Texas and Oklahoma donated by oil and gas companies. "Companies routinely collect data that can be used for assessing the state of stress in the Earth as part of their normal oil and gas operations," Lund Snee said.

When combined with information about the faults present in a given area, the scientists were able to assess which faults are likely to be problematic and why. In the areas where induced earthquakes have occurred in Texas and Oklahoma, the Stanford scientists show that a relatively small increase of pore pressure - the pressure of fluids within the fractures and cavities of rocks - would have been sufficient to trigger slip.

In a related paper published recently in the journal Geology, graduate student F. Rall Walsh and Zoback present a methodology for assessing which faults are susceptible for triggering and which are not.

The Stanford scientists also found that many of the recent earthquakes in Texas that have been suspected as being triggered by wastewater injection occurred on faults that - according to the new map - have orientations that are nearly ideal for producing earthquakes. Hence, doing this kind of study in advance of planned injection activities could be very helpful.

"By identifying which faults are potentially active in advance, companies and regulators can avoid problematic faults during fluid and prevent the induced earthquakes from happening before they do," Zoback said.


Explore further

Satellites help link Texas earthquakes to wastewater injection, scientists say

More information: Jens-Erik Lund Snee et al. State of stress in Texas: Implications for induced seismicity, Geophysical Research Letters (2016). DOI: 10.1002/2016GL070974

F. Rall Walsh et al. Probabilistic assessment of potential fault slip related to injection-induced earthquakes: Application to north-central Oklahoma, USA, Geology (2016). DOI: 10.1130/G38275.1

Citation: New maps reveal safe locations for wastewater injection (2016, November 11) retrieved 25 August 2019 from https://phys.org/news/2016-11-reveal-safe-wastewater.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
274 shares

Feedback to editors

User comments

Nov 12, 2016
Out of sight, out of mind.

Until our successors find it.

This reveals the shallow character of folk whose only thought is for money.

Nov 14, 2016
@ gkam; totally agree.
And the sad part is most of these people are religious and say they care about things other than themselves---our elections showed what's really in their hearts right? As you said it: me and my family and more money (I don't really care about others I just say I do once a week)

Nov 14, 2016
BTW; its a good publication article by the authors

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more