Full text loading...
-
Questioning the Existence of Hydraulic Fracturing-induced LPLD Events in a Barnett Shale, Texas, Microseismic Dataset
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, Sixth EAGE Workshop on Passive Seismic, Jan 2016, Volume 2016, p.1 - 5
Abstract
Summary
Recent studies have identified and characterized a type of seismic event, known as an LPLD event, which have been detected in microseismic data sets acquired during hydraulic fracturing operations (e.g. Das and Zoback, 2011 ; 2013a ; 2013b ; Mitchell et al., 2013 ; Kwietniak, 2015 ). These events have been interpreted to be manifestations of slow-slip along preexisting fractures which are presumed to either be misaligned with respect to the current day principal stress directions or have high clay content ( Das & Zoback, 2013a ; 2013b ). A study by Caffagni et al. (2015) advise that care must be undertaken when analyzing and interpreting such events as regional earthquakes could be misinterpreted as LPLD events in vertical downhole seismic monitoring array data sets.
We here show that signals associated in time with such LPLD events could be observed on many Earthscope USArray stations, even at distances up to 350 km from the injection well. The spatial coverage of the USArray enabled all of the LPLD events to be relocated in the North Texas-Oklahoma region, outside of the stimulated reservoir volume. We conclude that these LPLD events are not directly related to the hydraulic fracture stimulation process or the induced reservoir deformation process.
© EAGE Publications BV