Subsur fac e Ge ologic Char ac te r ization of Johnson Co., T - PowerPoint PPT Presentation

Ha r ve y S. E a stman, PhD Albuque r que , NM T imothy Mur in, NE T L -AE COM, Pittsbur gh, PA Subsur fac e Ge ologic Char ac te r ization of Johnson Co., T e xas, in Suppor t of Induc e d Se ismic ity Mode ling Top left and bottom right are from Frohlich, 2013, Texas Induced Seismicity Webinar

F or t Wor t h B asi n, T exas Study area and structural features of the basin. Elevation contours are on top of the Ellenburger Group. From Montgomery et al., 2005. 2

St r ess Injection Well Surface Barnett Shale Ellenburger Group Stress builds up along existing faults until it is relieved by an earthquake. This stress is often transferred along faults into the basement rocks. 3

St r ess R el i ef Injection Well Surface Barnett Shale Ellenburger Group Stress may be relieved by the injection of produced water into the Ellenberger Group, which may migrate along the fault plane into Barnett Shale . This additional water in the Barnett Shale may reduce gas production rates and result in additional costs for water disposal. (Louck, 2017) 4

St r uct ur e Map of t he F or t Wor t h B asi n Area of the Barnett Shale is outlined in blue. Area of primary shale-gas production is in yellow. Dallas, TX Elevation contours are on top of the Ellenburger Group. Modified from Montgomery et al., 2005. 5

Maps of E ar t hquake E pi cent er s i n t he F or t Wor t h B asi n Re d c ir c le s r e pr e se nt e a r thquake e pic e nte r s, 2009 to 2010 Red circles – earthquake epicenters; Yellow squares (to right) – Injection wells; White triangles (to left) are seismic stations; Green lines – known faults. From Justinic et al. (2013) and Frohlich et al. (2015). 6

P ur pose • Create a Geologic Characterization of the Subsurface in Support of Seismic Modeling – Geologic data is critical for this study • Rock types – Thickness and elevation of rock types – Depth to basement rocks – Location of faults, particularly unmapped faults 7

P r ocedur e • Collect and Evaluate Geologic Data – Collect geophysical logs and well data reports from Johnson County • Texas Railroad Commission (RRC) Website • IHS Database • Texas Bureau of Economic Geology – Subsurface geology determined principally from nearly 300 Geophysical Logs, coordinated with about 350 well data reports. – Evaluate geophysical logs and well data reports for depth to geologic units 8

Wel l s U sed for Geol ogi c Dat a Map shows cross section lines A-A’ and B-B’ 9

T ypi cal L i t hol ogi c Sect i on for J ohnson Count y, T exas 10

Major Geol ogi c U ni t s and U ni t T hi cknesses NR - Not relevant, ND - Not determinable Unit names based on geologic descriptions in Turner, 1957. The Marble Falls is, in part, Pennsylvanian. 11

Map of Cross Sections prepared for the Johnson County Study 12

Cr oss Sect i on A-A’ – SW t o NE 13

Cr oss Sect i on B -B ’ – NW t o SE 14

St r uct ur e Cont our Map – Sur face of t he B ar net t Shal e Map shows wells used for the map, surface contours, and potential faults based on the shape of the contours. 15

St r uct ur e Cont our Map: Sur face of t he Or dovi ci an (E l l enbur ger ) Map shows wells used for the map, surface contours, and potential faults based on the shape of the contours. 16

Structure map on the 6000 - Ellenburger Group with 5000 - faulting of Turner (1957) and the current fault interpretation super- imposed on the map. Note that the current fault interpretation is considered uncertain due to the subtle changes in the Ordovician (Ellenburger) surface. 17

Summar y • Geologic Characterization of the Subsurface of Johnson County – Shows changes in thickness, extent, and elevation of units through cross sections and formation surface maps • Barnett, Ordovician (Ellenburger), Cambrian, and Precambrian basement – Shows potential and known faults in Johnson County – Data can be used to study induced seismicity and potentially to mitigate the effects of deep disposal of produced water • Compilation of Geologic Data – This data may be of interest to other researchers studying the geology of the Fort Worth Basin 18

Nor ther n Oklahoma-Souther n K ansas Study Structure contour map on top the Mississippian Limestone, Kansas-Oklahoma Mapped faults from Mid-continent faults database and Oklahoma faults database (Oklahoma Geologic Survey). This geologic study in support of induced seismicity was well underway at the time Dr. Eastman leftAECOM in September 2016. 19

Acknowledgements Project Lead: Dustin Crandall, NETL, Morgantown, WV This technical effort was performed in support of the National Energy Technology Laboratory’s ongoing research under the RES contract DE-FE0004000. This project was funded by the Department of Energy, National Energy Technology Laboratory, an agency of the United States Government, through a support contract with AECOM. Neither the United States Government nor any agency thereof, nor any of their employees, nor AECOM, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. 20