Shale – Mudrock Fracture Research

Shale Fracture Research Program

Production of hydrocarbons from shale and other fine-grained source rocks has developed rapidly over the last decade. While technological breakthroughs in well completions led the initial expansion, recognition that natural fractures are important in these reservoirs has increased. Natural fractures can enhance permeability and may interact with hydraulic fractures during stimulation.

Julia F. W. Gale

Julia F. W. Gale leads the SDI effort in shale natural fracture research. The first phase of the research has been to establish the broad characteristics of fractures in shales; this work has culminated in a major review paper, Gale et al., in press.

The next phase, currently underway, is to examine shale fracture and host rock attributes more closely. In addition to collection of data in core and outcrop on fracture size–width, length, height—and on spacing and openness attributes, the group is now using fluid inclusions and stable isotope geochemistry to establish conditions and timing of fracture formation and exploring the nature of fluids from which fracture cements precipitate. Using the burial history for the samples and temperature information from fracture cements allows us to establish fracture timing, which in turn leads to better understanding of fracture mechanisms.

Gale works closely with Jon Olson on how attributes of natural fractures may interact with hydraulic fractures.

Gale also collaborates on projects examining the potential link between seismicity and fluid production/injection in basins with high unconventional reservoir activity.

Gale continues to be involved in fundamental research on fracture size scaling and spatial arrangement.

Gale was an AAPG Distinguished Lecturer in 2013-2014. She serves as an Associate Editor for AAPG Bulletin. Her 2010 paper Modeling fracture porosity evolution in dolostone published in the Journal of Structural Geology was awarded the 2011 Publication Award, in recognition of exemplary publication of scientific or economic impact, from the Bureau of Economic Geology, The University of Texas.

The following papers reflect some of Gale’s current research interests:

  • Gale, J. F. W., Laubach, S. E., Olson, J. E., Eichhubl, P., and Fall, A., 2014, Natural fractures in shale: A review and new observations. AAPG Bulletin, Special Issue on Faulting and Fracturing in Shale and Self-Sourced Reservoirs. v. 98, no. 11, p. 2165-2216. doi: 10.1306/08121413151 | view at GSW
  • Gasparrini M., Sassi W., and Gale J. F.W. 2014, Natural sealed fractures in mudrocks: A case study tied to burial history from the Barnett Shale, Fort Worth Basin, Texas, USA. Marine and Petroleum Geology 55, 122-141..
  • Gale, J. F. W., and Holder, J., 2010, Natural fractures in some U.S. shales and their importance for gas production: The Geological Society, London, Petroleum Geology Conference Series, v. 7, p. 1131‒1140. doi: 10.1144/0070899
  • Gale, J. F., Lander, R. H., Reed, R. M., and Laubach, S. E., 2010, Modeling fracture porosity evolution in dolostone. Journal of Structural Geology, v. 32, no. 9, p. 1201-1211. doi:10.1016/j.jsg.2009.04.018.
  • Gale, J. F. W., Reed, R. M., and Holder, J., 2007, Natural fractures in the Barnett Shale and their importance for hydraulic fracture treatments: AAPG Bulletin, v. 91, no. 4, p. 603–622.
  • Gale, J. F. W., 2002, Specifying lengths of horizontal wells in fractured reservoirs: Society of Petroleum Engineers Reservoir Evaluation and Engineering, v. 5, no. 3, p. 266–272.