Use of borehole imaging to improve understanding of the in-situ stress orientation of Central and Northern England and its implications for unconventional hydrocarbon resources

Abstract New interest in the potential for shale gas in the United Kingdom (UK) has led to renewed exploration for hydrocarbons in the Carboniferous age Bowland–Hodder shales under Central and Northern England. Following an incidence of induced seismicity from hydraulic fracturing during 2010 at Preese Hall, Lancashire, the publically available databases quantifying the in-situ stress orientation of the United Kingdom have shown to be inadequate for safe planning and regulation of hydraulic fracturing. This paper therefore reappraises the in-situ stress orientation for central and northern England based wholly on new interpretations of high-resolution borehole imaging for stress indicators including borehole breakouts and drilling-induced tensile fractures. These analyses confirm the expected north northwest – south southeast orientation of maximum horizontal in-situ stress identified from previous studies (e.g. Evans and Brereton, 1990). The dual-caliper data generated by Evans and Brereton (1990) yields a mean SHmax orientation of 149.87° with a circular standard deviation of 66.9°. However the use of borehole imaging without incorporation of results from older dual-caliper logging tools very significantly decreases the associated uncertainty with a mean SHmax orientation of 150.9° with a circular standard deviation of 13.1°. The use of high-resolution borehole imaging is thus shown to produce a more reliable assessment of in-situ stress orientation. The authors therefore recommend that the higher resolution of such imaging tools should therefore be treated as a de-facto standard for assessment of in-situ stress orientation prior to rock testing. Use of borehole imaging should be formally instituted into best practice or future regulations for assessment of in-situ stress orientation prior to any hydraulic fracturing operations in the UK.

[1]  Stress maps in a minute: The 2004 world stress map release , 2004 .

[2]  Richard J. T. Klein,et al.  Regional state of stress in Western Europe , 1986 .

[3]  R. Hillis,et al.  Present-day stress field of Southeast Asia , 2010 .

[4]  Mark D. Zoback,et al.  Drilling-induced tensile wall-fractures: implications for determination of in-situ stress orientation and magnitude , 1999 .

[5]  M. P. Ekstrom,et al.  Formation Imaging With Microelectrical Scanning Arrays , 1987 .

[6]  J. Harrington,et al.  The role of stress history on the flow of fluids through fractures , 2012, Mineralogical Magazine.

[7]  Sam Holloway,et al.  Pressure constraints on the CO2 storage capacity of the saline water-bearing parts of the Bunter Sandstone Formation in the UK Southern North Sea , 2014 .

[8]  Larry G. Mastin,et al.  Well bore breakouts and in situ stress , 1985 .

[9]  Liam G. Herringshaw,et al.  Oil and gas wells and their integrity : implications for shale and unconventional resource exploitation , 2014 .

[10]  S. Prensky,et al.  Advances in borehole imaging technology and applications , 1999, Geological Society, London, Special Publications.

[11]  Z. Shipton.  Shale gas extraction in the UK: a review of hydraulic fracturing. , 2012 .

[12]  B. Baptie.  Seismogenesis and state of stress in the UK , 2010 .

[13]  C. Evans,et al.  In situ crustal stress in the United Kingdom from borehole breakouts , 1990, Geological Society, London, Special Publications.

[14]  Stephen H. Hickman,et al.  Stress‐induced borehole elongation: A comparison between the four‐arm dipmeter and the borehole televiewer in the Auburn Geothermal Well , 1985 .

[15]  Andreas Barth,et al.  Global crustal stress pattern based on the World Stress Map database release 2008 , 2010 .

[16]  O. Heidbach,et al.  Tectonic stress in the Earth’s crust: advances in the World Stress Map project , 2003, Geological Society, London, Special Publications.

[17]  I. J. Andrews,et al.  The Carboniferous Bowland Shale gas study: geology and resource estimation , 2013 .

[18]  Carmen Garcia-Carballido,et al.  Data Management and Quality Control of Dipmeter and Borehole Image Log Data , 2010 .

[19]  G. Williams,et al.  UK data and analysis for shale gas prospectivity , 2010 .

[20]  J. Williamson,et al.  In-situ stress orientations in the UK Southern North Sea: Regional trends, deviations and detachment of the post-Zechstein stress field , 2015 .

[21]  L. Mastin.  Effect of borehole deviation on breakout orientations , 1988 .

[22]  A. Becker,et al.  Contemporary in situ stress determinations at three sites in Scotland and northern England , 2001 .

[23]  Daniel Moos,et al.  Utilization of observations of well bore failure to constrain the orientation and magnitude of crustal stresses: Application to continental, Deep Sea Drilling Project, and Ocean Drilling Program boreholes , 1990 .

[24]  D. I. Gough,et al.  Northeast-southwest compressive stress in Alberta evidence from oil wells , 1979 .

[25]  O. Heidbach,et al.  Present-day stress orientation in the Molasse Basin , 2010 .

[26]  R. Hillis,et al.  In situ stresses in the North Sea and their applications: petroleum geomechanics from exploration to development , 2005 .

[27]  P. Gaillot,et al.  Contribution of borehole digital imagery in core-log-seismic integration , 2007 .

[28]  J. Lauterjung,et al.  The German Continental Deep Drilling Program KTB: Overview and major results , 1997 .

[29]  O. Stephansson,et al.  Global patterns of tectonic stress , 1989, Nature.

[30]  E. R. Leeman,et al.  A Technique For Determining the Complete State of Stress In Rock Using a Single Borehole , 1966 .

[31]  M. Gölke,et al.  ORIGINS OF THE EUROPEAN REGIONAL STRESS FIELD , 1996 .

[32]  Karl Fuchs,et al.  World Stress Map of the Earth: a key to tectonic processes and technological applications , 2001, Naturwissenschaften.

[33]  D. Bigby.  Absolute stress and stress change measurements in British Coal Measures , 1992 .