Longwall-Induced Deformations and Shale Gas Well Casing Stresses: Engineering Principles

Details

• Personal Author:
  Su DW ; Zhang P
• Description:
  This paper summarizes important findings from the ongoing National Institute for Occupational Safety and Health (NIOSH) gas well stability research. Over the past seven years, field instrumentation results from NIOSH case studies and active mine-by case studies indicate that, under shallower covers, the measured horizontal displacements within the longwall abutment pillar are one order of magnitude higher than those measured under deep cover. Longwall-induced horizontal displacements occur along weak-to-strong rock interfaces; the sharper the bending stiffness contrast across the interfaces, the larger the longwall-induced horizontal displacements. Longwall-induced vertical compressions under shallower covers are, on the other hand, one order of magnitude lower than those under deep covers. Subsurface strata dip may magnify or reduce longwall-induced horizontal displacements. Uncemented production casings serve to uncouple longwall-induced deformations and stresses from the production casing. A case study is presented to illustrate the importance of leaving the production casing uncemented. [Description provided by NIOSH]
• Subjects:
  Geology Occupational Health Safety
• Keywords:
  Environmental Stress Longwall Mining Mining Engineering Pillar Mechanics Rock Mechanics
• Series:
  Mining Publications
• ISBN:
  9780979497582
• Publisher:
  American Rock Mechanics Association (ARMA)
• Document Type:
  Text
• Genre:
  Proceedings
• Place as Subject:
  OSHA Region 3 ; Pennsylvania
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  PMRD - Pittsburgh Mining Research Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• NIOSHTIC Number:
  nn:20068944
• Citation:
  57th US Rock Mechanics/Geomechanics Symposium, June 25-28, 2023, Atlanta, Georgia. Alexandria, VA: American Rock Mechanics Association (ARMA), 2023 Jun; :ARMA-2023-0037
• Federal Fiscal Year:
  2023
• NORA Priority Area:
  Mining ; Oil and Gas Extraction
• Peer Reviewed:
  False
• Source Full Name:
  57th US Rock Mechanics/Geomechanics Symposium, June 25-28, 2023, Atlanta, Georgia
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:69e09ae4e8042112765120bd9980e430140903a354a4ab5e86c98ae84b2edf72bb638ffb0cc5e6d38fd90fade606439ebcc72d908b5396d0ab111c8465284d05
• Download URL:
  https://stacks.cdc.gov/view/cdc/215624/cdc_215624_DS1.pdf
• File Type:
  [PDF - 968.66 KB ]