ANALYSIS OF STRESS, FLOW AND STABILITY AROUND DEEP WELLS

The mechanisms of soil failure and solid particle influx into well-bores penetrating uncemeted and deformable porous media under seepage conditons such as occur in oil recovery from oil sand are considered. A numerical procedure is presented for analyzing the response of soils around deep wells that is suitable for practical applications. The procedure accounts for the plastic failure caused by drilling the well-bore and the tensile failure caused by the seepage forces into the well-bore. The developed model is verified against closed-form solutions and validated by simulating a field problem involving a deep oil well that had experienced sand poduction during its operation. Application of the numerical model indicates that the initiation of soil liquefaction leading to sand production requires the fluid pressure gradient to exceed a certain critical value that is governed by the properties of the formation. The enhancement of permeability within the liquefied zone results in a reduction of fluid pressure gradient that may terminate the inflow of sand into the well. Sand inflow or production can be reactivated if the fluid pressure gradient exceeds a new critical level commensurate with the modified well-bore geometry and formation properties.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00168505
• Corporate Authors:

  Thomas Telford Limited

  London,   United Kingdom 
• Authors:
  • VAZIRI, H H
  • Byrne, P M
• Publication Date: 1990-3

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 63-77
• Serial:
  • GEOTECHNIQUE
  • Volume: 40
  • Issue Number: 1
  • Publisher: Thomas Telford Limited
  • ISSN: 0016-8505

Subject/Index Terms

• TRT Terms: Failure; Flow; Liquefaction; Mathematical models; Seepage; Soil mechanics; Soils; Stability analysis; Stresses; Wells
• Uncontrolled Terms: Models
• Old TRIS Terms: Deep wells
• Subject Areas: Bridges and other structures; Geotechnology; Highways; Hydraulics and Hydrology; I42: Soil Mechanics;

Filing Info

• Accession Number: 00494140
• Record Type: Publication
• Files: TRIS
• Created Date: May 31 1990 12:00AM