High pressure jet drilling effect in chalk and alteration of local geomechanics properties surrounding the radial hole

Maiya Medetbekova*, Helle Foged Christensen, Frédéric Amour, Saeed Salimzadeh, Hamid Nick

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

This study presents an improved understanding of how high-velocity fluid jet affects the mechanical properties of chalk, building a solid ground for the borehole stability analysis. Our laboratory experiments on water and acid-aided water jet-drilling of chalk samples have shown that high-pressure jet drilling alters the local mechanical properties of the chalk, resulting in a significant weakening of strength properties (tensile, uniaxial/triaxial compressive and pore collapse stress) in close proximity of the jet hole. Acid-aided water has even more impact on chalk matrix as revealed by Scanning Electron Microscopy (SEM) analysis. Numerous micro-perforations are found on the surface of microsparites (calcite). However, no extensive dissolution of calcite cement was observed in the chalk matrix. Results show that mechanical properties degradation is the outcome of both dissolution of the cementation and micro-perforations created on the calcite surface.
Original languageEnglish
Article number105954
JournalInternational Journal of Mechanical Sciences
Volume191
Number of pages19
ISSN0020-7403
DOIs
Publication statusPublished - 2021

Keywords

  • Radial jet drilling
  • Chalk
  • Chalk dissolution
  • Strength/stiffness weakening
  • Damage

Fingerprint Dive into the research topics of 'High pressure jet drilling effect in chalk and alteration of local geomechanics properties surrounding the radial hole'. Together they form a unique fingerprint.

Cite this