THERMAL SCIENCE

International Scientific Journal

External Links

WELLBORE STABILITY ANALYSIS IN CHEMICALLY ACTIVE SHALE FORMATIONS

ABSTRACT
Maintaining wellbore stability involves significant challenges when drilling in low-permeability reactive shale formations. In the present study, a non-linear thermo-chemo-poroelastic model is provided to investigate the effect of chemical, thermal, and hydraulic gradients on pore pressure and stress distributions near the wellbores. The analysis indicates that when the solute concentration of the drilling mud is higher than that of the formation fluid, the pore pressure and the effective radial and tangential stresses decrease, and v. v. Cooling of the lower salinity formation decreases the pore pressure, radial and tangential stresses. Hole enlargement is the combined effect of shear and tensile failure when drilling in high-temperature shale formations. The shear and tensile damage indexes reveal that hole enlargement occurs in the vicinity of the wellbore at an early stage of drilling. This study also demonstrates that shale wellbore stability exhibits a time-delay effect due to changes in the pore pressure and stress. The delay time computed with consideration of the strength degradation is far less than that without strength degradation.
KEYWORDS
PAPER SUBMITTED: 2015-12-14
PAPER REVISED: 2015-12-20
PAPER ACCEPTED: 2015-12-25
PUBLISHED ONLINE: 2016-09-24
DOI REFERENCE: https://doi.org/10.2298/TSCI16S3911S
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2016, VOLUME 20, ISSUE Supplement 3, PAGES [S911 - S917]
REFERENCES
  1. Chenevert, M., et al., Shale Control with Balanced-Activity Oil-Continuous Muds, Journal of Petroleum Technology, 22 (1970), 10, pp. 1309-1316
  2. Gomar, M., et al., A Transient Fully Coupled Thermo-Poroelastic Finite Element Analysis of Wellbore Stability, Arabian Journal of Geosciences, 8 (2015), 6. pp. 1-11
  3. Mody, F., et al., Borehole-Stability Model to Couple the Mechanics and Chemistry of Drilling- Fluid/Shale Interactions, Journal of Petroleum Technology, 45 (1993), 11, pp. 1093-1101
  4. Heidug, W., et al., Hydration Swelling of Water-Absorbing Rocks: A Constitutive Model, International Journal for Numerical & Analytical Methods in Geomechanics, 20 (1996), 6, pp. 403-430
  5. Ma, T., et al., A Wellbore Stability Analysis Model with Chemical-Mechanical Coupling for Shale Gas Reservoirs, Journal of Natural Gas Science & Engineering, 26 (2015), Sep., pp. 72-98
  6. Ghassemi, A., et al., Linear Chemo-Poroelasticity for Swelling Shales: Theory and Application, Journal of Petroleum Science & Engineering, 38 (2003), 3, pp. 199-212
  7. Ghassemi, A., et al., Influence of Coupled Chemo-Poro-Thermoelastic Processes on Pore Pressure and Stress Distributions around a Wellbore in Swelling Shale, Journal of Petroleum Science & Engineering, 67 (2009), 1, pp. 57-64
  8. Zhou, X., et al., Finite Element Analysis of Coupled Chemo-Poro-Thermo-Mechanical Effects around a Wellbore in Swelling Shale, International Journal of Rock Mechanics & Mining Sciences, 46 (2009), 4, pp. 769-778
  9. Roshan, H., et al., A Fully Coupled Chemo-Poroelastic Analysis of Pore Pressure and Stress Distribution around a Wellbore in Water Active Rocks, Rock Mechanics & Rock Engineering, 44 (2011), 2, pp. 199-210
  10. Roshan, H., et al., Analysis of Pore Pressure and Stress Distribution around a Wellbore Drilled in Chemically Active Elastoplastic Formations, Rock Mechanics & Rock Engineering, 44 (2011), 5, pp. 541-552
  11. Wang, Q., et al., A Fluid-Solid-Chemistry Coupling Model for Shale Wellbore Stability, Petroleum Exploration & Development, 39 (2012), 4, pp. 508-513
  12. Sheng, J., et al., Analysis of Coupled Porothermoelastic Response of a Wellbore by Using a Femlabbased Simulator, Engineering Mechanics, 25 (2008), 2, pp. 219-223
  13. Jin, Y., et al., A Method for Determining the Critical Time of Wellbore Instability at Water-Sensitive Shale Formations, Petroleum Drilling Techniques, 32 (2004), 2, pp. 12-14
  14. Lu, Y.. et al., Influence of Porous Flow on Wellbore Stability for an Inclined Well with Weak Plane Formation, Petroleum Science & Technology, 31 (2013), 6, pp. 616-624
  15. Yuan, J., et al., Borehole Stability Analysis of Horizontal Drilling in Shale Gas Reservoirs, Rock Mechanics & Rock Engineering, 46 (2013), 5, pp. 1157-1164

© 2024 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence