Analytical models for sand onset under field conditions

• Published in: Journal of petroleum science & engineering Vol. 172; pp. 171 - 189
• Main Authors: Papamichos, E., Furui, K.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-01-2019
• Subjects: Anisotropic stresses; Field applications; Finite element method; Hole failure models; Sand production; Finite element method; Anisotropic stresses; Sand production; Field applications; Hole failure models
• ISSN: 0920-4105; 1873-4715
• DOI: 10.1016/j.petrol.2018.09.009

Analytical sand onset models consider the tangential stress at the hole (wellbore or perforation) to compare with the strength of the formation. This simplified criterion does not consider the effect of axial and shear stress at the hole which in experiments have been shown to play a role. This paper presents the formulation of three analytical failure criteria for wellbore or perforation failure and sand onset under field conditions. The resulting analytical expressions are suitable for implementation in programs for sand onset and sand mass analyses. Expressions for critical formation strength, critical drawdown or critical depletion for sand onset are derived. The models can be calibrated on hollow cylinder hole failure strength data or eventually on the uniaxial compressive strength. The analytical model results are compared and validated on numerical simulations using a finite element program developed for sand production studies. The comparisons show that analytical models can reproduce satisfactory sand failure diagrams under various stress anisotropy and production conditions in the field. Finally, the effect of the wellbore on the perforation stresses is analyzed by comparing finite element and analytical results.
•Sand onset models for field applications capture in situ stress anisotropy.•Analytical sand onset model replicates experimental and numerical results.•Model calibration on hollow cylinder tests under isotropic and anisotropic conditions.•Formulation amenable for analytical sand onset and sand rate prediction programs.