Abstract

Controlling damage from sand production in hydrocarbon-producing wells demands substantial capital investment. Therefore, our research focuses on sand-production tendency using geomechanical studies of sandstone cores to evaluate perforation stability. Eight samples of well sorted and uniform coarse-grained (CG) and fine-grained (FG) sandstone underwent uniaxial and triaxial tests for mechanical rock properties. Principal stresses at depth were chosen for three faulting regimes (i.e., normal, normal to strike-slip, strike-slip) and identical rock mechanical properties were considered at all depths. Safe minimum bottomhole flowing pressures (SMPwf) for sand production onset and critical drawdown pressures (CDP) were calculated. Results indicate that at near-surface depths, perforating in either SHmax (maximum horizontal stress) or Shmin (minimum horizontal stress) direction will not result in sand production at high drawdowns (SMPwf < 0 for all samples). However, at depths > 1 km, the situation varies depending on the production drawdown, perforation orientation, and faulting regime. SMPwf is > 20 MPa at 2 km depth for most, if not all, cases. Perforation stability at depth is marginally to considerably higher (0-50 MPa difference in SMPwf) when created in the SHmax, as opposed to Shmin direction. CG samples may witness the onset of sand production earlier than the FG samples due to their higher uniaxial compressive strengths (FG_UCS: 25.5 vs CG_UCS: 11.5 MPa). In all cases, for a given rock strength, sand production tendencies increase with perforation depth due to higher overburden and tectonic stresses. These observations assist operators in understanding sand production tendencies from rocks of similar mechanical properties located at various depths.