Abstract

Sand production is a prevalent problem during oil and gas production from weakly consolidated or unconsolidated formations. It can erode downhole equipment and surface facilities, cause pipeline blockage, leakage and damage casing and generate additional need for sand disposal. Decision for appropriate sand control strategy requires engineering analysis of the key parameters affecting sand production to evaluate timing and severity of sanding over the life of field conditions. This paper presents the effects of reservoir and geomechanical parameters including well trajectory, poroelastic stress coefficient, Biot’s factore, maximum horizontal stress, horizontal stress anisotropy ratio, cohesive strength and Uniaxial Compressive Strength (UCS) on sand production from openhole wells. The results indicated that the critical bottomhole flowing pressure increases with increasing the poroelastic stress coefficient, Biot’s factor, maximum horizontal stress and horizontal stress anisotropy ratio, but decreases with increasing the cohesive strength and UCS of rocks. Furthermore, the results show that the wellbore inclination and azimuth have a significant role in sanding potential during production. Also, it is concluded that in normal stress regime the critical bottom hole flowing pressure of a horizontal borehole is greater than the vertical borehole, so the vertical boreholes have less potential for sanding than the horizontal boreholes and almost all the deviated wells. Accurate prediction of the conditions for sand production is critical to the design of cost effective completion.

Key words: Sand production, geomechanical parameters, well trajectory, biot’s factor, horizontal stress.