Geomechanics and Geoenergy Journal

Geomechanics and Geoenergy Journal

Prediction of Sand Production-Prone Zones and Determination of Critical Drawdown Pressure Using a One-Dimensional Geomechanical Model in the Asmari Formation

Document Type : Original Article

Authors
1 M.Sc. Student in Petroleum Production Engineering, Faculty of Chemical, Petroleum and Gas Engineering, Shiraz University
2 Faculty of Chemical, Petroleum and Gas Engineering, Shiraz University, Shiraz
Abstract
Sand production is a core challenge in oil and gas, occurring when sand accompanies oil and water production, damaging equipment and reducing well productivity. To mitigate sand production, building a geomechanical model of the formation is essential. This study evaluates sand production potential in the Asmari Formation using a 1D geomechanical model. To accurately determine rock geomechanical parameters, Techlog, along with well logs and core data, was used. After finalizing the geomechanical model and validating it with laboratory results, the proelastic method predicted effective zones, calculated the critical drawdown pressure (CDDP), and forecasted the onset time for sand production. The impact of different completion types on the CDDP was also examined. Results indicate that a perforated completion best mitigates sand production and can serve as a control strategy to reduce its potential. Findings show a high likelihood of sand production at 2357 meters depth, since CDDP is negative, signaling a strong rock-failure potential at this depth. A sensitivity analysis considered ranges of UCS, sand grain size, wellbore diameter, azimuth angle, well deviation, and perforation angle and diameter. These parameters are critical for real-time decisions on control techniques. The study focused on geomechanical sensitivity; hydromechanical fluid parameters were not included in the modeling, and the software used cannot define fluid behavior. By centering on the Asmari Formation and using a calibrated one-dimensional geomechanical model with actual lab data, the work offers a new perspective for more accurate sand production predictions in similar reservoirs. Precisely identifying critical sand-production zones at 2357 meters, based on the overlap of geomechanical data and predicted CDDP helps delineate high-risk regions for optimal completion design. Additionally, sand production behavior in vertical, deviated, and horizontal wells was analyzed and compared for perforated versus open-hole cases, to assess how well type influences formation stability and overall sand-risk.
Keywords