الملخص الإنجليزي
In oil industry, the production of sand particles associated with the reservoir hydrocarbons becomes one of the most common problems a well may experience during reservoir lifetime. To prevent this problem, oil companies sometimes unnecessarily install sand control equipments without predicting or evaluating sand potential which in turn increases operating cost and decreases well productivity. Therefore, it is essential to predict under what production conditions (wellbore flowing pressure or production rate) sanding will occur and when sand control is needed.
This thesis presents a new 3D analytical model that can predict sanding onset from an openhole wellbores. The model estimates the critical wellbore pressure below which sand production is expected. Mogi-Coulomb failure criterion in conjunction with linear poroelastic constitutive model were utilized to develop the model. For vertical wellbore a closed-form solution is achieved. Another sanding stability model using the classical Mohr-Coulomb failure criterion was developed to point out on the impact of the intermediate principal stress on sand production prediction.
For non-vertical wellbore, a computer program in Mathcad was utilized to predict sanding onset pressure. The program has been modified to estimate sanding critical pressure during production. Analytical solution was then derived to obtain the optimal well path where the potential of sand production is minimized. To verify the models, real field cases from published literature and an Omani oil field have been simulated. The model generated results that compare well with the actual field observations.
The developed model allows petroleum engineers to predict sanding onset pressure from openhole wellbores to come up with the optimal field development plan and well completion design. It can also be utilized for cased and perforated wells as an approximation tool.
