Well Architecture: Prediction of the Life Cycle Critical Drawdown Offered by Means of Passive Sand Control

Most Geomechanical studies detail the conditions of which a given reservoir will fail given the stress states and rock strength. A full study usually involves rock mechanic tests, verification of in situ stresses, and the calibration of logs to produce a mechanical earth model. The result of these studies is usually the critical drawdown and bottomhole pressures at current and future depleted pressures. There is, however, no published method on how to evaluate the value of sand control in a given field development. This issue can become a hindrance when it comes to finalizing or justifying a particular AFE budget. A method is formulated where the critical bottomhole flowing pressure is determined from a verified sand failure criterion. An abandonment pressure is predetermined, and material balance calculations are done for every fixed pressure drop. The inflow performance relationship is developed from deterministic parameters, and adjusted to well test results. A critical flowing rate is then inferred from the critical flowing bottomhole pressure. Pressure conditions where the sand fails results in a critical flowing rate of zero. The cumulative production and producing duration can then be determined. This method can be programmed in a computer spreadsheet as iterations are required for the numerical determination of critical drawdown and material balance calculations. The dynamic coupling between sand failure prediction, inflow performance, and material balance calculation enables the life cycle evaluation of passive sand control. This paper provides a general guideline of optimizing EUR and the producing duration by minimizing sand production risk through optimized well trajectory, perforation orientation, selective perforation, and sand face completion design.