SUMMARY:

The major heavy oil production technology is Cold Heavy Oil Production with Sand (CHOPS). This is a single well technology, which involves the deliberate initiation and sustaining of sand inflow into the wells using progressive cavity pumps (PCP) to produce at oil high rates with a subsequent high-pressure drawdown around the wellbore. This production strategy of aggressive and continuous sand production enhances noticeably the oil recovery. CHOPS as recovery process has important challenges and high complexity because it responds to two main mechanisms such as the foamy oil and the wormhole formation, both consequences of complex geomechanical aspects as the in situ stresses redistribution, the elastoplastic behavior and the sand liquefaction. The enough components for a 3D single well numerical model for cold heavy oil production with sand are proposed coupling two main elements: a reservoir or fluid flow component and an elastoplastic geomechanical or stress - strain component. The fluid flow component is a multiphase fluid (three phases) composed by oil, gas and water using equations in cylindrical coordinates because this geometry fits the behavior of the flow in the region around the well, where the elastoplastic deformation occurs. The elastoplastic component includes four elements: an incremental stress - strain relation, a yield surface, a flow rule and a hardening / softening law. In addition, a sand production module is also included by the integration of two primary elements: a sanding onset to determine when is obtained the initiation condition for sand production and a sand production criterion to quantify the produced sand. Also, two more components are required to adjust and match a CHOPS model: a foamy oil module to involve the entrained gas drive mechanism from foamy oil crudes and the wormhole module to include the formation and propagation of void space generated by the massive sand production. CHOPS is a newfangled and cost effective alternative to the exploitation of heavy oil reservoirs around the world and especially in Latin America. Modeling cold heavy oil production with sand will lead to understand the complexity of the cold production process and will help also to evaluate how to increase the recovery factor under geomechanical stability conditions and to reduce operational costs of heavy oil reservoirs producing by this technology.

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