Modelling Production Initiation from a Lazy Well by Direct Gas Injection at the Casing Head Using Dynamic Wellbore Simulator

Abstract

This study deals with a lazy well completed with no packer in place. The main producing formation is showing strong signs of depletion where it lost more 2000 psig of reservoir pressure since the production started. Previous experiences in this well and other offset wells show there is demand for Nitrogen Injection Through Coiled Tubing Unit in the tubing in order to lift the well and bring it online whenever the well is shut-in for any reason. Direct natural gas injection at the casing head is a cost-effective alternative to rigless well lift operations. However, this is a challenging thing to achieve since it requires precise knowledge of injection rates and casing head pressure, additional to that formation fracture pressure and other reservoir characteristics should be taken into consideration. Data were collected and dynamic wellbore is created and linked to near well reservoir model to capture the transient behavior of the reservoir during start-up process. From Dynamic Modeling and simulation of the production system, best injection pressure, production choke, injection time and quantities are estimated and optimized for more efficient lifting process. After Initiating the well, production stability is observed in the transient simulator to ensure the success of the well lifting method. This method of production initiation is cost effective, and if implemented properly should bring the well back in production fast. Successful implementation this method demands a precise wellbore model to be created and shut-in surveys should be used to match the well status when it's not producing to tune the wellbore and fluid parameters.