Evaluation Method for Gas Kick Treatment Capability in Managed Pressure Drilling

Summary Managed pressure drilling (MPD) is a key technology for efficiently handling gas kick, and evaluating gas kick treatment capability is important to ensure the safety of MPD. Based on the gas/liquid two-phase flow state in the wellbore, considering factors such as gas dissolution and changes in physical parameters, a coupling model of wellbore temperature and pressure during gas kick control of MPD was established with an error within ±10%. A method for determining the gas kick treatment capability was established, considering the limitations of ground equipment and fracture pressure in leakage-prone layers. The numerical calculations revealed that an increase in the gas kick depth, mud density, and gas kick intensity reduced the gas kick treatment capacity. After the gas kick, the gas kick treatment capacity increased with an increase in the circulation pump rate and mud oil/water ratio. Based on the calculation results, a statistical model for the maximum gas kick treatment capacity and a quantitative risk matrix were constructed, forming an evaluation method for the gas kick treatment capacity of MPD. The calculation accuracy of this model is within ±20%. This method can quantitatively evaluate the gas kick treatment capacity and provide technical guidance for the design of on-site MPD plans.