Research On The Reasonable Gas Injection Parameters Of The Counter-circulation Drilling

Gas lift counter-circulation well drilling mainly be used in resolving low voltage leakage easy stratigraphic drilling. Based on the Gas lift counter-circulation well drilling, drilling fluid flow characteristics, fluid dynamics, non-Newtonian fluid mechanics and flow around the sphere based on the theory for gas lift counter-circulation drilling, drilling fluid produced during the initial flows to the initial gas injection pressure and to meet the drillstring in the drilling fluid carrying dust, bottom purification reasonable flow of gas injection conditions for conducting a comprehensive analysis and research. The establishment of a drilling fluid in the drillstring, and the annular space axial-flow model; established a mobile Starter liquid gas injection pressure conditions equation; analysis and research within the drillstring drilling fluid carrying litter laws and bottom of - purification mechanism, the establishment of a drilling fluid carrying debris to the bottom-speed computing model and purification role model; determine a reasonable implementation of reverse circulation drilling the initial gas injection, gas flow rate, as well as from the beginning to reverse circulation gas injection flow of time the establishment of the wellbore multiphase flow model; identified any point within the wellbore phase fluid flow and to meet the bottom of the drillstring purification and decontamination requirements of the injection flow velocity; cycle for the implementation of anti-scientific drilling technology to provide a theoretical basis .