Study On Downhole Gas/Water Separation Technique In Gas Wells

Downhole gas water separation (DGWS) technique, which offers both economical and environmental benefits, can greatly reduce the costs of lifting and treating of the produced water and extend the economic service lives of gas wells with high water cut by directly reinjecting the produced water into the formations of the identical gas wells. The separation efficiency and influential factors of downhole gas liquid separator were studied first in this paper using the computational fluent dynamics, mechanical model analysis and laboratory experiment methods. The design proposal of separator was then developed to provide reference criteria for optimizing structural and operational parameters. The guidelines of the selection of the DGWS production and reinjection scheme were given on the basis of the investigations. The whole system was divided into five subsystems and the flow behavior in each subsystem was studied separately. Designing model for the ESP-DGWS system was then established by using the nodal analysis method, which successfully solved the problem of selection criteria absence for the designing model of the system. A field application example was finally presented to illustrate the designing procedure. This study provided foundation for the candidate well selecting and system designing of the ESP-DGWS technique, and may promote the field application of this new technique.