An quantitative evaluation method for gas channeling in the process of gas injection development of condensate gas reservoirs and its application

When cyclic gas injection is conducted in a condensate gas reservoir, the injected dry gas tends to break through along high-permeability pathways or natural fractures due to reservoir heterogeneity, and consequently its development effect is impacted. To improve the development effect and increase the hydrocarbon recovery factor, it is of great significance to investigate the gas channeling characteristics of injected gas in condensate gas reservoirs and establish the gas channeling identification and evaluation system for the injected gas in condensate gas reservoirs. At present, the gas channeling discrimination methods for condensate gas wells at home and abroad include field experience method, chart method, tracer method, microseismic monitoring method and so on. Based on the variation characteristics of gas channeling parameters during the production of condensate gas reservoir by the cyclic gas injection, the gas channeling was evaluated using above methods comprehensively, and the quantitative evaluation system for the gas channeling of injected gas in condensate gas reservoirs was established. Then, one actual well in a certain condensate gas reservoir was taken as the example and its gas channeling was evaluated. It is indicated that this well is in good production condition without gas channeling. The evaluation result is consistent with the actual field situation. The quantitative evaluation system for the gas channeling of injected gas in this condensate gas reservoir provides the theoretical basis for development deployment, optimization and gas channeling control of condensate gas reservoirs.