Quantitative Description Of Steam Channeling During Multi-Cycle Cyclic Steam Stimulation

During cyclic steam stimulation(CSS)in heavy oil reservoirs,steam channeling is easy to form in the formation.The steam channels in the formation are the dominant channels for fluid flow.Injected steam directly flows into the production well through these channels,which tremendously reduces the thermal efficiency of steam and affects the development of heavy oil reservoirs.Previous studies only achieved qualitative analysis of steam channels,while there have been few studies on quantitative calculation of physical parameters of steam channels.This paper will systematically study the quantitative description method of steam channeling between wells during CSS,including the analysis of the formation and evolution of steam channels through two-dimensional visual physical experiments,which enables us to observe the geometry of steam channeling;then,a theoretical model of wedge-shaped steam heating range is proposed,and energy conservation equations are established to calculate the steam heating range before steam channeling;the calculation method of absolute permeability of steam channeling formation is established based on the high-speed non-Darcy seepage formula;and a theoretical formula for calculating the diameter and number of steam channels are established based on the tube flow formula;a comprehensive evaluation method for the development degree of steam channels is proposed by considering the injection and production parameters;The quantitative description of the research results has been applied to practical oilfields.The verification results show that the quantitative description method of steam channeling proposed in this paper can accurately calculate the physical parameters,geometric parameters and development degree of steam channels.