Study of channeling problem in cementing oil wells in long sections

Abstract

The process of cementing the well is one of the most important stages that the driller must perform to the fullest extent, as the cement works to stop and isolate the expected leaks resulting from the formation, especially the leakage of gas, which is considered a severe problem in the drilling field, as it seizes the opportunity to cross during the dryness of the cement (from the case liquid to solid) which results in a drop in well pressure to form transit channels towards the surface called channeling. Hydrostatic pressure being less than pore pressure and the existence of a path to gas migration are two major factors that must be stopped simultaneously to prevent migration. On the other hand, Understanding the mechanisms of cement hydration in early times is necessary to investigate these factors. It can lead to swelling and shrinkage at the same time. At the beginning of cementation chemical shrinkage occurs, followed by swelling and autogenously shrinkage. The most important factors that make the annulus pressure less than the pore pressure are: cement placement, Cement hydration in liquid state, and Cement hydration in solid-liquid state In our topic, we dealt with the problem of gas migration in the Ain Saleh area, where we touched on a new technique used recently called Flex Stone which is a substance that reduces gas permeability in cement to be the most effective method for this event.