Abstract
As the world's demand for natural gas hits new records, technology developers and researchers work interactively to provide new technologies that support gas production and supply. Among these technologies come isolation plugs: mechanical and chemical. Chemical plugs have two main advantages over mechanical plugs. First, chemical plugs enable more flexible movement for Coiled Tubing (CT). Second, chemical plugs are easier to remove once unneeded using acid.
Fluid systems used as diverters and temporary plugs in stimulation and work-over operations, are mostly polymer-based fluids that generate less damage to the formation and can hold higher differential pressures. The use of this technique has minimized the need for mechanical packers, bridge plugs and mechanical diversion techniques.
One application for chemical plugs is selective zonal stimulation, where a coiled tubing and chemical plug are used in multi¬zone gas wells to selectively stimulate zones of interest. This paper outlines the first, in Saudi Arabia Gas Fields, successful deployment of a chemical plug— using CT — to stimulate the lower interval while isolating the upper producing interval. In addition, the plug's key characteristics, optimum rate and amount are addressed.
Analysis of the post-treatment results, production rate and flowing wellhead pressure, demonstrated a very positive productivity.
