Paper: Methods of Improved Selectivity and Control in Well Stimulation

The necessity and desirability of well stimulation has been apparent for many years. Many wells and fields would not be economical producers without modern completion and stimulation methods. To break this situation down even further, it can be said that where several porous zones are present in a well, each zone will not contribute its maximum production without proper treatment. With these things in mind, our purpose becomes very clear. It is simply to properly stimulate each porous zone or stringer in the pay section. A number of methods have been employed to achieve this selectivity. Among these are packers, bridging plugs, straddle packers, and various forms of gels and other blocking materials. Tubing and packer methods are accompanied by reduced injection rates. Bridge plug methods require more time. Gel and blocking material methods are difficult to evaluate. Any of these approaches to selectivity involve considerable expense.