Abstract
There is increasing emphasis on enhancing production and extending economic life of mature fields, especially including waterflood operations, globally. With that, it stands to reason that greater focus should be placed on controlling production of unwanted water relative to oil and gas production, as well as on improving the utilization of the large volumes of water to optimize waterflood sweep efficiency.
Mechanical and chemical treatment methods for shutting off or at least controlling, unwanted water production have existed for many years. Technologies and methods continue to evolve, albeit slowly. The same is true for injection well treatments for profile modification and improved oil reservoir sweep efficiency purposes. In the family of chemical treatments confined to production wells for controlling water rate are the so-called relative permeability modifiers (RPMs). Despite the long-standing (and continuing) skepticism of RPMs, in general, their implementation has increased in recent years – including uses in conjunction with oil and gas well stimulation treatments. Certainly, some of the criticism of RPMs is justified as they are often misapplied beyond their realistic physical and chemical capabilities. However, the creative application of RPM chemistry in production enhancement applications and in waterflood operations should not be generally dismissed or discouraged.
This paper discusses creative uses of RPM systems with properties conducive to application in both matrix and naturally-fractured sandstones and carbonates. Such applications include using RPM systems in hydraulic fracturing, acidizing, scale removal and inhibition, salt block inhibition, and waterflood injection profile modification. Both conceptual and field-proven applications are included. Results of laboratory studies and field case examples are presented.
