ABSTRACT
The Appalachian Basin presents one of the most challenging production and stimulation problems because of the iron content of its hydrocarbon producing formations.
A variety of iron compounds in the producing formations present problems that have to be considered to effectively stimulate these formations. These iron compounds present three major problems:
Relatively insoluble iron compounds that may be released by acidizing fluids and have a plugging effect when they migrate;
Acid soluble iron compounds that may reprecipitate when the acid spends; and
Aerated fracturing fluids being incompatible with formation waters that contain ferrous iron.
A research program was initiated in the later part of 1980 to determine methods of more effectively controlling the iron problems in the Appalachian Basin. Results of this study provide data for comparing the effectiveness of various iron control systems that are used in acid stimulation or breakdown techniques that minimize the release of acid insoluble solids and stabilizes them to decrease the detrimental effect caused by fines migration. Also developed in this study was an iron control system that helps the compatibility of the treating fluid with ferrous iron in the formation water.
Flow test data and field results indicate the effectiveness of these iron control systems and treating techniques.