Henry Lopez and George Woo, BJ Services Company, USA,
Charlie HofJI Pioneer Natural Resources
Historically, tight gas formations such as the Strawn limestone in Crockett County, Texas and the Devonian in Andrews and Midland Counties, Texas have been treated with pad and acid treatments consisting of gelled water, gelled acid and
crosslinked hydrochloric acid. A new emulsion polymer has been developed which significantly increases the efficiency of these treatments. The new emulsion polymer exhibits a polymer size approximately 15 times smaller than that previously known to the industry. The polymer also utilizes a highly specific external activator to initiate and promote hydration. This process allows the microsized polymer to effectively disperse prior to hydration, thereby dramatically reducing the potential to form un-hydrated masses ("lumps" or "fisheyes"). Both macro and microscopic "lumps" can be particularly detrimental to the formation matrix. This paper will document the increased well production of the &awn formation in Crockett County, Texas and the
Devonian formation in Andrews and Midland Counties, Texas as a result of the polymer's use, outline the treatment, and describe the chemistry of the new emulsion polymer and its operational efficiency and versatility.