Paper: WATER SHUT-OFF TREATMENTS USING AN ORGANICALLY CROSSLINKED POLYMER SYSTEM IN MEXICO

This paper presents the application of an organically crosslinked polymer system (OCP), a system widely used in the oil industry for water shutoff applications. The OCP system is based on a copolymer of acrylamide and t-butyl acrylate (PAtBA) crosslinked with polyethyleneimine (PEI). To date, more than 300 jobs have been performed worldwide and at least about 100 jobs have been done in Mexico with this system to address conformance problems such as: water coning/cresting, high-permeability streaks, gravel pack isolation, fracture shutoff, and casing leak repair. An overview of case histories which utilized OCP in various regions of Mexico is presented for a wide variety of applications. Particularly, a case history of an offshore well treated with the OCP is presented. A direct comparison of the application of the OCP with conventional cement squeeze treatment is presented to illustrate the advantage of having a deep matrix penetration for a more efficient water shutoff. In addition, data presented in this paper indicates the development of a retarder that allows the upper placement temperature of the OCP system to be raised to at least 350_F. The upper placement temperature of the system originally was ~260_F.