More Than 12 Years of Experience with a Successful Conformance-Control Polymer Gel Technology

Abstract

Abstract In this paper, we discuss and describe our extensive exper-ience with the widely applied and quite successful Cr(III)-carboxylate/acrylamide-polymer (CC/AP) gel technology for use in oilfield conformance-control, sweep-improvement, and fluid-shutoff treatments, along with briefly reviewing the gel technology's development. Chromic triacetate is the often-preferred chemical crosslinking agent used in conjunction with this polymer-gel technology. The CC/AP gel technology, which was conceived in late 1984, is characterized as having a robust gel chemistry and as being highly insensitive to petroleum reservoir environments and interferences. This gel technology has been employed in over 1,400 conformance-control treatments worldwide. Highlights of illustrative field applications and results involving the CC/AP conformance-control gel technology are presented. An overview of what a decade-plus of experience in developing and applying the CC/AP gel technology has taught us is discussed. This includes discussion of: classifying and distinguishing conformance problems and treatments, attributes of good candidate wells and well patterns for gel conformance-control treatments, requirements that must be met in candidate wells and well patterns in order to achieve success, gel treatment elements that must be successfully implemented in order to achieve success, guidelines where conformance polymer-gel treatments are most successfully applied, risks and pitfalls of gel conformance treatments, and quality control issues. Introduction The development and application of effective conformance-control treatments have been, until somewhat recently, elusive goals within the oil industry. Broadly speaking, conformance-control treatments include both treatments to improve volumetric sweep efficiency during oil-recovery flooding operations and treatments to reduce excessive and unproductive co-production with oil of such fluids as water and gas. That is, the co-production of other fluids that compete with the production of oil. Conformance-control treatments have at times been referred to, in an overly narrow fashion, as profile-modification treatments. Polymer gels of conformance treatments act as permeability-reducing agents and, as such, act as blocking and plugging agents. The gels of such treatments operate by reducing the fluid-flow capacity within the treated portion of the reservoir.