A Successful High-Temperature Gel System To Reduce Steam Channeling

Abstract

AbstractA new high temperature gel system has been developed and successfully demonstrated in the field to reduce steam channeling and override in mature thermal projects. During the past three years a program has been underway in the laboratory and in several heavy oil fields in California, in an effort to develop a family of gels that can be injected in relatively small volumes (<600 barrels) into pre-existing steam channels and/or override sections within an active steam project. These inexpensive (< $15,000) gel treatments are applied with only a minimum amount of well downtime, typically three days, or less, and have demonstrated the ability to divert steam and increase oil recovery rates for up to a year and more. In addition to producing incremental oil, diversion of significant quantities of steam from existing thief zones has resulted in: (1) reduced volumes of live steam produced out casings, (2) reduced casing pressure, (3) a definite heat redistribution in the reservoir, (4) decreased flow line temperatures, (5) reduced well pulling and pump repair costs and (6) increased life in both injection wells and producing wells.This paper describes the typical treatments completed in four of California’s largest heavy oil fields and five different reservoir sand bodies. Data and discussions regarding the treatment methodology, monitoring tools and techniques, as well as the technical and economic evaluations are included. Despite the fact that many of the treatments were completed with heavy oil prices at, or near $10 per barrel more than 70% of the treatments were economic successes on incremental oil production alone. An example of one treatment is provided which produced more than 18,000 barrels of incremental oil in the first six months following the treatment.