Lessons Learned from Over 300 Producing Well Water Shut-off Gel Treatments

Abstract

ABSTRACT The economic lives of many wells are shortened due to the expense associated with handling excessive amounts of water production. Additionally, hydrocarbon production may be restricted as a result of high producing fluid levels that are commonly associated with high water production. Excessive water production in natural waterdrive producing wells usually results from either "coning" through matrix rock or from vertical fractures that extend into and conduct water from an underlying aquifer. Over the past eight years, Chromium III Carboxylate Polyacrylamide gels have been placed into more than 300 producing wells in such a way as to reduce water flow and lower fluid levels resulting many times with increased oil production due to improved drawdown. Typical water shut-off treatments reduce water production 75% to 90% and, depending on the formation and the cause of the water problem, oil production can be increased by as much as 1,000%. Gels have been applied to fractured and matrix permeability reservoirs, and to both carbonate and sandstone formations. This paper will focus on providing practical polymer gel information that, when used in conjunction with normal operations data, can be readily reduced to practice. Topics to be discussed include candidate selection criteria, job sizing, gel strength, treatment strategies, treatment monitoring and evaluation, risk factors, results and lessons learned. Economic data including project payout, cost per incremental barrel of oil produced and success rate will also be discussed. Case studies will be presented to demonstrate what is actually working in the field and what can be expected from a successful treatment.