The petroleum industry has recognized the problem of gas flow after cementing for more than two decades. Several laboratory investigations and field studies have been conducted in an attempt to solve the gas migration problem. However, most of the previous field practices designed to control the gas migration problem have been either unsuccessful or only partially successful. A study of the cause and a laboratory-developed solution for controlling the gas migration problem were presented in SPE 11207. The present paper summarizes the field results obtained during an eighteen-month period using an "impermeable cement" system to control the gas migration problem. Results of 84 cement jobs performed in Texas, Oklahoma, New Mexico and Louisiana are summarized, and unique field cases are discussed in detail. All four major types of cementing jobs have been performed using the "impermeable cement" system and an overall success ratio of over 90% was obtained.

No abstract