Applying a Resin-Cement System to Help Prevent Fluid Migration in the Annulus: Case Study, Western Siberia

Abstract

Production sections of Western Siberian wells consist of gas, oil, and water-saturated sandstones; therefore, it is extremely important to help ensure zonal isolation to help prevent fluid migration from the overlaid water and gas formations into the oil-producing zones. Isolating the water and gas zones with conventional cement has not been a complete success because fluid migration was experienced through a channel or damage to the cement sheath. A typical solution sets an annular packer in the production casing zone beneath the gas and water-bearing sandstones as backup if the cement fails to provide a full annular barrier. Using the annular packer has some limitations, and potential risks of early activation or nonactivation of the annular packer often contributes to nonproductive time (NPT). An alternative solution used in Western Siberia combines resin-polymer and cement, which provides a cement sheath with improved mechanical properties, such as reduced permeability, increased ductility, and improved shear bond to casing. The successful use of a resin-polymer cement blend as an alternative to using an annular packer, advantages of using this system, and recommendations for implementing this technology are discussed.