Abstract
Steam injection wells are currently being exploited in the southern region of Mexico. These types of wells can present difficult challenges with respect to cementing operations. For example, the cement composition must be designed properly to withstand the extremely high downhole temperature induced by injected steam. Additionally, lost circulation should be minimized or prevented while cementing. It is also very important to help ensure effective mud removal and help prevent trapping fluids in the annulus, which might cause annular fluid expansion and casing collapse attributed to temperature changes during steam injection operations.
To overcome these challenges, combinations of optimized job procedures and technologies have been applied to wells under such significant conditions, demonstrating improved results. Temperatures the cement slurry encounters during and after placement are estimated using a simulator, which considers the heat transfer phenomena. Using a new generation of resin-based, nonmetallic centralizers attached to the casing has helped improve centralization. High performance thermal cements are the most suitable choices for cementing under these conditions. Displacement of mud has been enhanced using a state-of-the-art 3D simulator to help optimize rheological and density hierarchy.
Applications of these technologies have been successful, helping provide zonal isolation at production zones and helping minimize remedial work attributed to lost circulation. When evaluating cement bond logs (CBLs), the trouble zones present in the reservoir should be considered. These technologies can be applied using appropriate modifications for different global regions where similar challenges are encountered; additionally, they potentially provide cost-beneficial outcomes.
