As the global demand for energy increases, operators are being forced to drill in increasingly challenging environments. Drilling through highly depleted zones and weaker formations requires low-density cements that are pushing the limits of current technology. If the cement is made light enough to circulate, but cannot withstand downhole conditions the initial seal will only be temporary. If cement cannot be successfully circulated or fails to function shortly after placement, this can have a large impact on the drilling cost and can cause delays in production delivery due to the required remedial work. If damage is too severe, remedial work may not be enough to protect the integrity of the casing or effectively isolate the downhole formations resulting in a complete loss of the well.
Previously the industry has demonstrated the ability to both successfully circulate ultra-lightweight cement and to provide a cement that could withstand the 550°F steam environment similar to what is present in the Kuwait application, but never in the same well. This newly developed slurry design capable of circulating past these weak formations, maintaining its seal under these temperatures, and surviving chemical attack from moist CO2 (which is often present under steam injection conditions), is unique in the industry allowing the operator to proceed with plans to effectively produce their reservoir.
Slurry development including testing procedures and results will be presented. Discussion of well design, reasons for steam injection, the method for delivery of the slurry, and actual case histories will be provided.