Performance of Smart Cement with Nano-Clay Modification and Energy Treatment

Pertaining to recent reported failures of oil wells and increasing attention to safety and environmental issues, integrity of the cement sheath has been identified as the cause of these failures. Though oil well cement serves many purposes in the cemented oil wells, forming a sealing layer between the well casing and the geological formation in order to provide zonal isolation is the foremost. Real time monitoring of the performance of cement during the cementing and throughout entire life cycle of the well is a significant and complex step in an oil and gas drilling project. Currently, there is no technology available in the field to monitor cementing operations in real time. In recent researches, electrical resistivity has been considered as a monitoring parameter since it is a material property, which is sensitive to the changes inside the material such as hydration or crack formation. However, some modifications are needed since the electrical resistivity must be quantified to better interpret the change in the material. In this study, a series of experiments evaluated the cement behavior with and without modifications in order to identify the most reliable sensing properties. Smart oil well cement was modified with up to 1% (by weight of cement) of nano-sized clay materials (natural and synthetic) to investigate the change to the physical and compressive piezoresistive properties. The effect of external energy treatment on smart cement curing, hydration and compressive piezoresistive properties were studied with 1 Volt AC power supply with variable frequency. Damaged oil well cement was repaired using nano-clay solution and external energy treatment to understand its strength regain and self-sensing properties.Electrical and Computer Engineering, Department o