| With the continued growth of petroleum demand, the oil and gas companies are searching in new or unexplored areas. The search is getting extreme in terms of depth, temperature and pressure. In deeper wells, high temperature and pressure and post cementing operations put extreme stresses on the cement sheath and affect the integrity of the cement. In such conditions, the design of cement slurry is very critical and it must possess properties which ensure the durability and long term integrity of cement sheath. To resolve this problem, many additives are being investigated and used in high pressure and temperature wells.;Recently, Nano Materials have demonstrated effectiveness across a wide variety of industries, from textiles and defense to aerospace and energy. They are now being used as commercially worthwhile solutions to technical challenges faced many industries. Having high surface area and small size, attracts them to petroleum industry. Their application in petroleum industry is progressing in a last few years.;The objective of this study is to evaluate the physical properties of Saudi cement class G with Nano clay addition and admixed with different additives such as fluid loss agent, retarder, expanding agent and friction reducing agent under high temperature and pressure conditions. Nano clay is added at different percentages to the cement slurry mixture currently used for oil/gas well cementing in Saudi Arabia. Experimental investigations addresses different cement slurry properties such as thickening time, free water separation, rheological properties, compressive strength, density, porosity, permeability, and SEM and XRD analysis.;The best slurry design is selected on the basis of results of different percentages of Nano clay used in experiments. From the laboratory tests, it is investigated that addition of Nano clay improves the rheological and mechanical properties, reduces the free water contents, retards the thickening time, reduces the density, makes the strong microstructure of cement and helps in designing the new cement system which sustains the high pressure and temperature conditions and gives good results. This new cement design can be prepared and implemented in the field without adverse effects. |
