Packing compactness of cementing slurry system for close packing optimization

Close packing technology, as the key technology for the design of high-performance cementing slurry system, is of great significance to improve the performance of cementing slurry, and its core is to increase the packing compactness of grain system.The compressible packing model was taken as the theoretical model of close packing, and model parameters and numerical calculation methods were ascertained.Calculation program of packing compactness was worked out and its calculation results were verified.The factors influencing the packing compactness of grain system were analyzed by calculating the packing compactness of multi-grain system.Finally, slurry was design and its performance was tested.It is indicated that the packing compactness can be improved effectively by adding ultrafine grain compositions moderately, optimizing size distribution interval appropriately and increasing average diameters of large and small grains in the grain system.Compared with ternary system, quinary system with nano materials has the closest packing of grain system and presents better slurry performance.It is feasible to take the close packing model as the guide for the design of dry mixing ratio of cement system used in oil wells.