Experimental investigation of mixing energy of well cements: The gap between laboratory and field mixing

Abstract

Previous research on cement mixing energy for oil and gas applications shows dual importance of mixing energy and shear rate. The mixing conditions of the slurry and its mixing energy strongly impact the behavior of slurry. Generally, cement slurries are designed to perfection in the laboratory, however developing similar properties in the field operation is challenging. It is common that the properties of cement slurry obtained from laboratory and field mixing do not correlate very well, which can lead to different cement-job problems. The primary objective in this paper is to show whether matching mixing energy will result in similar properties in cement. In this study, a comparison of cement properties such as cement strength (UCS) and rheology and thickening time are compared with properties of same cement slurries prepared and mixed using yard mixer. Samples prepared in laboratory were mixed according to API (American Petroleum Institute) standards. Our results show that measured properties are different when mixed in the laboratory and yard conditions. Some of the properties such as UCS and rheology demonstrate a strong deviation by changing mixing conditions.