A Quantification of Mixing Energy During the Whole Cementing Cycle

Various authors have pointed out the importance of cement mixing process and its effect on cement properties. From all cement properties, two are extremely important: the mechanical cement strength (unconfined compressive strength or UCS) and the rheology. The first is critically impacting the well integrity whereas the latter is affecting the pumping ability and displacement in the well, which will also have effects on the well integrity. A previously performed literature survey has pointed out that mixing energy alone may not be sufficient to describe the cement slurry changes, and inferred that shear rate can also impact the final cement properties, such as thickening time or cement strength. Starting from the existing investigations, our goal is to quantify the source of maximum energy input during a conventional cement job and estimate its effect on final cement properties. This paper is showing theoretical and experimental investigations on selected API cements with respect to their properties as a function of mixing energy. The first part of the paper is focusing on the estimation of mixing energy in different section of the cement pathway to the annulus. The second part will show some experimental results and the new way ahead, based on our findings.