Control of Cement Slurry Formulation for an Oil Well in a Critical Geological Layer

Abstract

In this study we were interested in the cementing of 9″ 5/8 casing corresponding to 12″ ¼ drilling section from an oil well drilled in the field of Hassi Messaoud in southern Algeria. This section is located in a very critical geological layer called LD2 (Horizon B), which is characterized by the production of calcic chloride waters that are very aggressive and virulent. Therefore the complexity of the geological formation encountered when drilling implies the need for a very precise pumping process to check pore pressure and the venus. This constraint has been imposed in high density work to avoid the dilution of cement slurry by chloride calcic waters. As a consequence, particular attention must be given to the proper control of the properties of cement slurry such as adequate rheology in order to achieve the target of obtaining a sustainable cement sheath. The cement type is of great importance in performance. Here we used a mixture of salt-saturated water with some basic additives and a combination of three materials: Dyckerhoof cement class G blended with the silica flour and hematite powder as a powerful additive to maintain the density of the slurry.