The Use of Expanding Grouting Cement for Separation of Layers at the Uzen Deposit

This paper presents a study on the effect of the content of expanding additives on the performance of grouting solutions, as well as experimental research on the impact of these additives on the strength of the hardened cement stone. Currently, targeted research is being conducted worldwide to increase the strength of cement stone in order to reduce its permeability, enhance the effective isolation of layers, and improve the adhesion of the cement stone to both the casing and the surrounding rock. In this regard, special attention is given to the development of high-strength grouting compositions to improve the sealing of the annular space in multilayer reservoir conditions. To address this issue, an expanding grouting mixture composed of 75% cold-well cement and 25% gypsum-alumina cement was used for zonal isolation. Expanding grouting cement containing calcium oxide was employed as an expanding additive during cementing. As a result of using this expanding grouting cement and its associated technology, 95% adhesion of the cement stone to the casing and formation was achieved. Considering these results and analyzing the multilayer structure of the Uzen field, as well as the need for effective isolation of permeable formations, it is proposed to cement the productive interval using expanding Portland cement.