ANALYSIS OF PROPERTIES CHANGE OF CEMENT SLURRY AND STONE UNDER FORMATION IN FROZEN ROCKS
Zimina D.A. – postgraduate student of Saint-Petersburg Mining University, ziminadar@yandex.ru ziminadar@yandex.ru
Dvoynikov M.V. – Doctor of Technical Sciences, Professor, Head of the Department of Well Drilling, St. Petersburg Mining University, dvoinik72@gmail.com dvoinik72@gmail.com
Polyansky S.D. – student of Saint-Petersburg mining university, boamundusrex@gmail.com boamundusrex@gmail.com
УДК 622.245.422
Key words: well casing, cement stone, cementing slurry, microsilica, cement stone strength, porosity, low and negative temperatures, permafrost, thermal field.
It is known that in the permafrost zone, the low interval temperature significantly affects the quality of well casing and can lead to troubles such as thawing of rocks, their refreezing, small cement stone adhesion, and others. Therefore, when choosing the composition of the cement slurry for cementing in the permafrost zone, it is necessary to take into account both technological and thermophysical properties. This paper presents brief information about the conditions for the formation of cementing slurry and cement stone in the range of frozen rocks. The results of a computational experiment to determine the temperature distribution as a function of time taking into account the temperatures of the cementing slurry and displacement fluid are presented. The results of experiments to identify the dependence of changes in the structure of stone on the temperature distribution show that on the side of the heated surface of the cement stone, the porosity decrease, which ensures a decrease in the gas permeability of the well. It is established that the regulation of the structure of the stone in the zone of frozen rocks during its formation under the conditions of alternative thermal fields is possible by using the setting time regulators and microsilica as additives in the mixing fluid.
ANALYSIS OF PROPERTIES CHANGE OF CEMENT SLURRY AND STONE UNDER FORMATION IN FROZEN ROCKS
Zimina D.A. – postgraduate student of Saint-Petersburg Mining University, ziminadar@yandex.ru
Dvoinikov M.V. – Doctor of Technical Sciences, Professor, Head of the Department of Well Drilling, Saint-Petersburg Mining University, dvoinik72@gmail.com
Polyansky S.D. – student of Saint-Petersburg mining university, boamundusrex@gmail.com
Key words: well casing, cement stone, cementing slurry, microsilica, cement stone strength, porosity, low and negative temperatures, permafrost, thermal field.
It is known that in the permafrost zone, the low interval temperature significantly affects the quality of well casing and can lead to troubles such as thawing of rocks, their refreezing, small cement stone adhesion, and others. Therefore, when choosing the composition of the cement slurry for cementing in the permafrost zone, it is necessary to take into account both technological and thermophysical properties. This paper presents brief information about the conditions for the formation of cementing slurry and cement stone in the range of frozen rocks. The results of a computational experiment to determine the temperature distribution as a function of time taking into account the temperatures of the cementing slurry and displacement fluid are presented. The results of experiments to identify the dependence of changes in the structure of stone on the temperature distribution show that on the side of the heated surface of the cement stone, the porosity decrease, which ensures a decrease in the gas permeability of the well. It is established that the regulation of the structure of the stone in the zone of frozen rocks during its formation under the conditions of alternative thermal fields is possible by using the setting time regulators and microsilica as additives in the mixing fluid.
