عنوان مقاله [English]
In this paper, the properties of a new formulation for manufacturing and production of class G cement has been proposed. The produced industry cements have no proper rheological properties, thickening time and compressive strength. This paper investigates the effects of particle size distribution changes as a basic parameter on the principal properties of cements such as rheological properties, compressive strength, thickening time and also compatibility of designed cement with certain additives used in oilwell cements formulation such as retarders and fluid loss control. The designed cement is non-uniform and coarser than conventional cements which 50 percent of particles are in the range of 3-30 µm where this amount is more than 70 percent for other standard class G cements. The designed cement has very good rheological properties and requires lesser energy for production and more compressive strength will be obtained due to 10 percent decrease in the amount of water usage in the cement system. Since the use of additional additives leads to more cost, the proposed cement designed in a way that a heavy cement will be obtained without using weighting agents.
. Bensted J., Shaunak R., “Early hydration of class G oilwell cement”, Proc. 11th Int. conf. Cem. Microsc., New Orleans, pp. 198-224, 1989.
. Lota J. S., Bensted J. and Pratt P. L., “Characterisation of an unhydrated class G oilwell cement”, L’ Industrial Italiana del Cementom, No. 729, pp. 172-183, 1998.
. Bentz D. P., Garboezi E. J., Haecker C. J. and Jensen O. M., “Effects of cement particle size distribution on performance properties of Portland cement based materials”, Journal of Cement and Concrete Research, vol. 29, pp. 1663-1671, 1999.
. Celick I. B., “The effects of particle size distribution and surface area upon cement strength development”, Journal of Powder Technology, Vol. 188, pp. 272-276, 2009.
. Bye G. C., Portland cement: composition, production and properties, Pergamon Press, UK, 1999.
 Tsivilis S., Tsimas S., Benetatou E. and Haniotakis E., “Study on the contribution of the fineness on cement strength”, ZKG 1, pp. 26-29, 1990.
. Sprung S., Kuhlmann K. and Ellerbrock H. G., “Particle size distribution and properties of cement”, Part 1: strength of Poetland cement, ZKG 6, pp. 136-145, 1985.
. Ellerbrock H. G., Sprung S. and Kuhlmann K., “Particle size distribution and properties of cement”, Part 3: Influence of grinding process, ZKG 3, pp. 275-281, 1990.
. Sprung S., Kuhlmann K. and Ellerbrock H. G., “Particle size distribution and properties of cement”, Part 2: Water demand of portland cement, ZKG 9, pp. 275-281, 1985.
. Lawrence C. D., “The constitution and specifications of Portland cements”, in: C. Hewlett Peter (Ed.), Lea’s Chemistry of Cement and Concrete”, Fourth Edition, John Wiley&Sons, New York, pp. 131-188, 1998.
. American Petroleum Institute, Specification for materials and testing for well cements' APl specification 10A, American Petroleum lnstitute,Washington D.C., 1995.