عنوان مقاله [English]
Casing collapse is one of the costly and safety-threatening incidents in the oil industry. For example in Kupal oil field, Iran, approximately, a third of the wells have been removed from the production cycle due to casing collapse, which in some cases have led to the total loss of those wells. Since most of these cases have occurred in Gachsaran Formation, it is necessary to use an appropriate method to determine the geomechanical characteristics of this formation, especially, the layer considered as caprock for the underlain Asmari reservoir under the real conditions of temperature and pressure at real depths. In this paper, after discussing the effect of temperature, loading rate, and confining pressure on general geomechanical behavior of rocks, and in particular, the caprock of the Asmari reservoir, the results of geomechanical experiments performed under different temperature and pressure conditions on this type of rock are presented, and their comparison with the corresponding results determined by other researchers are discussed. The obtained results from the experiments demonstrate that under constant loading rate, each 1.0 MPA increase in confining pressure increases the strength of the caprock about 1.0 MPa. Conversely, every 1 °C increase in temperature decreases the caprock strength almost 0.2 MPa.
. Mehrgini B., Memarian H., Dusseault M. B., Ghavidel A. and Heydarzadeh M., “Geomechanical characteristics of common reservoir caprock in Iran (gachsaran formation), experimental and statistical analysis,” Journal of Natural Gas Science and Engineering, Vol. 34, pp. 898-907, 2016. ##
. Handin J. and Hager R. V., Jr., “Experimental deformation of sedimentary rocks under confining pressure: tests at room temperature on dry samples,” Am. Assoc. Petroleum Geologists Bull., Vol. 41, pp. 1–50, 1957. ##
. Heard H. C., “The influence of environment on the inelastic behavior of rocks,” Lawrence Radiation Laboratory, University of California, Livermore, California, 94550, 1969. ##
. Hokka M., Black J., Tkalich D., Fourmeau M., Kane A., Hoang N. H., Li C.C., Chen W.W. and Kuokkala V. T., “Effects of strain rate and confining pressure on the compressive behavior of Kuru granite,” International Journal of Impact Engineering, Vol. 91, pp. 183–193, 2016.##
. Liu Z., and Jin D., “Experimental research of rock strength and permeability characteristics under different confining and hydraulic pressure,” An Interdisciplinary Response to Mine Water Challenges - Sui, Sun & Wang (eds), China University of Mining and Technology Press, 2014.##
. Fjaer E., Holt R. M., Horsrud P. and Raaen A. M., “Petroleum related rock mechanics,” 2nd Edition, Elsevier, 2008.
. Mogi K., “Experimental rock mechanics,” Taylor & Francis, p. 361, 2007. ##
. Brady B. H. G. and Brown E. T., “Rock mechanics for underground mining,” 3rd edition, Kluwer Academic Publishers, 2005. ##
. Handin J. and Hager R. V., Jr., “Experimental deformation of sedimentary rocks under confining pressure: tests at high temperature,” Am. Assoc. Petroleum Geologists Bull. Vol. 42, pp. 2892-2934, 1958. ##
. Jackson M. P. A. and Hudec M. R., “Salt tectonics: principles and practice,” Cambridge University Press, 2017. ##
. Muller W. H., Schmid S. M. and Briegel U., “Deformation experiments on anhydrite rocks of different grain sizes: rheology and microfabric,” Tectonophysics, Vol. 78, pp. 527-543, 1981. ##