Comparison of Elastic Modulus between Class G Cement and Geopolymer Cement under HPHT Condition

Well cementing is one of the important systems in oil and gas drilling. It provides support and protection to the casing, prevent the movement of fluid through the annular space outside the casing; stop the movement of fluid into vugular or fractured formations and it also use to close an abandoned well. However, Ordinary Portland Cement (OPC) used are having issues with its strength since it take a long period of time to develop and lots of rig time losses for waiting on the OPC to set. This project introduced geopolymer cement as an alternative for Class G cement. It aims to compare the elastic modulus of both Class G cement and geopolymer cement. Cement samples are prepared which consist of basic case Class G cement and a mixture of fly ash and micro silica with ratio of 80:20 respectively as the geopolymer cement. All cement samples are cured in two conditions, where the first curing condition is temperature of 80 °C and pressure of 1500 psia and the second curing condition is temperature of 120 °C and pressure of 3000 psia. Cement samples are cured for 7 hours and 24 hours in both curing conditions. Results obtained based on the test conducted gave out the value for the cements’ Poisson’s ratio ranging from 0.1886 to 0.2987; shear modulus vary from the lowest, 3.95 GPa to the highest, 5.49 GPa; and Young’s modulus ranging from 7.54 GPa to 14.39 GPa. The Geopolymer Cement has a higher elastic modulus compared to the Class G Cement for both curing condition.