The Effect of Neat Magnesium Oxide (MgO) as Expanding Additive with Burning Temperature 1200 C and 1300 C on Cement Shear Bond Strength at High Pressure and Temperature

Abstract

Good bonding between cement and casing and between cement and formation is essential for effective zone isolation. Poor bonding will create a problem in production operation both for geothermal wells and oil wells. Expanding additives, such as magnesium oxide (MgO) are used for improving primary cementing. Burning the dolomite (MgCO3) with high temperature in blast furnace produces the magnesium oxide (MgO) and it is milled with fineness 2800 ñ 3200 cm2/gram. The presence of mud film on casing wall and mud cake on formation will decrease shear bond strength, and for the composition without expanding additive it may reach zero. However, by adding expanding additives, shear bond strength of cement will increase, because the improved bonding is the result of mechanical resistance or tightening of the cement against the casing and formation. The objective of this research is to evaluate the effect of neat magnesium oxide as expanding additive with burning temperature 12000C and 13000C on shear bond strength at high pressure and temperature.