The Impact of Additively Coal Fly Ash toward Compressive Strength and Shear Bond Strength in Drilling Cement G Class

: The successful of cementing process in petroleum is indicated by the strength value consisting of the compressive stress value and the shear bond strength value. The value of compressive strength permitted in drilling is 500 psi while for shear bond strength is 100 psi. To increase the strength of cement is done by adding pozzolanic additives. One alternative pozzolan that can be used and derived from inorganic waste is coal fly ash. Indonesia has reserves of around 38.9 billion tons of coal with annual production reaching 435 million tons, resulting in a large amount of coal fly ash. The silica contained in coal fly ash is pozzolan which can increase the strength of cement and can reduce costs because it does not need to use additives from industry and can also reduce environmental pollution from fly ash. This study was conducted to determine the value of compressive strength and shear bond strength by using coal fly ash additives with variations in concentrations of 2.5%, 5%, 7.5%, 10%, 12.5% and 15% by weight of cement (BWOC). Making cement suspension samples is done by mixing water, bentonite, polypropylene glycol, CaCl2, and coal fly ash softens the mixer, then it is poured in a mold and left in the water bath. The residence is carried out for 24 hours with temperature 60 0 C. Compressive strength and shear bond strength test can be done by utilizing hydraulic pressure. The addition of coal ash can increase the strength of cement. The optimal compressive strength and shear bond strength is obtained on 7.5% BWOC additively ash coal with the value of compressive strength obtained is 1680.39 psi and the shear bond strength is 138.88 psi.