Effects of Temperature, Pressure and Water-cement Ratio on the Setting Time and Strength of Cement

Petroleum engineers are displaying considerable interest in the problems ofcementing oil wells, especially in the Gulf Coast and California areas, wheresteep temperature gradients are encountered and where wells are being drilledto greater depths. Deep drilling, that is, at depths in excess of 7000 ft., hasbeen undertaken in these areas only in the last few years and with this trendoil-well cementing requires more technical treatment. It is not the purpose of this paper to describe the scope and application ofcement operations in the oil industry or to give the standard specifications, methods of sampling and testing of portland cement. The various testing methodshave been described by the American Society for Testing Materials!, Uren, Tickell and Wankowski and Rakestraw and Parsons The latter authors have alsodescribed in detail the methods of cementing. The authors realize that it is impossible to reproduce in the laboratory thescale of forces and dimensions that exist at great depths, but an attempt hasbeen made to scale down these dimensions proportionally. The selection ofproblems to be studied was based largely upon the practical questions asked byseveral of the largest operators in these fields. All cements used in theseexperiments met the specifications of the American Society for TestingMaterials.