Characteristics of Oilwell Cement Slurry Using CMC

Abstract

Summary The effects of carboxymethylcellulose (CMC) polymer with some other additives on Class G cement were investigated to design a slurry for a field in the south of Iran subject to tectonically induced horizontal in-situ stress. For a number of alternative slurries, characteristics such as compressive strength, permeability, free water, and fluid loss were examined. Fundamental theoretical studies and laboratory experiments were conducted using a system-based approach, endeavoring to minimize undesired properties progressively. The result was a cement slurry with specifications of early and high compressive strength, low permeability, suitable rheological properties, and a wide range of thickening time and suitable slurry for this case. Accordingly, the major contributions of this research lie in two aspects. First, a new package of additives is introduced to be used in similar cases in the oilwell-drilling industry. Second, a systematic experimental/theoretical approach for optimization of cement slurry in accordance with functional requirements is documented.