A combined study of the performance and hydration of a Class G oil-well cement derived from Greek raw materials

Abstract Common construction materials cannot guarantee the integrity of an oil-well where high pressure & high temperature conditions exist. Proper well-cementing ensures its productive life with the used cement-slurry consisting mainly of proper cement ( conforming to the American Petroleum Institute specifications ). A potential market for oil well cements is expected to grow in the next decade as a consequence of the recent oil and gas findings in the NW and SE Greek Mediterranean region, triggering attraction of financial investment in the energy sector and a necessity for developing production of oil well cements deriving from Greek raw materials. In this research, the key parameters for the development (design & production) as well as characterization of an API Class G oil-well cement are investigated. Initially, the suitable raw materials were selected; the as-produced raw meal was burned properly and the produced clinker was studied in terms of mineralogy, microstructure and morphology. Afterwards, clinker was crushed & ground with natural gypsum (CaSO 4 ·2H 2 O) and the final cement's physicochemical properties were determined. Cement hydration study was performed as to identify the main hydration products ( after 2, 7, 28 and 90 days of curing in atmospheric conditions ) and the laboratory produced oil-well cement was characterized according to API 10A standard. Lastly, the laboratory produced oil-well cement was compared to a commercially available one.