Investigation of Cement Compositions of Backfill Systems for Lining Wells with Inclined and Horizontal Sections

In order to increase the flow rate of oil wells in oil production and gas extraction industry, there is an increase in the construction of inclined-directed and horizontal wells. Despite the experience of drilling horizontal wells, their cementing still does not have the required quality. For these areas, incomplete replacement of drilling mud with cement slurry is noted due to irregularities in the walls of the well, insufficient centering of the casing in the wells, sedimentation of process fluids. As a result, there may be no contact of the cement stone with the casing and rock in this zone, which leads to a violation of the tightness of the cement stone and the appearance of cross fluid flows. Thereby, the development of new compositions of cement slurries and well completion methods is a crucial task in the field of construction of horizontal wells for hydrocarbons. The research work presents the results of a study of the effect of various additives - hollow aluminosilicate microspheres, hydroxyethyl cellulose, magnesium oxide, polymer material "Cleon-SP36", superplasticizer C-3, basalt fiber on the structural, rheological and strength properties of cement slurry and cement stone. Sedimentation-stable compositions with improved strength characteristics of a cement ring for lining horizontal sections of wells, allowing to increase the efficiency of oil field development are proposed. The developed backfill compound based on PCB I‑50 is designed for cementing oil and gas well casings at low and normal temperatures (15-50 °C), as well as taking into account the physico-mechanical characteristics of the hollow aluminosilicate microspheres (HAMS) – the recommended application depth is up to 3000 m vertically.