CEMENTING METHOD OF WELL Russian patent published in 2020 - IPC E21B33/13 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to gas and oil extraction industry and can be used in well construction. Method of cementing a well, comprising pumping into a column with a stop ring at the bottom of a buffer liquid, a grouting mortar, displacement fluid and subsequent displacement into casing annulus of buffer liquid and grouting mortar of different density, which is pumped in series. Injection is performed till maximum permissible pressure values for casing string and walls of the well walls are achieved. First, based on selected during drilling, determining maximum permissible pressure values for each formations and intervals of their location, based on which the allowable average density of grouting mortar and intervals of location is determined – opposite the weighted grouting mortar beds after pumping of the whole grouting mortar, between which a medium-density grouting mortar or light-weight grouting mortar is pumped to obtain an average density not exceeding the allowable average density of the grouting mortar.

EFFECT: proposed method of well cementing allows to expand the field of application due to possibility of reliable sealing without destruction of reservoirs, including high-permeable deep-seams formations opened by well, due to preliminary determination of intervals of beds location and maximum allowable pressure values for each of them with allowable average density of grouting mortar to exclude destruction of these formations.

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