HORIZONTAL WELL MAKING IN FORMATION WITH LOW THICKNESS Russian patent published in 2015 - IPC E21B7/06 

FIELD: oil and gas industry.

SUBSTANCE: average angle of bed slope to horizon is defined, against well-log curves for the neighbouring wells and drilling data at entry to the formation values of logging indicators are defined in the area of formation top, medium part and bottom, upon entry to producing formation direction of drilling is set against ascending path with angle of slope to horizon differing per 5-10% from the average angle of bed slope to horizon, horizontal borehole is drilled against ascending path with angle of slope to horizon within the specified limits and values of logging indicators are defined simultaneously. When values of logging indicators are reached in the area of formation top drilling direction is changed, drilling direction is set against descending path with angle of slope to horizon differing per 5-10% from the average angle of bed slope to horizon, horizontal borehole is drilled against descending path with angle of slope to horizon within the specified limits and values of logging indicators are defined simultaneously; when values of logging indicators are reached in the area of formation medium part drilling direction is changed to ascending path, at that drilling against ascending path and descending path is repeated till design reference mark is reached.

EFFECT: improved reliability and efficiency of well making in formation with low thickness.