To increase the efficiency of drilling horizontal wells, the formation of a rotary-regressive flow of flushing fluid is justified. In this flow it is possible to increase in hundreds times active forces causing cuttings removal. The use of the swirling flow when drilling a horizontal borehole allows to reduce the construction time and cost of the well.
A study of formation fluid inflow into the well has been carried out and the strong influence of formation anisotropy has been revealed. The method of calculation of horizontal well drilling along arc and linear profiles, tested at Yaraktinskoye field of Irkutsk region, is described.
