OREANDA-NEWS. August 03, 2009. OAO TATNEFT has built 200 new horizontal wells and about 50 lateral horizontal wellbores in the oilfields of Tatarstan. Drilling of such wells is performed in the oil fields with complicated geological structure, reported the press-centre of TATNEFT.

The drillers have mastered the technology of drilling branched horizontal wellbores both in different productive strata, as well as same layer. Drilling in productive layers is carried out in the mode ensuring maximal preservation of the natural reservoir permeability. Average oil production rates of the horizontal wells and the lateral horizontal wellbores is significantly, sometimes two-fold, higher, than the production rates of vertical and directional wells.

Drilling of the horizontal wells is performed with application of screw type downhole motors with variable geometry and MWD telemetry systems with hydraulic and electromagnetic communication channels. The length of the conventionally horizontal wellbore section in the formation extends up to 650 meters. Penetration is carried out through the mostly oil saturated part of the formation within a one meter "corridor" of drilling thickness.