Published March 2012

Isolation of the second bore while drilling inclined wells

D.S. Akhundov

G.V. Djabbarova

Complication in drilling is a technological situation which breaks a normal course of well drilling process. The prevention of complications liquidation in the stage of inclined wells drilling demands a special approach. Often while studying the complicated inclined bores the wells inclination parameters and the calculated sizes of BHA are not taken into consideration which leads to predrilling of second bore of the well. As a result of this additional serious complications appear. Due to lesser intensity the inclination is always directed to the second bore while drill string running. In order to isolate the second bore from the basic one in the BHA content the kick sub with 2о angle of curvature is applied. BHA is run to the kick off point. By means of drill string run into the well the main bore direction is designated and notes are made on drill pipes and rotary tables. After the direction is changed the drill string is run into the second bore and its cementing is performed. After the cementing the drill string is lifted to the previously marked kick off point and accordingly to made note is run into the main bore. By means of intensive washdown the cement slurry excesses are erased from the well to the surface. While cement slurry excesses washdown to the full output to the surface the drill string is constantly reciprocated for a length of 1516 m.