METHOD FOR DRILLING A LARGE DIAMETER VERTICAL WELL

摘要

Disclosed is a method for drilling a large diameter vertical well. At preparation of drill string to drilling, at its lower end one additionally installs central bit axis of which is coaxial to the longitudinal axis of the string, and the bit of the bottom motor is fixed on spindle shaft in such way that its axis is directed at angle to the axis of the spindle shaft of bottom motor. Well drilling is carried out with destruction of the central section of the well bottom with rotation of the central bit round the long axis of the string, with formation of the well to end diameter through reaming central section of the well bottom with additional rotation of the bit of bottomhole motor with respect to axis arranged at angle to the axis of the spindle shaft of bottomhole motorin such a way that bit can describe a conical surface with respect to the axis of the spindle shaft.