Guided drilling technology definition: a highly efficient bit and power drilling tools and MWD of an organic whole, computer software, and the auxiliary of steering drilling system. It is used in oil drilling engineering, can change orientation timely. Working condition of two kinds of rotary table, continuous directional deflection, oblique, stabilization, fall and torsion bearing operation, without the drill assembly, change can quickly drill out high quality drilling method of wellbore trajectory.
The drilling phase:
1. According to the guidance tool points: It can be divided into the slide steering drilling and rotary steering drilling two stages.
Slide steering drilling operations, drilling string does not turn, the drill string with bit sliding forward propulsion.
(1) The drill string torque and friction problem;
(2) The hole cleaning problems;
(3) Mechanical drilling rate is slow;
(4) Bit selection is limited.
Rotary steering operation, the drill string with drill bit rotation. Hole cleaning is good, but resistance moment, drilling torque can lead to the lower part of the torsional vibration of the drill string, and large investment.
2. According to the guide way points, can be divided into geometric steering drilling and geosteering drilling two stages.
Thedownhole MWD tool to measure the geometric parameters: the hole deviation and azimuth and tool numerical control system to below, by the control system in a timely manner to correct and control the well track.
With geometric orientation ability at the same time, can also according to logging while drilling (LWD) geological parameters have been measured, the real-time control of borehole trajectory, bit along the formation of the optimal position to move forward.