| 摘要 |
<p>A system and method for controlled directional drilling utilizes a system approach to design the hardware for drilling according to the well plan. The bend angle of a bent housing, connected between the bit and a down-hole motor, the diameter of a plurality of stabilizers and placement of the stabilizers with respect to the drill bit are selected and predetermined on the basis of the desired well plan. With the use of an MWD, the direction of the progressing borehole is tracked from the surface. Direction changes as required are controlled from the surface simply by controlling rotation of the drillstring. For curved path drilling, only the downhole motor is rotated, causing the borehole to travel along the curve determined by the bend angle in the bent housing and the diameter and location of the concentric stabilizers. When straight hole drilling is required, both the down-hole motor and the entire drill string are rotated, effectively nullifying the effect of the bend angle in the bent housing.</p> |
