1, some regularity of drilling bending

(1) in a horizontal hole or tilted hole drilling, drilling azimuth Angle change is not big, mainly borehole tilt Angle change.

(2) drilling shallow, depending on the level of hole drilling rock buried given by different (rock dip Angle, Angle of drilling in the layer, rock anisotropy, etc.), as the drilling floated on deepening its Angle is mostly into the trend.

(3) in the schist and gneiss layer in obvious drilling shallow metamorphic rock of the earth drilling, drilling inclination of the sagging trend.

(4) when drilling deep hole bend law is divided into two sections, beginning period of drift Angle, then gradually went straight hole section to the inclination of prolapse.

(5) the reason of drilling bending is also geological factor and technology factor combination.

2, drilling, bending of prevention

To prevent drilling bending, according to the laws of the region borehole bending in the opposite direction in advance a pre-twist Angle or on drilling tools with adopting the necessary protection measures to deal with.

3, the construction of drilling bit can use the surface of large dip Angle of conventional inclinometer, and in a horizontal hole, must adopt special measuring instrument.

Such as domestic XJS - 35 type special lateral horizontal inclinometer (for non magnetic ore body), main technical parameters are as follows:

Length measuring instrument outside diameter x: 30 mmx1100mm 30;

Drift diameter: 0 ° to 60 ° (Yang, prone), dividing value 2 °, error of plus or minus 1 °;

Azimuth measurement range: 0 ° to 360 °, dividing value 2 °, the error of plus or minus 2 °