1, some regularity of borehole bending
(1) in the horizontal hole or inclined hole drilling, the borehole azimuth angle change is not big, mainly is the borehole inclination change.
(2) When the borehole is shallow, the buried condition of the rock is different according to the horizontal hole (rock inclination, the borehole layer angle, the anisotropy of the rock, etc.), which is the trend of the upward drift as the borehole deepens.
(3) in schist, gneiss and other layers in the obvious metamorphic rock in the shallow drilling hole, the borehole inclination is drooping trend.
(4) The borehole bending regularity is divided into two sections, and the initial inclination is drifted, and then the inclined hole is gradually drooping.
(5) The causes of borehole bending are also caused by the combination of geological factors and technological factors.
2, the prevention of borehole bending
In order to prevent the bending of the borehole, it can be solved by the rule of the borehole bending in the area in advance in reverse direction or in the drilling fixture.
3, the construction of large dip hole can use the surface bit of the conventional inclinometer, and in the horizontal hole, the special measurement equipment must be used.