一、何谓初级定向钻进? 当前,我国一些钻进容易发生倾斜的矿区,为了使钻孔钻达靶点,根据矿区促斜规律,依据地质设计的钻孔要素,在规定允许的偏线距离内,利用该矿区钻孔的自然弯曲规律,采取适当的钻进技术措施,促使钻孔按设计的轨迹延深。这就是通常说的初级定向钻进。 影响钻孔自然弯曲强度的因素较复杂,主要有地层的各向异性,产状变化,孔壁与钻具间的间隙,使用的钻具组合及其本身的刚度,开孔的顶角、方位角以及采取的钻探技术参数等。 二、如何设计初级定向钻孔? 初级定向钻孔设计方法基本上有两种,一是由上向下设计。另一种是由下（见矿点）向上设计,然后根据设计计算出钻孔位置、钻机安装角度等。具体设计方法有绘图法和计算法（解释法）,一般设计方法如下; 根据各矿脉已施工的钻孔偏离实际开孔方位线距离平均数值,扭角按下式求得; SillQ WWH tn.smo a = arc sll---- AH·5110式中:0——钻孔项角 a——安装钻机扭角 BD——实际钻孔落点偏线距离 设计所得角。为实际偏角。当安装钻机扭角时,若钻机实际按顺时针方向偏斜,向过时针方向扭a角,若逆时针方向偏斜时,应按顺时针方向扭口角。 H、如何保证初级定向钻进的实现? 初级定向钻孔施工,首先要做好矿区已完钻孔弯曲规律的统计工作,找出各种地层的自 First, what is the primary directional drilling? At present, some of our drilling prone to tilt mining area, in order to make drilling reach the target, according to the law to promote oblique mining, according to the geological design of the drilling elements, in the provisions of allowable offset distance , Take advantage of the natural curvature of the boreholes in the mining area and adopt proper drilling technical measures to promote the deepening of the borehole according to the designed trajectory. This is what is commonly referred to as primary directional drilling. The factors that affect the natural bending strength of the borehole are complex, including the anisotropy of the formation, the change of shape, the gap between the hole wall and the drilling tool, the combination of the drilling tool used and its own stiffness, the apex angle of the borehole, Angle and the drilling parameters taken. Second, how to design the primary directional drilling? There are basically two primary directional drilling design, one from the top down design. The other is from the next (see mine point) up the design, and then calculated according to the design of the drilling location, drilling rig installation angle. Specific design methods are drawing method and calculation method (interpretation method), the general design method is as follows; According to the mine veins have been constructed from the actual drilling hole deviation from the average azimuth line distance value, twist angle obtained by; SillQ WWH tn.smo a = arc sll ---- AH · 5110 Where: 0-- drilling angle a - installation of drilling twist angle BD - actual drilling offset distance from the design point of view. For the actual declination. When installing the drilling machine twist angle, if the drilling machine is actually skewed in the clockwise direction, turn the angle a to the outdated needle direction, and if the counterclockwise skew, the twist angle should be clockwise. H, how to ensure the realization of the primary directional drilling? Primary directional drilling construction, we must first do a good job of the mine has been drilling the bending of the statistical work to find a variety of strata since