How to match the drill pipe of rotary drilling rig

Table of Contents

It is very troublesome to dismantle the drilling tools brought by the rotary drilling rig frequently up and down the bucket. The emergence of the telescopic active drilling rod has greatly improved the drilling efficiency and also reduced the labor intensity of the operator, how can we match the drilling rod of rotary drilling rig well?

drill pipe
drill pipe

1. According to the drilling capacity parameters of the drilling rig and the drilling diameter, the drillable depth, the diameter of the drill pipe is determining according to the empirical ratio of D/d=4.5.

The maximum allowable length of the rotary drilling rig drill pipe should be determining according to the effective height of the mast and the stability under self-weight conditions, and then the number of sections of the rotary drilling rigs drill pipe should be determined according to the design hole depth of the drilling rigs and the effective use length of each drill pipe.

2. According to the main parameters of drill pipe design, i.e. torque, feed pressure to rotary drilling rig drill pipe.

We know that the transmission torque of the drill pipe is transmitting by the engagement of the key and keyway extrusion torque, between them due to processing accuracy, material properties, welding quality, etc., it is impossible to ideally distribute the torque evenly on each key, each contact key is also impossible to uniformly contact the force, so long keys often appear to be locally twisting off damage, in the selection of rotary drilling rig drill pipe design torque must be greater than the design of the drilling rig Torque.

Rotary drilling rigs feed pressure is also the main external force on the drill pipe, the key design bearing capacity should be considering when selecting the drill pipe, especially the mechanical locking drill pipe, the main consideration should be the innermost minimum drill pipe diameter and wall thickness.

It is not only the smallest torque section modulus, and its bending section modulus is also small, rotary drilling rig drill pipe in the hole stress situation is very complex, tensile pressure torsional bending at the same time, and the synthetic drilling when stuck Stress may also exceing the fatigue limit of the drill pipe and be twisting off, from the outside we can not only consider the strength of the rotary drilling rig drill pipe, in fact, the working condition and nature of the drill pipe in the hole belongs to the instability conditions, so in the calibration of its bending strength should also consider instability.

3. Selection of drilling rod type of rotary drilling rig

The type of drilling rods is dividing into two types: friction type and mechanical locking type. The choice of drilling rods is mainly basing on the stratigraphic conditions, and general strata such as soil, sand, gravel and silt geological layers should choose friction type rods, while mechanical locking type rods should be chosen when encountering pebble gravel, drift stone layer, hard slate sand and hard rock layer. Rotary drilling rig drill pipe.

4. Quality of the drill pipe of rotary drilling rig

When choosing the drill pipe, you must also consider whether the maximum pull force of the main winch in the lifting system is compatible with the weight of the drill pipe of the rotary drilling rig, the weight of the drill bucket and the weight of the drill slag, because the weight of the drill pipe in the lifting weight accounts for about fifty to sixty percent of the lifting weight, and here we should especially mention the influence of the sudden braking during the lifting of the drill pipe of the rotary drilling rigs and the inertia force of the lifting from inside the borehole, the inertia force may account for thirty to forty percent of the lifting weight. The direction of this force is the same as the direction of lifting weight, so the choice of drill pipe weight of rotary drilling rig should be considering enough.

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