Small Rotary Drilling Rig, Bailey Sheet Supply, Small Rotary Drilling Rig Construction

Product Details

Main Structure of Small Rotary Drilling Rig

1. The chassis structure adopts a specialized design with a retractable crawler chassis. The four wheels and one track have the characteristics of reliable structure, good rigidity, large bearing capacity, and good stability, which strengthens the structural rigidity and working stability of the whole machine.

2. Turntable. The turntable mainly consists of a slewing reducer, slewing bearing, turntable body, mast support, etc. Its function is to carry the upper weight and enable slewing motion. The turntable of this machine is adapted to the specialized chassis structure, can be installed with main and auxiliary winches internally, and ensures sufficient installation space for the main and auxiliary winches. This not only ensures the reasonable layout of the overall structure and center of gravity, good working stability, but also enables the main and auxiliary winch drums to adopt a large-diameter structure to reduce the number of winding layers of the wire rope on the drum, thereby reducing the mutual extrusion and friction of the wire rope from the structural design and improving the service life of the wire rope.

3. Main and auxiliary winches. The main winch adopts a large-diameter drum structure, which effectively solves the mutual extrusion and wear between the wire ropes in the multi-layer winding structure and ensures the service life of the wire rope. The main winch can achieve dual-speed control and has a free-fall function to meet the needs of drilling. The control mode is hydraulic pilot control, and the main and auxiliary winches are equipped with rope presses.

4. Power head. The power head mainly includes a bracket and a driver. The hydraulic pump supplies oil to drive the hydraulic motor, which then passes through the reducer and drive gear to transmit low-speed and high-torque power to the drill pipe through the casing-type drive shaft.

5. Drill pipe. Generally, domestic reliable quality supporting parts are selected.

How to deal with problems during construction of rotary drilling rig and casing faults

Under no circumstances shall construction personnel be allowed to enter a borehole without a casing or other protective facilities to handle faults. When it is necessary to enter a borehole with a casing or other protective facilities, it should be checked that there is no harmful gas in the hole, and safety facilities such as anti-poison, anti-drowning, and anti-collapse burial are fully prepared before action.

Collapse hole

During the pouring process, if it is found that the mud level in the casing suddenly rises and overflows the casing, then suddenly drops and bubbles appear, it should be suspected as a sign of hole collapse, which can be detected with a sounding hammer. If the sounding hammer was originally suspended on the concrete surface and not taken out, and is now buried and cannot be lifted, or when the sounding hammer detects the concrete surface but cannot reach the original depth, with a large difference, it can be confirmed as hole collapse.

Borehole deviation

When encountering borehole deviation or bending, the cause should be analyzed and handled. Generally, the drill cone can be suspended at the deviation point and repeatedly swept to make the borehole straight; in severe cases, cohesive soil should be backfilled to the deviation point, and drilling should be resumed after sedimentation and compaction.

Hole enlargement and shrinkage

When encountering hole enlargement or shrinkage, measures should be taken to prevent hole collapse and excessive swing of the drill cone. Hole shrinkage is caused by excessive wear of the drill cone, untimely welding repair, or soft soil and clay mudstone that expand with water in the formation. For the former, attention should be paid to timely welding repair of the drill cone; for the latter, high-quality mud with low water loss rate should be used for wall protection. When hole shrinkage has occurred, the drill cone should be repeatedly swept up and down at that location to enlarge the hole diameter.

Drill bit clogging and burial

Drill bit clogging and burial often occur in positive circulation (including submersible drilling rigs) internal rotary drilling and percussion drilling. In such cases, the mud consistency, drill slag inlet and outlet, drill pipe inner diameter size, and slag discharge equipment should be checked and calculated, and appropriate footage should be controlled; if severe clogging has occurred, drilling should be stopped, the drill cone should be lifted, and drill slag should be removed.

Drill dropping and falling objects

When the drill drops or objects fall, tools such as fishing forks, hooks, and rope slings should be used quickly for fishing. If the fallen object has been buried by mud and sand, according to the above items, first remove the mud and sand, so that the fishing tool contacts the fallen object before fishing.

During the construction of rotary drilling rigs, sometimes the casing sinks, causing work stoppage and cost consumption. What are the reasons?

1. The backfill soil is not compacted when burying the casing.

2. The water level difference in the casing is too large.

3. The drill bit collides with the casing when lifting and lowering.

There are three methods to prevent sinking:

1. When burying the casing, the pit bottom and surroundings should be compacted layer by layer with clay of optimal moisture content.

2. Open holes at appropriate heights on the casing to maintain a water head height of 1~1.5 meters inside the casing.

3. When lifting and lowering the drill bit of the rotary drilling rig, the operator should concentrate and slow down to avoid the drill bit colliding with the casing.

Treatment methods for casing sinking:

1. When water is found bubbling around the casing at the beginning of drilling, clay can be used to fill and reinforce around it.

2. If the casing is found to sink or displace during drilling, the casing should be fixed to the drilling rig with a wire rope or tied to a large length