Drilling Bit Hole Opener
How to improve drilling efficiency, especially for big diameter hole, is the hot topic for all borehole drillers. By reaming, it is a good way to Get big diameter borehole.Roller type hole opener is the best one among all the hole openers. It can improve the drilling efficiency by 20% compared to other type of hole openers
Cone type reamer/Hole Opener
As shown in below picture, part 1 pilot rock breaker is a tricone bit and
There are many pieces of rotary bit for opener for part 2
Function of stabilizer
Stabilizer is installed between drill bit and drill rod, the function
Is to keep the hole straight and get a smooth hole surface
With stabilizer, the drill bit will only rotated in his own centerline, which can make
Borehole drilling stable and less vibration and less energy loss.
When making deep borehole drilling, the stabilizer can be put in the middle of drill
Line, which can avoid contacting between drill rod and inner surface of hole due
To deformation of drill pipe. In his way, it also can have drill pipe rotating
Around their own centerline and cause less vibration and bear less rotary torque.
Type of Stabilizer
There are 2 type of stabilizers are very common used now
One is rod type and the other is stick type
Rod type is weld anti wearing layer on the surface of stabilizer to have drill pipe
Rotating on their own centerline.
Stick type is weld a couple of stick on the surface of stabilizer, but the stick will be
Wear out very fast in condition of hardrock due to stick always scraping with inner
Surface of hole.
Tricone Bit or Rotary Drill Bit Introduction
Drilling tools of Rotary drilling rig including drill rod and Tricone bit
They are key tools for borehole drilling
Sometimes in order to have big diameter hole and avoid the impact back
From borehole drilling, and get vertical hole shape. The reaming tools,
Damper and stabilizer etc, assistant tools. All of them belong to drilling tools
Upper end of drill rod connect with adapter in top head, while lower end connecting with
Tricont bit. The drilling fluid( air or mud) coming into borehole via top head,
Inner Drill rod and blow cutting out of the hole.
During drilling, rotary rig drive the drill bit rotation by top head, and
Top head can move up and down to get feeding force to drill bit to break rock
Tricone Bit Configuration
Like in picture, tricone bit has 3 main components. Bearing, roller and
Palm of roller
Roller installed on axle of palm, and bearing is between roller and palm, roller
Can rotate via bearing during drilling. It can break the rock by the teeth embed
In the palm.
When drilling, feeding cylinder make the drill bit compress on the rock tightly
And top head drive drill bit rotating. In this way, it can break the rock.
Due to rotary movement from tricone bit, the teeth on the palm will impact rock
Continuously to get rock broken. And for soft rock, shearing force is key
Therefore, tricone bit is breaking rock by shearing force and impact power together
Type of Tricone Bit
According to number of palm, single palm tricone bit, double palm tricone bit and triple tricone bit
Single palm rotary bit is not used so often, due to its short lifetime
Double palm rotary bit is not used often as well, even though it has faster drilling speed. But its short lifetime affect
It is not so popular by market
Triple and four palm rotary bit is very popular due to it can bearing the force by 3 or 4 balanced palm and it has
In terms of shape of teeth
There are steel type of tricone bit and insert type of tricone bit,
Steel type of tricone bit is normally drilling for softrock condition
Insert type of tricone bit is for hardrock and medium hardness rock, It has IADC 417, 437, 517, 537, 617, 637etc.
Drill Rod/Drill Pipe
Rod is welded by seamless tube and threaded adapter at two end.
The function of rod is transmit the rotary movement and feeding force
From top drive and feeding cylinder to drill bit.
It also will have drilling fluid to go through the pipe to bottom of hole to
Blow the cuttings out of the hole
Below is picture is showing the configuration of rod.
There are slots in the rod for wrench when changing drill pipes. There are
Different length and diameter drill pipe according to different size of drilling machine