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General drilling to directional drilling-beneficial mining technology
Release time:
2021-09-29
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The first type of guide drilling tools commonly used in general drilling to directional drilling and horizontal directional drilling is the dental plate drill bit. There are many names for this kind of drill bit. Foot drill bit, duck palm drill bit and guide plate drill bit all refer to this kind of drill bit. There are different designs for different strata. The plate has both a common type with one bend and an enhanced type with two bends. Generally used for soft to medium hardness and more uniform hardness of clay, or loose to more dense sand. Steering method: when drilling straight holes, the drill pipe is rotated and pushed; when steering adjustment is needed, stop the rotation of the drill pipe, and after the working situation is adjusted to the direction that needs to be adjusted, only push the drill pipe without rotating it.
Several kinds of guide drilling tools commonly used in general drilling to directional drilling and horizontal directional drilling
The first: dental plate drill. There are many names for this kind of drill bit. Foot drill bit, duck palm drill bit and guide plate drill bit all refer to this kind of drill bit. There are different designs for different strata. The plate has both a common type with one bend and an enhanced type with two bends. Generally used for soft to medium hardness and more uniform hardness of clay, or loose to more dense sand. Steering method: Rotate and advance the drill pipe when drilling straight holes; when steering adjustment is required, stop the rotation of the drill pipe, and after the work situation is corrected to the direction that needs to be adjusted, only push the drill pipe without rotating it. Pay attention to the steering angle during the advancement. Change to prevent oversteer.
The second: rocking top bit. Tilting bits are suitable for hard formations and soft rock formations that cannot be penetrated by propulsion alone. Steering method: when making a slope towards the required steering direction, make the drill bit rock back and forth clockwise/counterclockwise (commonly known as topping), and rotate the drill pipe like the dental plate drill bit when drilling in a straight line.
The third type: whipping short-circuit hole bottom drilling tool assembly (BHA). This kind of drilling tool assembly is generally used for large directional drilling soft formation crossing. The oblique short is generally 30 to 2 degrees, usually combined with milling three-cone bit, in case of hard formation, the thrust is large; in case of soft formation, the oblique effect is not obvious. The guiding method is the same as the dental plate drill.
The fourth type: Mud Motor BHA (Mud Motor BHA). Mud motor is not only a whipbuilding tool, but also a drilling power tool. Generally, it is only used with three-cone bit. It is mainly suitable for hard formation, and only mud motor can be used in rock formation. For through the lower soft strata, due to the weight of the screw and sink, resulting in difficult to raise.
Directional control in the mud motor is achieved by a bend of up to 3 degrees (typically 1.75 degrees). The elbow is located approximately 1.5 meters behind the drill bit, and its function is the same as that of the elbow. The shorter the distance from the drill bit to the bend, the greater the bend angle, and the faster the steering. The steering method is the same as the steering method of the dental plate drill bit.
The fifth type: double-wall drill pipe rock drill guide system. This drilling rig has two sets of top drive devices, specifically driving the double wall drill pipe system. The bottom hole assembly is very similar to a mud motor, but without the drive portion of the mud motor. Steering method: The drill bit usually uses a three-cone drill bit. The drill bit is driven by the inner drill pipe to rotate continuously, while the outer drill pipe is used to control the steering, that is, to adjust the bending cover to the correct direction.
In the middle of the period, the bend cover is also used as a support for the rotary drill bit and accommodates the probe rod; the inner and outer drill pipes rotate and drill in a straight line at the same time. The probe is placed close to the tail of the drill bit, which increases the speed of the steering response compared to most mud motors, because the structure of the drill pipe cannot use a wired guidance system.
For short distances, the formation belongs to soft to medium hard rock, and the limited area of the workplace does not allow the use of large drilling rigs and mud pumps to drive the mud motor crossing, this system is very suitable and efficient. But for large-diameter, long-distance hard rock crossings, the efficiency of this system is lower than that of mud motor equipment.
The sixth type: horizontal directional drilling down-the-hole hammer drilling tool assembly. This kind of drilling tool is powered by compressed air, which is suitable for small drilling rig to cross short distance, medium to high hardness rock formation, and its efficiency is higher than other guiding tools.
This system steering is achieved by an eccentric, flat face drill with tungsten carbide teeth. This drill bit has a high point and can be better oriented in the direction of the desired path during the non-rotating only advance. If straight drilling is required, it is only necessary to apply a moderate drilling force while rotating slowly.
Key words:
Technology, drill bit, steering, formation, motor, this, mud, rotary, drill pipe, method
