1. Pressurization Method

Regardless of the pressurization method, it is adjusted based on load and vibration.

1. Continuous Pressurization:

When drilling in soft and stable formations such as silt layers, due to light load, high-flow output and high rotation speed with continuous pressurization are used for drilling.

2. Intermittent Continuous Pressurization:

When drilling in clay or silty soil layers with 130 to 260 kPa, intermittent continuous pressurization maintains high rotation speed and low load drilling, avoiding unnecessary resistance increase from continuous pressurization.

3. Pressurization and Back-pressure:

When drilling in stable formations with high friction coefficients such as sand layers, the pressurization and back-pressure method can quickly reduce load and achieve fast drilling.

4. Point Pressurization:

When drilling in hard and vibrating geological formations such as round gravel or weathered rock layers above 500 kPa, which cause significant vibration, point pressurization is needed to force breakage and maintain a heavy-load drilling state. Back-pressure or continuous pressurization should not be used in such formations.

5. Continuous Pressurization Followed by Point Pressurization:

When drilling in hard and stable formations such as mudstone and sandstone, due to mud lubrication, continuous pressurization is needed initially; after cutting into the formation and load increases, point pressurization is used to maintain high-load drilling.

2. Drill Pipe Rotation Speed

Rotation speed output is controlled based on formation hardness and type.

1. Low Speed:

When drilling in highly vibrating gravel layers, it is necessary to avoid hard edges; low-speed drilling reduces vibration and effectively protects the rig.

When drilling in harder gravel and stable mudstone, low-speed drilling is more conducive to cutting into the formation; high-speed drilling may cause bouncing or slipping.

2. Medium Speed:

When drilling in mud-gravel, sand-gravel, or crushed stone formations, sudden load increases may cause blockage, breakage of edge teeth, or twisting of the drill pipe; medium-speed drilling protects rig components.

3. High Speed:

When drilling in stable formations such as mud and clay layers, high-speed drilling helps improve penetration rate.

3. Floating

1. Point Floating:

During hole opening, since the drilling bucket has no hole wall guidance, point floating can be used to control deviation; in highly vibrating formations, point floating can also be used.

2. Long Floating:

During normal drilling, long floating can be kept on to facilitate drilling.

3. Post Floating:

When drilling in weathered rock prone to deviation, point pressurization followed by floating can effectively prevent hole deviation.

4. Engine Speed

Based on differences in load and vibration, and when operating different actions, adjusting engine speed to control pump output power can match load with power, achieving emission reduction, noise reduction, energy savings, and effective protection of the rig.

Summary: During rotary drilling rig operation, controlling these four actions flexibly can meet various geological construction needs and protect the rig while improving drilling speed.