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What are the "Ten Principles" for determining when a diamond drill bit can no longer be used? The "Ten Principles" are:

Inner and outer diameters wear beyond the allowable tolerance;

Abnormal wear has occurred;

The diamond-tipped drill bit has already fallen off;

The diamond-embedded drill bit exhibits slight burning.

The tire body has cracks;

The drill bit shows uneven wear and deformation;

The drill bit's outer diameter is equal to or greater than the reamer's outer diameter;

Wear on water inlets and sinks;

The diamond-tipped drill bits exhibit cracking and shearing phenomena.

The diamond segments are exposed more than 1/3 of their height, or the matrix has suffered severe erosion due to excessive pumping volume.

Diamond drill bits exhibiting the above-mentioned issues, whether untreated or still failing to meet usage requirements even after treatment, must not be lowered into the borehole.

What are the key considerations for wisely selecting and using diamond drill bits?

Drill bit selection depends on the formation: categorized by abrasiveness as weak, medium, or strong; classified by integrity as fractured or relatively intact; and graded by drillability as soft, medium, or hard. When these three factors are properly matched, the results are significantly improved. Drill bit specifications must be carefully inspected, with bits sorted by size and rotated for consistent use across shifts. Drill bit management should be assigned to each work team, ensuring rational utilization and thorough documentation on the corresponding cards.

What are the key considerations for rationally selecting diamond drilling parameters?

Drill into the formation while optimizing parameters: prioritize speed but maintain appropriate weight on bit. Ensure sufficient fluid volume—this allows for higher pump pressure. Adapt drilling practices to the specific formation characteristics; avoid rigidly applying standard procedures. When starting the drill, apply light pressure and rotate slowly. Once drilling stabilizes, return to normal operating conditions without further adjustments. If you encounter challenging conditions—such as highly fractured or abrasive formations, oversized boreholes, or excessive wellbore curvature—reduce the rotational speed immediately. Finally, keep the mud flow path clear to prevent bit overheating. Maintain proper pump rates to ensure the drill bit remains in optimal condition.

What are the key considerations for selecting diamond drilling tools?

Various types of tubing are carefully selected; drill tools must be straight, free from bends or twists. Avoid using tools that are skewed or flattened—discard any with visible depressions. Double-tube drill tools undergo individual inspection to ensure quality. Pay close attention to the degree of wear when choosing and examining them. Make sure the retaining clips are properly matched—this prevents clogging or detachment. When hammering the core sample, always handle the inner tube with care: using an iron hammer can easily cause dents, while a wooden mallet is gentle enough to avoid damage altogether. When removing the drill bit, never use pipe wrenches—these tools have too few contact points, making them prone to crushing the bit. Instead, opt for ring-type pliers, which are the best choice for maintaining the bit’s round shape. *Note: "Not堵脱残" means the core sample remains unobstructed, securely attached, and free of residual material.*

What are the key techniques for preventing bit burning during diamond drilling?

Leaking threaded connections may seem minor, but don’t underestimate their importance—ensure proper sealing to prevent bit burnout. Follow the drawings precisely during machining, and conduct rigorous inspections afterward. Avoid twisting or loosening the end fittings; instead, use resin bonding for secure attachment. Apply oil to the threads, making it easy to repeatedly tighten and loosen the casing. For added reliability, wrap cotton thread around the threads and insert a washer if needed. Securely mount the pump, and ensure the belt is properly tensioned to prevent slippage. Replace the three-way joint promptly if it shows signs of wear or failure. Use a variable-speed pump for optimal performance. Stay fully focused and closely monitor all instruments. If the core becomes stuck, immediately pull the drill string. And if you notice an unexpected increase in drilling speed, slow down—don’t rush! Carefully assess the hole conditions to avoid damaging the drill bit or causing overheating.

What are the precautions to take when using diamond drilling?

Pump pressure and drilling weight—observe the ammeter readings carefully while operating; keep all three gauges in view at once. If the pointer remains steady, the wellbore is safe. But if it suddenly rises or drops sharply, it signals an abnormal condition. When you spot a problem, don’t panic—immediately lift and pull the drill string, then shut down the rig. If core bits become stuck or the drill string fails to move freely, promptly raise the drill string without delaying the operation. Regularly flush the borehole to bring cuttings to the surface, ensuring the wellbore stays clean and preventing overheating of the drill bit. For deep-hole operations involving rod handling, always stop the rig first. Secure the drill rods tightly before releasing the chuck. *Note: "Three gauges in view" refers to the pump pressure gauge, drilling weight gauge, and system pressure gauge.*