How to Use a Diamond Drill Bit

I. Pre-Drilling Preparation for Diamond Drill Bits
　　1. Inspect the previous diamond drill bit for damage to the bit body, tooth loss, or other defects, and confirm that the bottom hole is clean and free of debris.
　　2. Handle diamond drill bits with care; place them on rubber mats or wooden boards. Do not set diamond drill bits directly on steel plates.
　　3. Inspect the diamond drill bit for damage to the cutting teeth, check for foreign objects inside the bit, and verify that an O-ring is present in the nozzle bore; install the nozzle as required.
II. Make-up of Diamond Drill Bits
　　1. Clean the male or female connection of the diamond drill bit and apply thread lubricant.
　　2. Clamp the swivel wrench onto the diamond drill bit, then lower the drill string until it makes contact with the male or female connection and tighten the joint.
　　3. Place the diamond drill bit and the slip‑on tool together into the rotary table bushing, then tighten the threads to the recommended make‑up torque.
III. Drill Down
　　1. Lower the diamond drill bit slowly, paying particular attention to the rotary table, blowout preventer, and casing hanger, to protect the cutting teeth. 2. Be mindful of the well sections that encountered resistance during the previous trip out; during the trip down, if you encounter under‑reaming or doglegs, guide the drill bit through these areas at a slow rate.
　　3. When approximately one single pipe length remains to the bottom of the well, begin rotating at a drilling speed of 50–60 rpm and pump at the rated flow rate to flush the bottom of the well.
　　4. Carefully monitor the load indicator and torque to ensure the diamond drill bit makes smooth, even contact with the bottom of the well.
IV. Diamond Drill Bit Spotting
　　1. It is not recommended to use diamond drill bits for reaming well sections.
　　2. If reaming is required, perform the operation at the rated flow rate, using a slow speed and low torque.
V. Diamond Drill Bit Design
　　1. Maintain the rated displacement and lower the diamond drill bit to the bottom of the well.
　　2. Perform slow drilling for at least 1 meter to establish a bottomhole model.
　　3. Increase the drilling weight in increments of 10 kN until it reaches the normal drilling value; avoid applying excessive pressure, which could lead to premature failure of the diamond drill bit.
　　4. Maintain constant weight on bit and adjust the rotary speed to achieve a standard drilling parameter combination.
VI. Normal Drilling with Diamond Drill Bits
　　1. When encountering highly abrasive or hard sandstone‑shale formations, reduce the drilling rate to extend the life of the diamond drill bit.
　　2. When encountering changes in formation or interbeds, adjust the drilling rate and the diamond drill bit to maintain standard drilling performance.
　　3. When connecting each drill pipe, observe the following points: 3.1 Restore the pump strokes and check the standpipe pressure. 3.2 In…
　　Before the diamond drill bit contacts the bottom of the well, start pumping and slowly lower the bit to the bottom at a rotational speed of 50–60 rpm. 3.3 Gradually resume applying weight on the bit to the original level, then increase the rotary speed back to its original value.
　　Certificate of On-site Use,
　　When drilling in soft to medium-hard formations, diamond drill bits offer numerous advantages, including high penetration rates, substantial footage per bit, extended service life, smooth operation, reduced downhole incidents, and superior wellbore quality. Moreover, diamond drill bits not only have a long service life but can also be reused; refurbished bits delivered to the factory perform comparably to new‑from‑the‑factory units, resulting in significant savings on drilling costs.