Drilling and coring means to master the underground geological conditions. The operation of obtaining real and reliable data of underground rock strata directly and using coring tools to extract large rock samples (cores) from underground during drilling.

At present, diamond coring bits are widely used in drilling and coring at home and abroad.

1) portable diamond core drill has a good operating effect and can ensure the uniform edge of the drill. Diamond wear-resisting, matrix erosion resistance, so smooth drilling, fast speed, high harvest rate, long service life, good comprehensive economic benefits.

2) portable diamond core drill has a wide application range. From the extremely soft and extremely hard strata, there are various series of diamond coring bits to choose from, which can fully meet the requirements of coring under various conditions.

3) the matrix diamond coring bit is easy to form, easy to process and has a high yield.

Coring procedures

1. Core tool assembly
1) lay the coring tool flat on the ground, tighten the connecting thread of each joint with chain tongs, and wrap the protector wire at both ends.

2) check whether the outer diameter of the stabilizer is consistent with the drill bit, and measure the length of the core barrel.

3) after hoisting on the drilling floor, use the hoisting card to go down into the well, use the slip card under the upper stabilizer, and use the safety slip card.

4) remove the safety joint, put forward the inner barrel, connect the inner barrel shoes with core claw to the inner barrel, and tighten them with chain tongs.

5) lower into the inner cylinder, check whether the safety joint and bearing are flexible, apply thread oil (not too much), tighten the buckle with chain tongs, and finally tighten with tongs.

2. Drill down The downhole section with reduced diameter should be entered slowly. If there is any resistance, the pump should be opened for circulation first, and the short section with low bit pressure, low rotation speed and large displacement should be operated smoothly. The operation should be stable and should not be released, stopped, brake or rotated violently to prevent the drill string from swinging violently. In the well, slant big, short time ream. It is prohibited to use a coring bit for large (10 meters or more) drilling or forced drilling.

3. cycle Circulate drilling fluid when drilling from 0.5~1 m to the bottom of the well, move smoothly and rotate the drilling tool properly. Calibrate the weight indicator to find out the actual bottom of the drill pipe, unload the lifting drill pipe and put the steel ball into it. After the pump pressure rises, do the pressure drop test of the drill bit.

4. Make the core Start the rotary table first, slowly apply drilling pressure, test run with low rotation speed and light drilling pressure, wait for smooth operation, drilling 0.3~0.5 meters, gradually adjust to the normal coring drilling parameters.

5. drilling The drilling pressure during core drilling should be determined according to the hardness and drill ability of the rock, the type of drill bit and the structure and strength of the drill tool. Drilling pressure must be greater than the formation compressive strength, otherwise, no footage. If the drilling pressure is too small, the drill bit teeth into the formation less, although there is footage, drilling speed is very slow, the drill bit wear quickly; The greater the drilling pressure, the deeper the drill bit penetrates into the formation. Drill faster.