Operation points of three - cone bit

　　Operation points of three - cone bit

　　1. Before entering the well: (1) a fishing cup is installed on a drill bit. After the first drill bit is out, the cone bit is in front of the well. Check the wear condition of the outside diameter and other wear conditions. If the outside diameter is normal, the diamond drill can enter the well. Check for any damage to the cutting teeth; Check for blockage of water eye; Check the outer diameter of the drill bit; Whether the drilling fluid meets the design requirements; Whether the cleaning equipment is working properly. It is recommended to use the desander.

　　2. The bit low pressure contact hole bottom, use the underground power drilling tool to drill a bit near the bottom of the shaft to open pump and gradually increase to the requirement displacement; After cleaning the well bottom for a short time. Then slowly increase the weight of the drill. 3. When the drilling pressure increases, the pump pressure also increases correspondingly. The change of pressure and the numerical value of the drilling pressure must be controlled in the technical specification of the recommended motor. 4 the drill pipe should be rotated slowly to prevent sticking. All other standard operation according to ordinary rotary table. 4. Special precautions: 1 bit is not suitable for drilling gravel layer; Drilling into the gravel layer, drilling ahead, drilling into the cone bit, through the gravel layer, and then into the diamond bit; 2. Prevent the starting rotary table with drilling pressure; 3. When drilling into the loose sandstone formation, it is necessary to reduce the mechanical drilling speed properly to consolidate the hole wall of the open hole and prevent the casing from being trapped. 4. When drilling in directional drilling, check whether the dynamic drilling tool is functioning normally and should be tested when it is not connected to the drill. It is strictly prohibited to carry out the bit test operation on the wellhead to prevent damage to the cutting teeth; 5. If the drill bit is not drilled, the pump pressure will increase or decrease, the mechanical drilling speed will drop suddenly and the torque will increase. If there is no problem with the surface equipment, the drill should be checked.

　　3. When the drill bit is taken out of the box, the following should be board or rubber gasket. When unloading the drill bit, use the bit loader, and the torque can be tightened according to the corresponding thread size. 3 drill bit into the well to support and slow down, to the sealing well, when the hole is to be found, especially to slow down the speed of devolution, and pay attention to the anti-collision. 4. When the drill is under control, the drilling pressure should be controlled below 20KN and the speed is lower than 50 RPM. It is strictly forbidden to row the eyes and not recycle drilling fluid. When the drill is near the bottom of the well, the pump should be opened in advance. The drill bit is more than 0.5m above the bottom of the well. It should move slowly up and down and turn the drilling tool, fully circulating the drilling fluid. After cleaning the bottom of the well, it is necessary to calibrate the indicator and the bottom of the well after the pump pressure is normal. 6 well bottom molding, ordinary rotary drilling (1) carefully handle the cone bit. After confirming the bit contact with the bottom of the well, the parameters of 50 RPM and 5-10kn drilling pressure are used to grind the bottom of the well, and the penetration of 0.5 m - 1m7 per drill is about 300 to 400 meters for a short trip to prevent drilling and pulling out of the piston. At the end of the eight bit, the cutting teeth wear more and reduce the depth of the cutting teeth into the stratum, so the drilling speed can be improved properly.