The selection of Wireline Diamond core Bit should pay attention to the compatibility of the Wireline Diamond core Bit and the formation. It is necessary to select the appropriate drill bit type and reasonable drilling procedures based on the mechanical and physical characteristics of the rock formation to be drilled, based on the difficult formation to drill, taking into account the easy formation to drill, and taking into account the protection of the drill bit and extending the life of the drill bit, so as to achieve the purpose of ensuring quality, improving efficiency and reducing costs.
2.3 Queuing of drill bits
The characteristic of Wireline Diamond core Bit is that they can work continuously at the bottom of the hole for a long time. Only when the drill bit is worn to a certain extent, the drill is lifted for inspection and replacement, so it is very important to queue the drill bits. In order to keep the hole diameter consistent and give full play to the drill bit efficiency, all drill bits and reamer inner and outer diameters should be measured accurately before each drilling and queued in groups for use in turn.
First use a Wireline Diamond core Bit with a large outer diameter and a small inner diameter, and then use a drill bit with a small outer diameter and a large inner diameter, so that the replaced new drill bit can be smoothly lowered to the bottom of the hole to avoid drilling accidents and core blockage. If you do not pay attention to the queueing of drill bits, such as putting a drill bit with a large outer diameter and a small inner diameter at the end, it is easy to expand the large hole section, and the replaced new drill bit cannot reach the bottom of the hole, increasing the drilling workload, and even damaging the drill bit or causing an accident in the hole.
2.4 Prevention of drilling burn accidents
In addition to selecting appropriate drill bits, flushing fluids and reasonable operating procedures, the following methods are generally used in practice to prevent drilling burn accidents:
The core should be salvaged immediately if it is blocked; according to the nature of the drilling formation, the reasonable drilling time should be controlled; before each drilling, especially when drilling holes in broken and easily collapsed formations, the pump volume should be appropriately increased to flush the bottom of the hole; a variable pump should be used and equipped with a sensitive and reliable pump pressure gauge to ensure the supply of flushing fluid and pay attention to the pressure changes;
When lifting the drill, the wear of the water tank and the water outlet should be checked, and the water The water path that does not meet the requirements should be repaired or replaced, and the depth of the water outlet should be kept at about 4mm; design a reasonable water path according to the characteristics of the Wireline Diamond core Bit wall thickness, and improve the drill bit structure. In practice, the cooling conditions of the drill bit are improved by appropriately increasing the number of water outlets, reducing the thickness of the tire body and the bottom lip area to extend its life. The number of water outlets should be increased to 10 to 12, and 1 to 3 water holes should be set in the middle of the tire block to improve its cooling conditions and prevent early burns. Once the water tank in the drill bit is worn or the core is blocked, the flushing fluid can flow out of the water hole, which is more beneficial to prevent drill burning.
