Dickens

Original title: Have you ever used these fishing methods of drill pipe and drill bit? In the process of pile foundation construction with rotary excavator big bore, the accidents of hole collapse, drill burying and drill holding occur from time to time, but the causes, accident conditions and site conditions of rotary excavator accidents are not the same, so the measures taken are not the same, sometimes several treatment methods may be needed. Xiaobian focuses on describing the treatment method of buried drill, and describes the treatment tools in detail, hoping to communicate with peers. After the accident of burying or holding the drill bit, the mud performance shall be adjusted in time to prevent the accident from continuing to expand, and the causes shall be analyzed in time to take corresponding measures so as not to miss the best treatment opportunity. The treatment of burying drill can be summarized as methods and steps such as “clearing, penetrating, jacking, blasting, expanding, fishing, smashing and digging”. I. Treatment of Sediment “Clear” means to clear slag and wash holes. Slag removal can be carried out by positive and negative circulation,dhd drill bit, high pressure jet or well washing pipe air compressor. Sludge removal shall be carried out according to the mud quality of the formation and the hole cleaning equipment used, so as to avoid the occurrence of secondary hole collapse in the process of drilling. Use the air compressor to wash the hole. II. Fishing of drill pipe bit (1) In some cases, the key to deal with the accident of burying the drill bit is to dredge the channel between the bottom of the hole and the upper part of the drill bit, so that the bottom and the upper part of the drill bit form a communicating vessel to avoid the piston effect, that is, “through”. In order to form a communicating vessel,fastest dth hammer, several holes deeper than the accident hole are generally drilled at the edge of the hole, and high-pressure rotary spraying is used for swing spraying. It is used to form a passage, rotate the power head and increase the pulling force of the main rope at the same time, and it is possible to lift the drill rod and the drill bit together. Some treatment schemes adopt the combination of reverse circulation drilling rig and reaming bit. (2) “Jacking” means jacking the drill pipe with a Jack, which is the most commonly used force method to deal with buried drill. A solid platform shall be provided for the use of the Jack, and the Jack force application plate shall be welded on the drill pipe. Weld the 3cm ribbed plate with the drill rod, firmly weld the top plate with the ribbed plate and the drill rod, and connect the two top plates. The I-beam shall be 60x100cm and connected with connecting plate. The Jack control system shall be interlocked to pressurize. Generally, the limit load that the snap ring or straight pin connected to the upper part of the drill pipe can bear is about 180kN. After the pressure is increased to 150kN by the Jack linkage, the pressure should be gradually increased, and it should be stagnated for about 1 hour after every 3 to 5kN increase, waiting for the creep effect of the soil layer. Turn the power head while applying pressure. There are several possible results of using the Jack: first, DHD Drill bit ,mining dth bit, the drill bit and the drill rod are all ejected; second, the top cover or bucket gate of the drill bit is damaged, and the drill rod and the damaged drill bit are ejected; third, the snap ring or straight pin of the inner rod of the drill pipe is broken, and the inner rod and the bit are left in the hole; fourth, the drill pipe is broken from the old crack. ? A portion of the drill pipe and bit remains in the hole. (3) “Blasting” refers to hole bottom blasting. If the drill bit cannot be lifted after hole washing, the drill bit can be damaged by explosive positioning blasting, and the drill pipe can be lifted. Generally, the foundation pile holes treated by this method are close to the design depth, which can meet the bearing capacity requirements after design verification, and can be directly poured after blasting. (4) “Reaming” refers to reaming with a reaming bit about 10 cm larger than the drill bit to below the drill bit bucket door, and then fishing the drill pipe bit. The reaming bit can be modified by using a casing with a diameter 10 cm smaller than the original casing. (5) The force method of “sleeve, clamp and hook” can be used to salvage the drill bit or drill pipe of the rotary excavator. If the inner core of the drill pipe is broken, the drill pipe and the drilling bucket are left in the hole. After reaming and cleaning the hole, the diver can cover the drill pipe and drilling tool. When the buried depth is shallow, the drill rod can also be covered with a steel bar support. If the drill rod is buried deeply, after reaming and clearing the sediment, it can be salvaged with a pallet Fisher. When the sediment is thick, it can also be made into a looper. The elevator is fixed on three sections of drill rod with a self-made steel pin, and the pot bottom Fisher is also fixed on the same section of drill rod. The height of the straight wall of the Fisher shall be greater than the height of one end of the drill bit, so as to ensure that the wire rope welded in it can be cleaned in place. During slag removal, the wire rope sling can be fixed on the power head to ensure the synchronization of the rope sling and the drill pipe. When the ordinary drill bit is buried shallowly, the force of the lower hook can also be used. The welded rigid rod can be used to directly hook the beam of the buried drill bucket and lift the drill bit. (6) If the depth after blasting can not meet the requirements or the drill bit is broken in the hole, the percussion drill can be used to smash the damaged drill bit and carry out percussion drilling to finish the hole.
(7) In some areas, the water level is deep and the buried depth of the drill pipe is shallow, so the buried drill can be treated by digging under the ground. The size of the hole dug manually should be about 20cm larger than the hole diameter. Finally, the circumference of the drill bit can be hollowed out with Luoyang shovel, so that the drill bit can be dug out smoothly. As a basic distributor of XCMG, Nanjing Infinite has sold various series and models of rotary drilling rigs of XCMG to customers in Jiangsu, Zhejiang, Shandong, Fujian, Sichuan and other regions, and has served in the construction of Lianyungang-Xuzhou high-speed railway, Anjiu high-speed railway, Weilai high-speed railway and various piles. At the same time, it has more than 50 sets of self-owned equipment, 220, 280,down the hole bit, 360, 400 and other types of rotary drilling rigs for rent, and the leasing business is all over the country. Return to Sohu to see more Responsible Editor:. wt-dthtools.com