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Construction Introduction of LM-200 Reverse Drilling Rig
Source: xe1x.com Author: admin Date: 2019-03-05 14:51 heat:
Construction Introduction of LM-200 Reverse Drilling Rig
1 Construction layout
1.1 Cooling cycle system of reverse well drilling rig
The cooling circulation system of the reverse well drilling rig is composed of a well washing pump (mud pump), a pool and a ditch. A 5 m3 pool is set 15 m away from the foundation of the reverse well rig, and a partition wall is set in the middle of the pool to divide the pool into a clear pool and a sedimentation tank. The concrete foundation and the pool are connected by a ditch, and the return water and fine sand appearing in the construction of the pilot hole flow back to the sedimentation tank along this ditch. The well washing pump is arranged between the rig truck and the pool. The specific arrangement is shown in Figure 1.
1.2 Installation of the backtrack drilling rig transport track
In order to facilitate the positioning and positioning of the back-drilling rig, a transport track is installed on the ground in the unloading part of the cave. The track gauge is 60 cm, the track is a light rail of 24 kg / m, the sleepers are 10 cm ¡Á 10 cm square wood, and the spacing is 50 cm / root. .
1.3 Installation foundation of the reverse well rig
The reverse drilling rig is installed at the intersection of the flat section and the deviated well, and the drilled hole from the host matches the extension of the centerline of the deviated well. The operation truck and the pump truck are parked in the blind hole after the expansion and excavation in order, and the operation truck has a safety distance of more than 1 m from the drilling hole. The foundation is poured in C20 concrete in two phases.The foundation is formed in the first phase and the anchor bolt pit of the backwell drilling rig is reserved. After the standby body is in place and the preliminary calibration is performed, the second phase concrete is backfilled to ensure that the backwell rig is firmly connected to the foundation. No shift occurs.
2 Construction procedure of reverse rig
Foundation pouring (Phase I with circulating pool) → Backhole drilling rig installation (including high-pressure wash pump), initial positioning φ 216 mm pilot hole construction → Drill bit exposed at a predetermined depth (if no exposure is expanded, find a bit) → Construction of hole drill bit installation platform → Reaming bit lifting → Reaming bit installation → Installation platform withdrawal → φ1 200 reaming construction → Reaming bit disassembly → Reverse drilling rig removal.
3 Construction process and method
3.1 Installation of a reverse rig
The reverse well drilling rig uses a flat-bed truck with an actual load capacity of more than 10 t, the length of the cargo box should not exceed 5.5 m, and the height above the ground should not exceed 1.2 m.
3.2φ216 mm pilot hole construction
The key to the construction of the backdrilling rig is the pilot hole drilling quality. Whether the final pilot hole can be drilled. The deviation error after drilling cannot be detected and controlled in the middle after drilling. You can only rely on experience to implement different main and auxiliary pump working pressures, speeds and speeds. Assemble a stable drill pipe in time for control. The drill pipe of the reverse well drilling rig is divided into ordinary drill pipe (1 m) and stable drill pipe (0.5 m) .The difference is that the latter has more uniformly distributed four 3 cm thick steel ribs than the former. Prevent the drill rod from rotating with the increase of the depth to produce excessive bending and swing, play a stable role, and protect the contact between the drill rod and the hole wall. The installation method of the stable drill pipe used is as follows: one must be added when drilling 2 m, one is added when drilling 8-10 m, and one is added every 20 m. The above method is more reasonable and secure. When the drill pipe is installed, it is generally operated with a small power provided by the auxiliary pump. The strength between the drill pipe wire fasteners is moderate, and the too tight may easily damage the wire fasteners, and the loose drill pipe may easily fall off. In order to facilitate the disassembly of the drill pipe, a small amount of No. 10 lead wire can be added to the wire buckle before the drill pipe is socketed. When the pilot hole starts construction, the auxiliary pump is generally used to provide a small and uniform power to prevent the peripheral wall of the orifice from being difficult to form due to excessive vibration and cracking. The empirical data of the working pressure of the main and auxiliary pumps under different surrounding rock types and different drilling depths are shown in Table 1.
.3φ1 200 mm reaming construction
When the reaming is started, the surrounding rock is generally damaged, and it is difficult to uniformly stress the drill's periphery. Therefore, the auxiliary pump is used to provide smaller and uniform power, and the footage is slower, controlled at 10 cm / h to prevent the drill bit from being eccentrically stressed and twisted. In the drilling construction, a relatively stable water supply is required to enable the tool to be water-cooled, and the water supply is required to be not less than 7.8 m3 / h. During the reaming construction, special attention should be paid to the proper placement of the drill pipe slips and their intactness during the disassembly of the drill pipe, so as to avoid sudden breakage of the slips and cause the reaming drill bit and drill pipe to fall off. The empirical data of the working pressure of the reverse well drilling rig under various conditions is shown in Table 1.
4 Human resources allocation
During the construction of the guide hole and reaming of the inclined shaft, the site human resources are configured as follows: the operation team consists of 6 people, two people perform three shifts, and six of them have three mechanical technicians. Another mechanical worker has a long-term follow-up service and conducts on-site guidance in a timely manner.
The application of reverse boring rigs to long inclined shafts has a bright future in the future application of hydropower engineering construction, especially in terms of ensuring construction safety. This method is worthy of reference and promotion.
(1) The working principle of the reverse well drilling rig is relatively advanced, which can be applied to the construction of inclined (vertical) wells with large inclination and long depths. Compared with other guide shaft construction methods, it has certain schedule advantages and obvious safety advantages;
(2) Special attention should be paid to the construction method when installing and disassembling the drill pipe. The pressure of the drill should be moderate and uniform to prevent the drill pipe from falling off and causing difficult engineering accidents.
(3) Pay attention to the drilling speed during construction, and do not blindly pursue high footage, otherwise it will easily lead to the high deviation of the pilot hole and it is difficult to control and even twist the drill pipe;
(4) As far as the existing performance is concerned, the LM-200 reverse well drilling rig is suitable for a depth below 150 m, can be penetrated at one time, and has a sufficient installation working surface in the construction of inclined wells.
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