(1) Auxiliary equipment and tools for the lifting process
The lifting process refers to the operations of lifting drilling tools and casing, placing and lifting the core tube, logging instruments and other purposes process. In core drilling, the lifting process is frequent and takes a long time (accounting for 20 to 60 of the total working hours). The longer the lifting and lowering process takes, the lower the overall drilling efficiency will be. Therefore, optimizing the machinery and tools used in the lifting process and realizing mechanization and automation of the lifting process are important measures to ensure safe production and improve drilling efficiency.
1. Drill pipe unscrewing equipment
Drill pipe unscrewing equipment is an accessory machine that is matched with the drilling rig and is used to unscrew drill pipes or drilling tools instead of manpower. There are three types of unscrewing equipment: mechanical, hydraulic and electric. The mechanical type is mainly matched with the old vertical shaft drilling rig and is rarely produced now. Hydraulic drill pipe unscrewing equipment is currently commonly used.
(1)NY-1 type pipe twisting machine
NY-1 type hydraulic pipe twisting machine consists of a twisting and unloading mechanism, an impact mechanism and a hydraulic system (Figure 2-28). Used to unscrew ordinary lock joint drill pipes with diameters of 42mm, 50mm and 60mm. When the system hydraulic pressure is 6MPa, the torque of unscrewing the pipe is 0.33kN·m; when the oil pressure reaches 8MPa, the unscrewing torque of the hydraulic cylinder is 0.44kN·m, the piston stroke of the hydraulic cylinder is 130mm, and the rotational speed of unscrewing the drill pipe is 75r/min.
Figure 2-28 NY-1 hydraulic pipe twisting machine
(2) SQ114/8 hydraulic pipe twisting power tongs
SQ114/8 hydraulic pipe twisting machine The pipe twisting power tong consists of the main tong, front guide rod, back tong, rear guide rod, suspension rod, hanging barrel, hydraulic motor, hydraulic reversing valve, shift handle, etc. (Figure 2-29), and is mainly used for rope retrieval. The main technical parameters of core drill pipe and small and medium diameter geological drilling casing are listed in Table 2-17.
Table 2-17 Main technical parameters of SQ114/8 hydraulic pipe twisting power tongs
Figure 2-29 SQ114/8 hydraulic pipe twisting power tongs
The main performance features of the SQ114/8 hydraulic pipe twisting power tong are: ① Easy to connect, can be connected with all geological drilling rigs, and can be equipped with a separate power station; ② Reliable clamping and unfastening, clamping the upsetting part of the drill pipe without slipping , does not bite the drill pipe; ③ The main backing tongs have good centering performance, float each other, and are integrally suspended, and can be swung sideways to remove the orifice; ④ The operation is simple, the reversing valve can be unscrewed, and the main backing tongs are clamped and synchronized synchronously Loosen; ⑤ Two-speed setting, which can realize quick unscrewing in high gear and high-torque unscrewing in low gear, and the torque can be set.
This hydraulic pipe twisting power tong is used in conjunction with a hydraulic vertical shaft drilling rig and a fully hydraulic power head drilling rig, and has been widely used in wireline coring drilling across the country.
2. Hole clamping device
The hole clamping device is used to clamp the drill pipe at the hole. Depending on the type of drill pipe being clamped, it is divided into ordinary clamps and wireline coring clamps. Ordinary clamps mostly use the fork type. When unscrewing the drill pipe, the fork is directly forked into the cut of the drill pipe and seated on the hole or the pipe twisting machine, which is more convenient to use. However, wireline coring drill pipes are internally and externally flat drill pipes. The joint wall is thin and incisions cannot be added. Therefore, slip type and ball clamps can only be used based on the wedge surface principle. Currently, Trojan clamps and hydraulic clamps are commonly used. holder.
(1) Trojan holder
The Trojan holder, also known as the foot-operated holder, is used to hold rope coring drill rods. It uses two eccentric seats to squeeze and clamp slips, and realizes automatic clamping by the gravity of the drill pipe. The greater the mass of the drill pipe in the hole, the greater the clamping force generated by the clamp. Slips should be replaced in time after wear to prevent the pipe from running out due to insufficient clamping. The Trojan-type clamp is shown in Figure 2-30.
Figure 2-30 Trojan clamp
(a) Self-weight Trojan type; (b) Light Trojan type
(2) Hydraulic clamp
Hydraulic clamps greatly improve workers’ labor intensity and increase safety production levels. A common hydraulic drill pipe holder is shown in Figure 2-31.
In deep hole drilling, the mass of the drill pipe in the hole is large. When selecting the hole clamping device, be sure to pay attention to the clamper having sufficient strength and clamping capacity to prevent slipping due to insufficient clamping force. Drilling accident. When the drilling depth is ≥1000m, self-weighted Trojan clamps and hydraulic, hydraulic/pneumatic clamps should be selected.
Figure 2-31 Hydraulic clamper
(a) Hydraulic clamper; (b) Pneumatic/hydraulic clamper
3. Drill pipe and casing suspension device
The process of lifting the drill pipe and casing is inseparable from the suspension device. The suspension device is mainly composed of traveling blocks, lifters, elevators, splints and other equipment ( Figure 2-32 to Figure 2-35), its strength and quality are directly related to the personal safety of workers and the safety in the hole.
Figure 2-32 Swimming pulley and swimming hook
Figure 2-33 Lifter
(a) Incision type; (b) Hand Rubbing type; (c) ball clamp type; (d) pole climbing type
Figure 2-34 Rope coring elevator
Figure 2-35 Splint
The following points should be noted in the configuration and selection of suspension devices:
1) Swimming pulleys include single wheels, double wheels and multiple wheels. Single and double wheels are generally used for shallow drilling, which can increase the drilling speed. After the drilling depth is ≥1000m, a multi-wheel traveling block should be selected based on the lifting capacity of the single rope of the drilling rig's hoisting system. The carrying capacity of the traveling block must be greater than or equal to 3 times the total gravity of the drilling tool at the hole depth.
2) The lifter is a tool that connects the drill pipe and the traveling block. The main types include hand-rubbing type, incision type, climbing pole type, ball card type, etc. The notch type is mostly used for ordinary drill pipes with locking joints, and the hand-rubbing type is used for rope coring drill pipes. When drilling deep holes, for the safety of raising and lowering the drill pipe, choose a drill pipe with a mushroom head and use a climbing rod or elevator type lifter. When selecting a lifting device, its lifting capacity must be greater than or equal to 2 times the total gravity of the drilling tool.
3) Elevators are mostly used for drill pipes with locking joints and casing lifting devices with large primary couplings. Elevators have high strength and a large lifting safety factor. The splint is mainly used for lifting casing with a mass of less than 10t. Its safety is poor and it is not suitable for deep hole drilling.
4. Faucet
The faucet is installed on the upper end of the active drill pipe and is connected to the water pump with a hose. Its function is to send the flushing fluid discharged from the mud pump into the inner hole of the drill pipe and into the hole, and to ensure that the high-pressure hose does not rotate when the active drill pipe rotates. In addition, the faucet also plays the role of suspending the drill pipe.
Faucets come in many forms, which are divided into shallow-hole faucets and deep-hole faucets according to their applicable hole depths; according to their different rotating parts, they can be divided into external-rotation types (shell-rotating types) And internal rotation type (heart tube rotation type); according to the number of channels of flushing fluid and medium, it can be divided into single channel and double channel forms.
The main faucet types are shown in Figure 2-36. Among them, small-diameter portable faucets are mainly suitable for shallow boreholes with a diameter of 1000m or less. They are characterized by small faucet volume, small core pipe water area, small water pressure resistance, low tensile strength, and are suitable for high-speed operation; high-pressure faucets and lifts The characteristics of the high-strength faucet are: larger volume, high tensile strength, good sealing performance, high water pressure resistance, and suitable for deep hole use; the dual-channel faucet can be used for multi-media forward and reverse circulation drilling. Compared with conventional faucets, it has more A side-entry circulating medium channel is used to introduce the circulating medium into the annulus between the inner and outer tubes of the double-walled drill pipe during reverse circulation drilling. In addition, there are also cable-type faucets used for cable-type measurement while drilling in directional drilling.
Figure 2-36 Main faucet types
(a) Small diameter faucet; (b) Portable faucet; (c) High-pressure faucet; (d) High-strength faucet; (e )Double-channel faucet
5. Drawworks
There are two main types of drawworks configured at the drilling site, cable drawworks for logging and directional drilling and rope coring drilling, salvage and placement of inner pipes (It can also be used as an in-hole storage inclinometer for transportation) with a steel cable winch. As shown in Figure 2-37.
Figure 2-37 Special drawworks for drilling sites
(a) Logging drawworks; (b) Rope coring drawworks
When selecting drawworks for drilling sites, the following requirements should be met: The following conditions of use: ① The power must meet the requirements of the hole depth and working conditions; ② The cable arranging capacity of the winch hub should be greater than the working hole depth requirements; ③ The winch should be equipped with a rope arranging and hole depth counter as much as possible; ④ It must be equipped with a lifting speed change mechanism.
(2) Mud purification and pulping equipment
During deep hole drilling construction, a large amount of cuttings and other solid matter mixed in the drilling fluid must be removed promptly and effectively for recirculation. Use mud to improve drilling efficiency, extend the service life of the machine tools in the hole, reduce costs, and prevent accidents.
Mud can be purified through three methods: sedimentation, mechanical separation and chemical treatment. The most commonly used method is mechanical separation, which uses mud purification equipment to forcefully remove drilling cuttings from the mud. Mud purification equipment mainly includes vibrating screens, hydrocyclone desanders, centrifugal separators, etc. Mud preparation equipment is mixers (Figure 2-38).
Figure 2-38 Mud purification and pulping equipment
(a) Vibrating screen; (b) Centrifuge; (c) Dual-action processor of vibrating screen and desander; (d) Mixer
1. Vibrating screen
The vibrating screen uses the vibration of the screen surface to promote the separation of slurry and solid particles and the separation between solid particles of different sizes. It is the slurry The first level of purification equipment in the purification system. The mud returned from the borehole first passes through a vibrating screen to remove coarse drill cuttings (solid particles of about 20 mesh).
Vibrating screens generally consist of the following parts: motor and belt transmission device, screen body and screen mesh, elastic support (or suspension) device, vibrator, base or frame, overflow tank and slurry storage Boxes etc. After the vibrator works, it drives the screen surface to vibrate in one direction or in multiple directions. When the mud flows from the overflow tank to the screen surface, relative movement and vibration occur between the slurry and the solid particles in the slurry and the vibrating screen surface. This movement promotes the separation process of liquid and solid particles. The slurry and drill cuttings smaller than the screen hole flow to the slurry storage tank below through the screen surface, while the coarse drill cuttings larger than the screen hole will slide downward along the inclined screen surface. If multiple layers of screens with different specifications are used (small mesh screen at the top and large mesh at the bottom), the drill cuttings of different particle sizes will be separated and slide down along different screen surfaces.
There are two basic types of vibrating screens used in China: one is a unidirectional vibrating screen, which uses a biaxially symmetrical vibrator to drive the screen surface to vibrate in one direction along its long axis; the other is a unidirectional vibrating screen. The first type is a multi-directional vibrating screen. The power machine drives the eccentric shaft to rotate. The screen body, screen mesh and eccentric shaft are connected into one, and the screen surface vibrates in multiple directions.
The vibrating screen mesh is usually woven with stainless steel wire. The mesh size is the main factor that affects the solid phase removal effect. Its specifications include: 30 mesh, 40 mesh, 60 mesh, 80 mesh, 100 mesh, 120 mesh, 140 mesh, 160 mesh and 200 mesh. There are two types of mesh shapes: square and rectangular. The latter is not easy to block.
2. Hydrocyclone Desander
Hydrocyclone Desander (Figure 2-39) uses centrifugal force to separate solid particles in the slurry. In the mud purification system, it is connected after the vibrating screen to remove drill cuttings finer than 20 to 30 mesh (generally removing particles of 70 to 200 μm) from the mud to achieve the second level of mud purification. The hydrocyclone desander is a cylindrical device with a simple structure and no moving parts. The upper part is cylindrical and the lower part is an inverted cone. In addition, there are tangential slurry inlet pipes, overflow pipes and underflow holes (or sand discharge holes).
Figure 2-39 Principle of cyclone desander
(a) Cyclone desander; (b) Double helix model; (c) Two-dimensional traces representing each Flow pattern
1—Slurry inlet pipe; 2—Overflow pipe; 3—Cylinder; 4—Cone; 5—Sand discharge nozzle; 6—Short-circuit flow; 7—Circulating flow; 8— Internal swirl flow; 9-external swirl flow; 10-air column; 11-axial zero speed surface; 12-discharge external swirl flow
The mud with a certain pressure sent by the sand pump is passed through the The slurry pipe enters the upper part of the cyclone along the tangential direction of the cylinder. Due to the inertia of the liquid flow movement, the guidance of the circular cylinder wall and the gravity of the liquid, the mud rotates in the cylinder and forms a spiral liquid flow that continuously moves downward. The solid particles in the liquid flow are separated from the slurry by centrifugal forces of varying sizes due to their different masses, and are thrown towards the cylinder wall. And driven by the rotating liquid flow and its own weight, it slides down along the cylinder wall in a spiral trajectory. When the spiral liquid flow descends to the cone part, the circumferential linear velocity of the liquid flow continues to accelerate due to the continuous reduction of the flow cross section. Under the influence of high-speed swirling flow, the air in the cylinder is concentrated near the axis, and due to the entrainment of the liquid flow, a columnar negative pressure zone is formed around the axis. In this way, when the spiral liquid flows to the lower part of the large cone (after most of the drill cuttings are separated, it is relatively clean mud), it changes direction under the action of negative pressure on the axis, forming an upward vortex that rotates in the same direction and presses along the axis. It rises in a spiral shape and is discharged from the overflow pipe. Relying on the two downward and upward swirling motions in the cyclone, the effective separation and reverse collection of slurry and cuttings are achieved.
The specifications of the cyclone desander are usually expressed by the diameter of the upper cylinder of the desander (unit: in, 1in=0.0254m), such as: 2in, 3in, 4in, 5in, 6in, 7in, 8in ,10in,12in. Generally speaking, the larger the size of the cyclone, the larger the size of the solid particles it separates and the amount of mud processed per unit time.
The structure and working principle of the desander are the same as those of the desander. The difference lies in the structural size, the particle size of solid particles removed from drill cuttings and the ability to process mud. The size of the desilter is small, usually used to separate solid particles of 15 to 40 μm, and the mud processing capacity is also small. Therefore, multiple desilters are often used in conjunction with the desander.
The inner wall of the cylinder of the desander and desilter is easily abraded by the high-speed liquid flow of solid particles. In order to improve its wear resistance, it can be made of white cast iron, carbon steel lined with wear-resistant rubber or other wear-resistant materials.
3. Centrifugal separator
After passing through the desander and desilter, if the solid content particles in the mud still cannot meet the drilling requirements, the desilter must be removed again. The treated mud is pumped into a centrifuge for separation, which can separate the fine cuttings and sand in the mud. Generally, it can remove harmful solid phases above 2 μm, remove excess colloids in the drilling fluid, control the mud viscosity, and recover barite.
Separators include sedimentation type, screen drum type, hydraulic turbine type, stacked disc type and other types.
Generally, mud purification equipment for core drilling only includes vibrating screens, cyclone desanders or desilters, sand pumps and mud tanks, and centrifuges are rarely used. Because the particle size of the cuttings produced during coring drilling is very small, taking diamond coring drilling as an example, the particle size of cuttings above 70 is <0.1mm, so usually only a desander or desilter is used, supplemented by appropriate chemicals. Treatment agents (such as flocculants, etc.) can meet the mud purification requirements.
4. Mud mixer
The equipment for preparing mud mainly includes mud mixer and hydraulic mixer. The capacity of the horizontal mud mixer equipped on site is generally 0.3~0.5m3, the vertical type is 0.5~1m3, and the mixing speed is generally 80~100r/min. Hydraulic mixers are mostly used for cement mixing for well cementing and hole sealing.