Five commonly used wellhead tools-slip 2.0

Slips

The slips is a tool used to hold and suspend the drill string in the well during the drilling process. The slip is mainly composed of the slip body, the insert slip, the handle and the connecting piece. watt.

1.Type of slips

• We look at the function it is divided into: drill pipe slips, drill collar slips and casing slips.
• According to the structure, it is divided into: three-piece, four-piece slips and long and short slips.
• According to the operation mode, it is divided into: power slip and manual slip.

2.Three-piece slip

The three-piece slip is composed of three fan-shaped slip bodies. The three slip bodies are hinged to each other with hinge pins, but they are not closed. The drill string can enter and exit freely. Each slip body has a circumferential dovetail groove and is equipped with Liners and kava teeth. By changing the liner and slip teeth, slips can be used for different drill strings to a limited extent.

Length specification

Drill pipe safety clamp(Varco) with SDS, SDML, SDXL three length specifications.

• SDS is a short slip, size range: 2-3/8″ to 4 ½”
• SDML is a medium slip, size range: 2-3/8″ to 5 ½”
• SDXL is a medium slip size range: 3-1/2″ to 5 ½”

The clamp hug the drill string and sit in the center of the turntable, the slip teeth fit tightly with the drill string, and the drill string is stuck. When the clamps are lifted, because the tooth pins of the clamps are slightly inclined upward, the surface of the teeth of the clamps is easy to disengage the drill string, and the drill string will lift and lower when lift the clamps In this form there are 2-1/2″, 4-1/2″ clamps and 5″, 7″ clamps.

When the slips are required to bear a large load, the three-piece slip with a large angle can be used. Its structural characteristics are that the angle surrounding the drill string is large, and the teeth of the slip are lengthened, which can provide a large degree of cohesion to the drill string. , The cohesion length is long, and it can bear heavy and large loads, which is suitable for deep wells. Because the slips are inserted into the slip body discontinuously, it will not cause slippage when clamping the drill string. The of this kind of slips’ disadvantage are easy to fall into the well during operation. Therefore, this kind of slip with watt-hours, better materials and higher manufacturing techniques to improve chip resistance.

3.Multi-piece slips (casing slips)

Such multi-piece slips for large diameter loads. Each slip body is hinged to each other with connecting pins, but not closed. Each slip body has a circumferential dovetail groove, and each groove is equipped with an integral slip tooth, with a total of eleven pieces.

4.Drill collar Slips

Drilling slip (Varco) models are divided into: DCS-S, DCS-R, DCS-L three

• DCS-S size range: 3″ to 4″, 4″ to 4-7/8″;
• DCS-R size range: 4½” to 6”, 5-1/2” to 7”;
• DCS-L Size Range: 6-3/4″ to 14″;

5.Safety clamp

Safety slips are used in conjunction with slips when tripping drill collars, coring barrels and large diameter pipes to prevent drilling tools from slipping into the well. A plurality of slip bodies are connected into one body through pin holes and pins, and the two ends are connected with the lead screw through chain pins to form an adjustable slip. Changing the number of teeth plate sleeves of the safety slip can adapt to different sizes of drill collars and pipe strings.

• For drill collars without shoulders, use safety Safety Clamps
• The safety slip is at least composed of a tooth plate sleeve, a slip tooth, a spring, an adjusting screw, a nut, a handle and a connecting rod.
• When the safety slip is in use, after tightening the nut, tap each pin with a hammer, so that each slip tooth fully contacts the drill collar in the circumferential direction, so as to play a safety protection role.
• The safety slip is 5cm away from the slip.

6.Check before use

• 1) When the slip teeth wear out 1/4 of the original height, the new tooth plate should be replaced;
• 2) If the new tooth plate is installed in the tooth plate groove, if it shakes, the slip body will be scrapped;
• 3) Each hinge part is flexible and free, the parts are complete, and it can be replaced in time after wear;
• 4) When the slip is opened, its opening shall not be less than the nominal size of the drilling tool;
• 5) After installing the new dental plate, at least 80% of the teeth can contact the drill body;

7.Precautions

• (1) The appropriate slip size should be selected according to the drilling tools in the well.
• (2) Check the sharpness of the Safety Clamps, whether they are loose or reversed, whether they are clean, whether the screws and cotter pins are complete and tight, and the connecting shaft pins should rotate flexibly.
• (3) After the well depth of 1000 meters, double elevators must be used for drilling and drilling, and it is forbidden to use Safety Clamps and elevators for drilling and drilling (land)
• ⑷ When tripping the drill collar, Safety Clamps should be used together with safetySafety Clamps. The slip is 50cm away from the end face of the female buckle, and the safety slip is 5cm away from the slip.
• ⑸ Wellhead operators should stand outside the rotation range of Safety Clamps to prevent injury to their legs and feet during rotation.

8.Maintenance

• (1) The use of drill pipe slips as drill collar slips is prohibited.
• (2) Before use, check whether each rotating part is flexible and whether there is any jamming phenomenon.
• (3) Before use, check the tapered surface of the slip body and the slip teeth for plastic deformation and excessive wear. If there is any, please replace it in time.
• (4) Do not overload during use, and do not choose non-matching models.
• (5) Avoid lifting the pipe string too fast during use, which will cause the slips to be broken or make deep scratches on the surface of the pipe string. It is forbidden to use the elevator with overload and throw the slips during rapid drilling to cause impact.
• (6) After use, clean the slips, the italics of slips should be kept clean, and often lubricated with oil, the exposed surface should be coated with anti-rust grease, and placed in a ventilated and dry place indoors.
• (7) The slips should be placed in sets according to the specified number, and should not be arbitrarily reduced.
• (8) Replace wearing parts in time.
• (9) When working in the field, all parts should be kept clean.