In the middle and late stages of oilfield development, as the production time lengthens and the number of operations and workovers increases, casing damage will occur one after another. After the event of damage, prompt repair is imperative to avoid any potential underground accidents.
① Inspection and Measurement
The main contents of casing inspection include changes in its inner diameter, quality, wall thickness, inner wall condition, etc. In addition, the position of couplings must be checked and determined.
② Repair
The deformed sleeve can be repaired by plastic surgery.
(1) Pear shaped shaper (also known as tube expander)
Lower the pipe expander to the deformed well section, and gradually expand the deformed part by relying on the swelling force of the drilling tool. The lateral distance that can be expanded each time is only 1~2mm, and the tool is replaced many times.
(2) Casing shaper
This tool is used more and is a better shaper.
It is a special tool used to repair flattening, denting and other deformations in a well to restore it to its normal condition.
It consists of an eccentric shaft equipped with upper, middle and lower rollers and a cone head, as well as balls and screw plugs for fixing the cone head. Lower this tool onto the deformed part, rotate it and apply appropriate pressure to force the cone head and roller to squeeze the deformed pipe wall outwards with a large lateral force to reach normal diameter and roundness.
Scrapers are used to remove any deposits, irregularities or burrs inside oil well to remove obstacles for future operations.
③ Casing subsidy
Subsidy measures can be used to repair wells with perforated or cracked casing s. Its inner diameter should be reduced by about 10 mm. One construction can be subsidized by 10 - 70m. The subsidized size is from Φ 60mm to Φ 273mm, and the subsidized depth is from 5m to 3900m.
(1) Subsidy management
The subsidy pipe is generally a seamless steel pipe with a wall thickness of 3mm, with large corrugations in the longitudinal direction, and the pipe is wrapped with a thickness of 0.12 mm of glass fiber cloth and glued with epoxy resin. Each pipe is 3m long. When in use, the length of the downcomer can be welded on site according to design requirements, and the outer wall is coated with epoxy resin before downcomer.
(2) Subsidy tools
It mainly consists of centralizer, sliding sleeve, upper hammer, hydraulic anchor, piston barrel, fixed piston, piston, upper head, piston rod, tension tube and tube expander.
④ Casing inboard drilling is mainly used to repair oil wells with serious faults underground. It is difficult to treat such complex wells with ordinary methods. The casing sidetracking technology must be used to repair dead wells and improve oil well utilization.
It is to fix a dipstick at a certain depth in the oil and water well, use the bevel deflection and deflection guide effect, use a milling cone to open a window on the side, drill a new borehole from the window and then run the liner for cementing. A complete process. Inboard drilling technology is the application of directional drilling technology in oil and water well overhauling.
The main tools include whipholder, whipfeeder, milling cone, drill bit, release joint, cementing rubber plug, etc.
Vigor will provide you with a reliable solution, Please contact us at info@vigorpetroleum.com.
