Casing is the steel pipe that supports the wall of an oil and gas well. Depending on the drilling depth and geological conditions, each well with multiple
CASING should be used. The cement used to cement the casing after it has been run should be used. Unlike
TUBING and
DRILL PIPE, it cannot be reused. It's a disposable consumable. As a result, casing consumption accounts for more than 70% of all well
Tubing. Casing can be divided into conduit casing, surface casing, technical casing and reservoir casing according to service conditions.
Guide sleeve: mainly used for Marine and desert drilling, separation of seawater and sand, to ensure the smooth drilling. The main specifications of this casing are: Φ762 mm (30in) x 25.4mm, ∮762 mm (30in) x 19.06mm.
(2) Surface casing: mainly used for bedrock drilling in soft strata. In order to seal this part of the formation without collapse, surface casing is needed to seal it. Main specifications of surface casing :508mm (20in), 406.4mm (16in), 339.73mm (13-3/8in), 273.05mm (10-3/4in), 244.48mm (9-5/9in), etc. The depth of pipeline laying depends on the depth of soft strata, generally 80~1500m. Its withstand external pressure and internal pressure are not big, generally using K55 steel grade or N80 steel grade.
③ technical casing
Technical casing is used in the drilling process in complex formations. When complex parts such as collapse layer, oil layer, gas layer, water layer, leakage layer and salt gypsum layer are encountered, technical casing is needed to seal, otherwise drilling operation cannot be carried out. Some Wells are deep and complex, with Wells several kilometers deep. This deep well requires multiple technical casing, which requires high mechanical and sealing performance. The grade of steel used is also very high. In addition to K55, N80 and P110 steel are used more. Some deep Wells also use non-API steel grades Q125 or higher, such as V150. The main specifications of technical casing are 339.73mm (13-3/8in), 273.05mm (10-3/4in), 244.48mm (9-5/8in), 219.08mm (8-5/8in), 193.68mm (7-5/8in) and 177.8mm (7in), etc.
(4) Reservoir casing
When drilling to the target zone (oil and gas bearing zone), the oil casing should be used to seal the oil and gas reservoir and the upper exposed formation, and the oil reservoir is in the oil casing pipe. Reservoir casing has the deepest running depth among all kinds of casing and requires the highest mechanical and sealing performance. The steel used is K55, N80, P110, Q125, V150 and so on. The main casing sizes are 177.8mm (7in.), 168.28mm (6-5/8in.), 139.7mm (5-1/2in.), 127mm (5in.), and 114.3mm (4-1/2in.).
ESASTSUN OILFIELD EQUIPMENT MANUFACTURING (CAMBODIA) CO., LTD