Casing pipes are used for keeping the walls of OCTG wells rigid during the extraction of Petroleum, Natural Gas, Hot Water, Vapor as well as Salt and similar solid materials.
Range of Steel materials of Casings are defined from low strength to high as H40, J55, K55, N80-Q, M65, L80, C90, C95, T95, P110 and Q125 which are manufactured according to API Standards.
Depending on the depth of well and casing string order, pipe diameters, wall thicknesses, steel material and thread type selection are performed and high security coefficients are targeted. Diameters of casing pipes vary between 4-1/2” (114,3 mm) and 20” (508,0 mm) according to API standards.
Casing pipes are connected to each other by means of screwing with couplings, like other well pipes and driven downwards. Mostly API (American Petroleum Institute) standards are applicable during manufacturing of these pipes. In connection with this standard, generally 3 different types of threads are used on casing pipes. These threads are known as STC (Short Thread Casing), LTC (Long Thread Casing), BTC (Buttress Thread Casing) and some special types machined conforming to API 5B standard.
These pipes which are manufactured according to API 5CT standard in order to be used on hot water wells, petroleum and natural gas wells are shipped to our mill as green pipes with plain ends. Pipes are furnished with an upset and thread cutting process conforming to API 5B standard as well as processes of cutting slots.
When liquid products, which are aimed to be extracted from underground tubing pipes, also known as production pipes with smaller diameters than casings are driven down to the well inside the casing pipes. Especially during petroleum production, petroleum at the bottom of the well is excavated to the ground through tubing pipes by means of a horsehead pump attached to the upper side of the well. It works continuously up and down movement on ground.
Tubing pipe diameters are ranging between 1,05” (Ø26,7 mm) to 4-1/2” (Ø114,3 mm) according to API standard. Same steel materials as casings can also be used on these pipes.
In connection with the loads, to be carried according to the working depths of the tubing pipes, in order to strengthen thread ends upsetting might be applied to the ends of the pipes. Thicker threads might be cut to the ends of pipes with upset with more strength. Tubing pipes are divided into two groups of non-upset end (NU) without upset type and with Externally Upset End (EU) type.
Drill pipes are used for drilling holes downward to reach the media underground with drilling bits in front end of it. In order to have a stable and healthy drilling operation few intermediate connection parts and thick walled pipes for weighting are attached between auger and drill pipes.
Drill pipes are composed of three sections, main pipe body with box and pin fixed to ends of this body. Box and pin are attached to the body pipe with various methods, mostly as Frictional Welding, Screw and Filling welded and tight passing. The most acceptable method among these methods is most recently developed Frictional Welding according to international standards.