Ipayipi elikhethekile le-Petroleum lisetshenziselwa ikakhulukazi ukumba imithombo kawoyela negesi kanye nokuthuthwa kukawoyela negesi.Kuhlanganisa ipayipi lokumba i-petroleum, i-petroleum casing, nepayipi lokuncelisa.Amafuthaipayipi lokubhobozaisetshenziswa kakhulu ukuxhuma ikhola yokubhoboza kanye ne-drill bit futhi idlulise amandla okubhola.Igobolondo likawoyela lisetshenziselwa ikakhulukazi ukusekela udonga lwe-borehole ngesikhathi nangemuva kokumba ukuze kuqinisekiswe ukusebenza okuvamile kwawo wonke umthombo kawoyela phakathi nangemuva kokumba.Ipayipi lokumunca ngokuyinhloko lithutha uwoyela negesi ukusuka phansi komthombo ukuya phezulu.

Isikhwama sikawoyela siyindlela yokuphila yokugcina ukusebenza komthombo kawoyela.Ngenxa yezimo ezihlukene zokwakheka komhlaba kanye nesimo esiyinkimbinkimbi samandla omgodi ophansi, imiphumela ehlanganisiwe yokushuba, ukucindezelwa kanye nokucindezeleka okuguquguqukayo emzimbeni wepayipi kubeka phambili izidingo eziphakeme zekhwalithi yekesi ngokwalo.Uma i-casing ngokwayo ilimele ngenxa yesizathu esithile, ingase iholele ekunciphiseni ukukhiqizwa kwawo wonke umthombo noma ngisho ne-scrap.

Ngokusho kwamandla ensimbi ngokwayo, i-casing ingahlukaniswa ngamamaki ensimbi ahlukene, okuyi-J55, K55.I-N80, L80, C90, T95, P110, Q125.V150 nokunye.Izimo ezihlukene zemithombo nokujula nakho kusebenzisa amamaki ensimbi ahlukene.Ezimweni ezigqwalile, i-casing ngokwayo nayo iyadingeka ukuze ibe nokuvikeleka kokugqwala.Lapho izimo ze-geological ziyinkimbinkimbi, i-casing nayo iyadingeka ukuze kube nokusebenza okulwa nokugoqa.