Mapaipi apadera amafuta amagwiritsidwa ntchito makamaka pobowola zitsime zamafuta ndi gasi komanso kunyamula mafuta ndi gasi. Zimaphatikizapo chitoliro chobowola mafuta, chotengera chamafuta, ndi chitoliro chopopera mafuta. Chitoliro chobowola mafuta chimagwiritsidwa ntchito makamaka kulumikiza makola obowola ndi zitsulo zobowola ndikutumiza mphamvu zobowola. Chophimba chamafuta chimagwiritsidwa ntchito kuthandizira khoma la chitsime panthawi yobowola komanso mukamaliza bwino kuti zitsimikizire kuti kubowola komanso kugwira ntchito kwabwino kwa chitsime chonse chamafuta mukamaliza. Chitoliro chopopera makamaka chimanyamula mafuta ndi gasi kuchokera pansi pa chitsime chamafuta kupita pamwamba.

Kusungirako mafuta ndiye njira yopulumutsira zitsime zamafuta. Chifukwa chamitundu yosiyanasiyana yazachilengedwe komanso kupsinjika kovutirapo kutsika, kukangana, kukanikiza, kupindika, ndi kupsinjika kwa torsion kumachita mokwanira pathupi la chitoliro, chomwe chimayika zofunika kwambiri pamtundu wa casing yokha. Boko lokhalo likawonongeka pazifukwa zina, chitsime chonsecho chikhoza kuchepetsedwa kuti chipangidwe kapena kuphwanyidwa.

Malinga ndi mphamvu ya chitsulo palokha, casing akhoza kugawidwa m'magulu osiyanasiyana zitsulo, monga J55, K55, N80, L80, C90, T95, P110, Q125, V150, etc. Zosiyana bwino zinthu ndi bwino kuya amafuna osiyana zitsulo kalasi. . M'malo owononga, chosungiracho chimafunikanso kuti chisawonongeke. M'malo omwe ali ndi zovuta za geological, casing imafunikanso kukhala ndi anti-collapse properties.