Imibhobho yeoli ekhethekileyo isetyenziswa ikakhulu ukugrumba ioli nerhasi kunye nokuthutha ioli negesi. Iquka umbhobho wokomba ioyile, isingxobo seoli, kunye nombhobho wokumpompa ioli. Umbhobho wokugaya i-oyile usetyenziswa ikakhulu ukudibanisa iikhola zokomba kunye namasuntswana okomba kunye nokuhambisa amandla okomba. I-oil casing isetyenziselwa ukuxhasa udonga lomthombo ngexesha lokugaya kwaye emva kokugqitywa kakuhle ukuqinisekisa inkqubo yokugaya kunye nokusebenza okuqhelekileyo kweoli yonke kakuhle emva kokugqitywa. Umbhobho wokupompa ikakhulu uhambisa ioli kunye negesi ukusuka ezantsi kweoli ukuya phezulu.

I-oil casing yindlela yokuphila yokugcina ukusebenza kwemithombo yeoli. Ngenxa yeemeko ezahlukeneyo zejoloji kunye neemeko ezintsonkothileyo zoxinzelelo, ukuxinana, ukucinezelwa, ukugoba, kunye noxinzelelo lwe-torsion lusebenza ngokubanzi kumzimba wombhobho, obeka iimfuno eziphezulu kumgangatho we-casing ngokwayo. Nje ukuba isingxobo ngokwaso sonakaliswe ngenxa yesizathu esithile, iqula lonke lingancitshiswa kwimveliso okanye lide lichithwe.

Ngokwamandla entsimbi ngokwayo, i-casing inokwahlulwa ibe ngamabakala ahlukeneyo entsimbi, angala J55, K55, N80, L80, C90, T95, P110, Q125, V150, njl. Iimeko ezahlukeneyo kakuhle kunye nobunzulu obunzulu bufuna amanqanaba ahlukeneyo entsimbi. . Kwiindawo ezonakalisayo, i-casing ngokwayo iyafuneka ukuba ibe nokumelana nokubola. Kwiindawo ezineemeko ezinzima ze-geological, i-casing nayo iyafuneka ukuba ibe neepropati zokuchasana nokudilika.