I-creefebied itanki yetanki ye-petroleum yerhasi
Ukuhlolwa kwamaxesha ngamaxesha ezitoriweyo zahlulahlulwe zangaphandle, ukuhlolwa kwangaphakathi nangaphandle kunye nokuhlolwa ngokubanzi. Umjikelo wokuhlola kufuneka umiselwe ngokufanelekileyo ngokusekwe kwimo yobugcisa kunye neemeko zokusetyenziswa kwezixhobo, kodwa uhlolo lwangaphandle kufuneka lube ngaphezulu konyaka, uhlolo lwangaphakathi nangaphandle okungenani kube kanye, kunye neminyaka emi-6. Ukuba itanki yogcino isetyenzisiwe iminyaka eli-15, uhlolo lwangaphakathi nolwangaphandle lufanele ukuqhutywa rhoqo kwiminyaka emibini; Ukuba itanki yogcino isetyenzisiwe iminyaka engama-20, uhlolo lwangaphakathi nangaphandle lufanele ukwenziwa ubuncinci kube kanye ngonyaka. Kwiitanki zokugcina eziye zahlolwa rhoqo, abasebenzi bohlolo baya kungenisa ingxelo yokuhlola ukubonisa ukuba itanki yogcino inokuqhubeka isetyenziswa okanye ukuba amanye amanyathelo kufuneka athathwe. Ingxelo yokuhlola kufuneka igcinwe kwifayile yobugcisa yetanki yogcino.