Isixhobo sokugrumba sisixhobo esidibeneyo esigrumba imithombo, efana nemithombo yeoyile okanye yegesi, phantsi komhlaba.
Iirigi zokubhola zinokuba zizakhiwo ezinkulu ezigcina izixhobo ezisetyenziselwa ukubhola imithombo yeoyile, okanye imithombo yokutsala igesi yendalo. Iirigi zokubhola zinokuthatha iisampulu zeeminerali ezingaphantsi komhlaba, zivavanye iipropati zomzimba zamatye, umhlaba kunye namanzi angaphantsi komhlaba, kwaye zingasetyenziselwa ukufaka izinto ezenziwe ngaphantsi komhlaba, njengezixhobo ezingaphantsi komhlaba, izixhobo, iitonela okanye imithombo. Iirigi zokubhola zinokuba zizixhobo ezihambayo ezifakwe kwiilori, kwiitrekhi okanye kwiitreyila, okanye izakhiwo ezihlala zihleli emhlabeni okanye ezisekelwe elwandle (ezifana namaqonga eoyile, adla ngokubizwa ngokuba 'zirigi zeoyile zaphesheya' nokuba azinawo umbhobho wokubhola).
Iirigi zokumba ezincinci ukuya kweziphakathi ziyashukuma, ezifana nezo zisetyenziswa ekubholeni izimbiwa, ekuqhumeni imingxunya, emigodini yamanzi nakwiphando lokusingqongileyo. Iirigi ezinkulu ziyakwazi ukubhomba kumawaka eemitha zomphezulu woMhlaba, zisebenzisa "iipompo zodaka" ezinkulu ukujikeleza udaka lokubhomba (i-slurry) nge-drill bit ukuya phezulu kwi-casing annulus, ukuze zipholise kwaye zisuse "iziqwenga" ngelixa kubholwa iqula.
Izikhonkwane ezikwirigi zinokuphakamisa amakhulu eetoni zemibhobho. Ezinye izixhobo zinokunyanzela i-asidi okanye isanti ukuba ingene kwiindawo zokugcina amanzi ukuze kube lula ukutsalwa kweoyile okanye igesi yendalo; kwaye kwiindawo ezikude kunokubakho indawo yokuhlala esisigxina kunye nokulungiselela abasebenzi (abanokuba ngaphezulu kwekhulu).
Iirigi zaselwandle zingasebenza amawaka eekhilomitha kude nesiseko sobonelelo ngokujikeleza okanye ukujikeleza kwabasebenzi rhoqo.
Singabonelela ngeerigi zokugrumba ukusuka kubunzulu obuziimitha ezingama-500-9000, zombini ziqhutywa yitafile ejikelezayo kunye nenkqubo yokuqhuba ephezulu, Kubandakanya i-rig efakwe kwi-skid, i-rig efakwe kwi-track, i-rig yokusebenzela kunye ne-rig engaphandle kolwandle.
