Process for reducing scale deposition in gas-lift wells

Claim 1

A PROCESS FOR INCREASING THE OIL PRODUCTION FROM A GAS-LIFT WELL PRODUCING FROM A LIMESTONE FORMATION WHICH COMPRISES THE STEPS OF REMOVEING A PREDOMINANTLY HYDROCARBON GAS AND OIL MIXTURE FROM THE WELL AND SEPARATING THEREFROM GAS CONTAINING MOISTURE, CARBON DIOXIDE AND HYDROGEN SULFIDE, THEREAFTER PASSING SAID GAS TO A ZONE WHEREIN SUBSTANTIALLY ALL HYDROGEN SULFIDE PRESENT IS REMOVED BY COUNTERCURRENT CONTACT WITH AQUEOUS METHYLDIETHANOLAMINE WITHOUT CONCOMITANT REMOVAL OF THE MAJOR PORTION OF THEREIN-CONTAINED CARBON DIOXIDE, PASSING SAID WELL GAS STRIPPED OF HYDROGEN SULFIDE TO A DEHYDRATION ZONE AND COUNTERCURRENTLY CONTACTING SAID WELL GAS WITH DIETHYLENE GLYCOL DEHYDRATION AGENT, AND RE-INJECTING SAID DEHYDRATED, HYDROGEN-SULFIDE-FREE, CARBON DIOXIDE-CONTAINING WELL GAS INTO SAID GAS-LIFT WELL AS GAS-LIFT GAS UNDER PRESSURE INTO CONTACT WITH OIL IN SAID WELL AND PRODUCING FURTHER QUANTITIES OF OIL FROM SAID WELL.