Disclosed are systems and methods for producing oil and gas in a plant while removing hydrogen sulfide and water from fluids produced from oil and gas reservoirs and injecting a sour gas stream containing the hydrogen sulfide into an underground formation. Water-selective membranes are used to debottleneck known systems and methods by removing water from bottlenecked sections of the plant including pretreatment of a sour gas feed to one or more gas processing plants. In other aspects, water-selective membranes are used to debottleneck the pretreatment of an acid gas feed to a Claus unit to convert hydrogen sulfide to sulfur in a gas processing plant. The water-selective membranes pretreat the acid gas feed.