1. A system for de-bottlenecking an integrated oil and gas production plant including hydrogen sulfide removal and sour-gas injection, comprising:a water-selective membrane for receiving a teed stream comprising water-saturated sour gas containing 1-50% hydrogen sulfide by volume and forming a first retentate stream depleted in water and a first permeate stream enriched in water;
a hydrogen sulfide-selective membrane for receiving the first retentate stream to form a second retentate stream depleted in hydrogen sulfide and a second permeate stream enriched in hydrogen sulfide;
one or more gas processing plants for receiving the second retentate stream and further processing the second retentate stream to produce sales gases; and
a permeate compressor for compressing the second permeate stream and injecting the second permeate stream into an underground formation.