1. Used for associated gas recycle of offshore oil exploitation, differential structure, four-throws horizontal symmetrical balanced arrangement to ensure stability of compressor. 2.Adoption of seawater corrosion resistant material, long service life of compressor package; Perfect sealing effect and leakage rate is less than 3%. 3.Seawater cooling to decrease fresh water consumption, available for offshore platform and replaced imported ones. Small vibration, stable operation, reliable and long-service life to wearing parts. 4. Passed Classification Society Certification(CCSC) and confirmed to American Petroleum Standards of API618.