A gas separator connectable between the seating nipple/pump and the mud anchor of a well production line takes advantage of gravitational, shear and centrifugal forces to detrain gas from the formation fluid. An outer cylindrical tube is concentrically secured by upper and lower couplings in relation to an inner cylindrical tube having an axial flow passage and a plurality of radial perforations. The upper coupling is adapted for connection to the seating nipple/pump and the lower coupling is adapted for connection to the mud anchor. The couplings each have a passage therethrough to extend the inner tube axial flow passage in fluid communication between the pump and the mud anchor. The outer cylindrical tube has a plurality of inwardly downwardly centrifugally oriented passages for admitting liquid entrained with gas into an annulus between the tubes and for causing the admitted liquid to flow in a downward spiral in the annulus. The centrifugally oriented passages have irregular sawtooth surfaces extending inwardly downwardly and approximately tangentially in relation to the inner wall of the outer cylindrical tube so as to shear the gas from the fluid and centrifugally cause the gas to move inwardly and the oil and gas combinations to move outwardly in the annulus.