Downholde gas/oil separation systems for wells

Oil and gas are separated downhole in a free flowing well and are transmitted separately to the surface. Liquid oil is transmitted through an elongated tubing which extends into a liquid column in the bottom of the well and is anchored in a liquid production tubing string to form an annular flow space. Gas flows from a wellbore space above the column of liquid through the annular space and through a flow passage which may be formed by a side pocket mandrel into the well annulus and then to the surface. The liquid conducting tubing is secured in the tubing string and a seal point is formed by a packer above the gas flow passage formed by the side pocket mandrel. Alternative arrangements provide for a subsurface gas flow safety valve interposed in the gas flow path. The safety valve may be interposed in a cross-over body which permits flow of liquid and gas therethrough and past a seal formed between the body and the tubing string.