Borehole sucker-rod pumping plant for pumping out gas liquid mixtures

A borehole sucker-rod pumping plant for pumping out gas liquid mixtures, comprising:

• a driving rocker having an output member executing reciprocational movement in a vertical direction;
• a string of sucker rods having one end thereof connected to said output member and having a second end;
• a string suspension arranged in a well and in which said string of sucker rods is installed;
• a cylinder having an upper end connected to said string suspension, and a lower end;
• a plunger installed in said cylinder so as to be capable of reciprocational movement and connected to said lower end of said string of sucker rods;
• a pressure valve mounted in said plunger;
• a first suction valve mounted on said lower end of said cylinder and having an inlet side and an outlet side;
• a second suction valve arranged to be disposed in a wall of said cylinder at a level upstream and at a distance from said lower end of said cylinder and having an inlet side and an outlet side;
• a receiving chamber having an upper end and a lower end and arranged to be disposed coaxially upstream of said cylinder, said upper end of said receiving chamber being connected with said lower end of said cylinder and having an inlet for said gas liquid mixture at said lower end thereof;
• a central channel arranged in said chamber coaxially with said first suction valve, having a first end and a second end, said central channel the first end thereof in communication with said inlet side of said second suction valve, wherein the second end of said central channel is open into an interior space of said receiving chamber at a predetermined level;
• an inlet channel arranged in said receiving chamber and oriented substantially vertically, said inlet channel having a lower end and an upper end, said inlet channel having the lower end thereof in communication with said inlet of said chamber, wherein the upper end of said inlet channel is open into the interior space of said receiving chamber at a level located above said second end of the central channel so that, owing to this, there takes place the separation of said gas liquid mixture into a liquid phase which flows over from said upper end of said inlet channel into said second end of said central channel, and a gas phase which is accumulated in said upper end of the chamber;
• an outlet valve in the wall of said receiving chamber at said upper end thereof;
• and
• said outlet valve which has an actuation pressure thereof selected so as to ensure that said gas phase gets compressed in said upper end of said receiving chamber to take up a volume not exceeding the volume of that part of said cylinder which extends from said level where said second suction valve is disposed and up to said plunger when the latter is in its uppermost position.