Well sampling apparatus

Claim 1

APPARATUS FOR SAMPLING FLUIDS FROM A SUBSURFACE FORMATION PENETARED BY A WELL HAVING CASING SET THEREIN AND A TUBING STRING EXTENDING DOWNWARDLY THROUGH THE CASING FOR THE DELIVERY OF FLUIDS FROM THE WELL, COMPRISING A PUMP BARREL RETRIEVABLY MOUNTED IN THE TUBING STRING AT A LEVEL WHEREBY THE LOWER END OF THE PUMP BARREL IS IN WELL FLUIDS, SAID PUMP BARAREL HAVING AN OPENING AT ITS LOWER END AND A STATIONARY VALVE PERMITTING FLOW OF FLUIDS UPWARDLY INTO THE PUMP BARREL, AN OUTLET PORT IN THE UPPER END OF THE PUMP BARREL FOR FLOW OF WELL FLUIDS FROM THE PUMP BARREL INTO THE TUBING STRING, A TUBULAR PLUNGER FITTING SLIDABLY WITHIN THE PUMP BARREL, SAID PUMP BARREL HAVING AN EXTERNAL DIAMETER THROUGHTOUT ITS LENGTH LESS THAN THE INTERNAL DIAMETER OF THE TUBING WHEREBY THE PUMP BARREL MAY BE WITHDRAWN UPWARDLY THROUGH THE TUBING, AN INLET PORT IN THE LOWER END OF THE PLUNGER FOR THE ENTRANCE OF FLUIDS INTO THE PLUGER, A TRAVELING VALVE MOUNTED IN THE PLUGER ABOVE THE INLET PORT ADAPTED TO CLOSE THE INLET PORT WHEN PRESSURE WITHIN THE PLUNGER IS HIGHER THAN PRESSURE WITHIN THE PUMP BARREL, AN OUTLET PORT IN THE UPPER END OF THE PLUNGER, AN OUTLET VALVE POSITIONED IN THE PLUNGER BELOW THE OUTLET PORT ADAPTED TO CLOSE THE OUTLET PORT WHEN PRESSURE WITHIN THE PLUMGER IS HIGHER THAN PRESSURE WITHIN THE PUMP BARREL, AND OUTLET MOUNTED ON THE PLUGER ABOVE THE OUTLET VALVE, A CENTRAL OPENING EXTENDING DOWNWARDLY THROUGH THE GUIDE, SAID PUMP BARREL HAVING A CENTRAL HOLE IN ITS UPPER END, A SUCKER ROD ADAPTED TO BE CONNECTED TO DRIVING MEANS AT THE WELL HEAD EXTENDING DOWNWARDLY THROUGH THE CENTRAL HOLE IN THE PUMP BARREL AND THE CENTRAAL OPENING IN THE GUIDE, AN UPPER STOP ON THE SUCKER ROD ABOVE THE GUIDE TAO ENGAGE THE GUIDE AND LIMIT DOWNWARD MOVEMENT OF THE SUCKER ROD RELATIVE TO THE PLUNGER, SAID UPPER STOP BEING MOUNTED ON THE SUCKER ROD AT A POSITION WHEREBY ON DOWNWARD MOVEMENT OF THE PLUNGER THE LOWER END OF THE SUCKER ROD ENGAGES AND DEPRESSES THE OUTLET VALVE AND OPENS THE OUTLET PORT, AND A LOWER STOP MOUNTED ON THE SUCKER ROD WITHIN THE GIUDE ADAPTED TO ENGAGE THE GUIDE AND LIMIT UPWARD MOVEMENT OF THE SUCKER ROD RELATIVE TO THE PLUNGER, SAID LOWER STOP BEING MOUNTED ON THE SUCKER ROD AT A POSITION WHEREBY THE LOWER END OF THE SUCKER ROD IS OUT OF ENGAGEMENT WITH THE OUTLET VALVE DURING THE UPPER STROKE OF THE PLUNGER.