Foot valve for pumping wells

Claim 1

Apparatus for plugging a well conduit below a rod-type well pump upon withdrawal thereof from the well, said apparatus including: (a) foot valve nipple means having a bore extending therethrough and having attachment means at its upper end for attachment to a well conduit, said foot valve nipple means further including: (i) lateral port means, (ii) an annular seat surface in said foot valve nipple surrounding said bore above said lateral port means, and (iii) support means below said lateral port means and a spaced distance below said annular seat surface providing an upwardly facing stop shoulder; (b) foot valve means in said foot valve nipple means and supportable in its lower, open position by said upwardly facing stop shoulder and movable to an upper, closed position of engagement with said annular seat means to plug the same, said foot valve means including: (i) foot valve body means formed with downwardly facing shoulder means engageable with said upwardly facing stop shoulder means in said housing, and a seat surface spaced above said downwardly facing shoulder, and (ii) a fishing neck stem on said foot valve body projecting upwardly therefrom and being engageable by means for lifting the foot valve to a position of engagement with said annular seat surface of said foot valve nipple means; and (c) foot valve operator means attachable to the lower end of a well pump for lifting and lowering said foot valve means between its open and closed positions in said foot valve nipple means, said foot valve operator means including: (i) housing means having means at its upper end for attachment to the lower end of a well pump, an upwardly opening bore with lateral inlet means for communicating said upwardly opening bore with the exterior of said housing means, and a downwardly opening bore having an internal annular recess in its wall, an internal annular flange spaced below said recess, and limit means thereabove, and (ii) releasable latch means carried in said downwardly opening bore and movable between engaging and releasing positions, said latch means having detent means thereon engageable in said internal recess of said downwardly opening bore of said housing means to releasably hold said latch means in its engaging position and being releasable in response to a predetermined tensile load, said latch means having latch members at its lower end for engaging and latching onto the upper end of said fishing neck of said foot valve means, said latch members being held in engaging position by said internal flange of said downwardly opening bore when said latch means is supported in its detented position, and downwardly facing shoulder means on said latch means engageable with said internal flange in said housing means to limit movement of said latch means to its release position, in which position the latch members open to disengage from said fishing neck on said foot valve.

Claim 7

The device of claims 1, 2, 3, 4, or 5, wherein said foot valve nipple has a portion thereof internally threaded a spaced distance below said internal annular seat, and said upwardly facing stop shoulder is provided by a stop ring threadedly engaged in said internally threaded portion to permit fine adjustment of its position in said tubular housing.

Claim 9

The method of operating a pumping well, comprising the steps of: (a) providing a plugging device including a foot valve nipple having an annular seat surface therein and a foot valve for plugging said nipple, and placing said foot valve in said foot valve nipple below said annular seat and attaching said foot valve nipple to the well tubing, and attaching a pump seating nipple in said well tubing a spaced distance above said foot valve nipple; (b) assembling and installing the well tubing in the well with the pump seating nipple located at the desired level therein; (c) providing a well pump and operator means for latching onto a fishing neck of said foot valve, and attaching said operator means to the lower end of said well pump; (d) lowering said well pump into the well on a sucker rod string and carefully seating it in said pump seating nipple so that, said operator means becomes engaged with said foot valve therebelow; (e) manipulating said sucker rod string to actuate said well pump to pump fluids from the well; (f) ceasing actuation of the well pump, and lifting the well pump and said foot valve until the foot valve engages the annular seat surface in the foot valve nipple to plug the foot valve nipple; and (g) bleeding pressure from the tubing above the plug, disconnecting said pump from said foot valve, and withdrawing the sucker rods and well pump from the well.

Claim 10

The method of operating a pumping well, comprising the steps of: (a) providing a plugging device including a foot valve nipple having an annular seat surface therein and a foot valve for plugging said nipple, and placing said foot valve in said foot valve nipple below said annular seat and attaching said foot valve nipple to the well tubing, and attaching a pump seating nipple in said well tubing a spaced distance above said foot valve nipple; (b) assembling and installing the well tubing in the well with the pump seating nipple located at the desired level therein; (c) providing a well pump and operator means for latching onto a fishing neck of said foot valve, and attaching said operator means to the lower end of said well pump; (d) lowering said well pump into the well on a sucker rod string and carefully seating it in said pump seating nipple so that, said operator means becomes engaged with said foot valve therebelow; (e) manipulating said sucker rod string to actuate said well pump to pump fluids from the well; (f) ceasing actuation of the well pump, and lifting the well pump and said foot valve until the foot valve engages the annular seat surface in the foot valve nipple to plug the foot valve nipple; and (g) bleeding pressure from the tubing above the plug, disconnecting said pump from said foot valve, and withdrawing the sucker rods and well pump from the well.