US2545175A - Control valve for deep wells - Google Patents

Description

Patented Mar. 13, 1951 UNITED STATES ssue NT o FICE CONTROL VALVE FORDEEP WELLS Orville R. Stump, Long Beach, and Arthur W. Titus, Whittier, Calif.

Application November 18, 1947, Serial No. 786,722

4'Claims. 1 Our invention relates to'means for closing at the bottom the tubing of a well for oil or other subterranean fiuid.

During such operations as withdrawing or running in the sucker rods or'the tubing, it is necestubing it adds materially to the labor to remove and insert a plug every time a stand of tubing is coupled or uncoupled. Furthermore, during the coupling or uncoupling of tubing the tubing string is unavoidably open for a short time.

In the past it has been a frequent practice to kill a well by pumping in mud or water before pulling the tubing, in order to avoid the d'ifficulties inherent in shutting ofi flow atthe well head. But it has been found that wells seldom if ever recover full productivity after such treatment.

An object of our invention is to'provide a valve capable of closing the lower end of a tubing string at times when such closure is desired, but capable of being maintained open durin productive operation of a well.

Further objects and advantages of our invention will appear from the following description and from the drawingjn which:

Fig. 1 is a sectional view illustrating our apparatus in place in a well; and

Fig. 2 is a view in elevation illustrating a device for maintaining the valve open during a wells period of free flow.

Referring to Fig. 1 of the drawing, I G represents a casing or liner, connected by collar H to slotted pipe l2 which is located in the productive portion of a well. Suspended within the casing is a tubingstringthe lowermost end of which is indicated at l3. A bottom lock shoe, consisting of the three elements I 4, l5, and l 6, is afiixed to the lower end'of thetubing.

Pump mandrel I? is the lower extension of the working barrel of a deep-well pump fitting Within the tubing. The mandrel is provided with a seating bevel i3 and with a hold-down consisting of dogs |9-i9 and springs ZED-28, adapted to engage the bottom lock shoe to inhibit vertical motion of the pump mandrel and members affixed thereto.

The foregoing elements are all conventional and may take any of the numerous forms customary in "wells having rod pumps with working barrels anchored to the tubing, including forms in which th holddown is situated near the top of the working barrel instead of in the bottom mandrel. Valve body Zi'is a cylindrical member threaded internally at each end and provided with internal shoulders facing eachend. The upper shoulder receives valve-seat ring 22 which is" held in place by collar 23. A centering guide consisting oftube 24 and a plurality of radial legs' 2525 is mounted within valve body 'Zl,the ends of the radial legs fitting against thelower shoulder of valve body '2! and being held in position by threaded nipple 26.

Valve stem '21, which is slidably fitted within tube 24, carries valve 23 at its uppe end. A helical spring 29 is mounted between valveiia and radial legs 25-25, to urge the valve upwardly into contact with valve-seat-ring 22'.

Co11ar23 is connected with the lower element [6 of the bottom lock shoe by nipple 3B, and

lower nipple 26 is connected at 3! with atail pipe, a gas anchor, or any other desired equipment.

7 At the lower end of pump mandrel'll is amxed a perforated mosquito-bill 3'2, of sufficient length to reach valve 28 and to hold the valve open when string and the attached pump are withdrawn from the well, valve 28 closes as soon as the pump is unseated. As a result, during the entire time that it is necessary or convenient to have the tubing string open at its upper end, flow of gas and oil through the tubing is inhibited by a bottom closure.

When the tubing itself is pulled or run into the well, the closure at the bottom of the string "makes unnecessary the troublesome and inadequate procedure of plugging the upper end of the tubing string each "time a stand of tubing is coupled or uncoupled.

It is entirely practical to insta l our bottomhole valve in a new well, when the tubing is first run into the well and before the drilling mud has been circulated out of the hole. However, in cases where the well is to have a period of free flow before going on the pump, it is necessary to provide a substitute for the pump anchor in the means for maintaining the valve open during productive operation of the well. A device for this purpose is illustrated in Fig. 2.

Anchor II! is, in its lower portion, the same in structure as pump mandrel I! of Fig. 1, and it is similarly equipped with elastically mounted hold-down dogs Il9--ll9 shaped and arranged to engage bottom-lock-shoe ring 15 of Fig. 1.

' The upper portion of anchor I I1 is provided with apertures l33l33, to permit flow of oil or other well fluid, and is surmounted by stub I34 which serves as a handle to be grasped by a fishing tool. Perforated mosquito-bill I32, identical or equivalent to element 32 of Fig. 1, is affixed to the lower end of anchor H7 and serves to maintain valve 28 open while the anchor engages the bottom lock shoe.

When the tubing is originally run into the well, it is provided with Whatever type of lock shoe or other anchor-engaging equipment that is required for the type of pump intended for eventual use in the well, and anchor II! is provided with a hold-down matching that of the pump or at least capable of engaging the same tubing equipment.

Anchor Ill remains in place throughout the period of free flow, unless it is desired to withdraw the tubing or to change its setting during this period. Valve 28 is not necessarily closed during the operation of changing the setting of the tubing, as this work may not involve opening the tubing head long enough to justify a bottom closure. But it should be noted that the valve may close automatically if an extreme gas pressure is encountered during the operation; thus the valve cooperates with the conventional blowout preventer at the well head to control the well in such an emergency.

When it is desired to pull the tubing or to run in a pump, the valve is closed by withdrawing anchor l H. Removal of the anchor involves the operation of running a fishing socket into the well without the benefit of a bottom closure, but this fact is of only minor importance. The fishing tool can be handled by a string of smoothjointed pipe or rod or, in some cases, by a cable; so it is not difficult to maintain an efficient closure of the tubing at the well head. If desired, anchor H! can be ailixed to a cable or rod string which is left in the well, in order to eliminate the fishing operation. i

We claim as our invention:

1. In a well provided with a tubing string, control means comprising: a valve body connected with the lower end of said tubing string and having a valve seat; a movable valve member mounted beneath said valve seat and arranged to close the passage into said tubing string by contact with said valve seat when at its upper limit of motion; resilient means urging said valve member upwardly toward said valve seat; an anchor fitting within said tubing and provided with hold-down means capable of engaging said tubing; and a member affixed to said anchor, arranged to bear upon said valve member and to hold said valve member away from said valve seat while said anchor is in engagement with said tubing.

2. In a well provided with a tubing string and with a pump having a working barrel fitting Within said tubing and anchored thereto, flow control means comprising: a valve body provided with a valve seat, said valve body being connected with the lower end of said tubing string beneath said pump; a movable valve member mounted beneath said valve seat and arranged to close the passage into said tubing string by contact with said valve seat when at its upper limit of motion; resilient means urging said valve member upwardly toward said valve seat; and a member aflixed to the working barrel of said pump, arranged to bear upon said valve member and to hold said valve member away from said valve seat while said working barrel is anchored to said tubing.

3. In a well provided with a tubing string and with a pump fitting Within said tubing, said pump having a part which remains stationary during normal operation of the pump, flow control means comprising: a valve body provided with a valve seat, said valve body being connected with the lower end of said tubing string beneath said pump; a movable valve member mounted beneath said valve seat and arranged to close the passage into said tubing string by contact with said valve seat when at its upper level of motion; resilient m-eans urging said valve member upwardly toward said valve seat; and a member affixed to said normally stationary part of said pump, arranged to bear upon said valve member and to hold said valve member away from said valve seat while said pump is in operativeposition.

4. In a well provided with a tubing string, control means comprising: a valve body connected with the lower end of said tubing string and having a valve seat; a movable valve member mounted beneath said valve seat and arranged to close the passage into said tubing string by contact with said valve seat when at its upper limit of motion; resilient means urging said valve member upwardly toward said valve seat; an anchor fitting within said tubing and provided with hold-down means capable of engaging said tubing, said hold-down means being adapted to release when the upward force applied to said anchor exceeds a predetermined limit; and a member afiixed to said anchor, arranged to bear upon said valve member and to hold said valve member away from said valve seat while said anchor is in engagement with said tubing.

ORVILLE: R. sTUMP. ARTHUR w. TITUS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,672,687 Penrod et a1 June 5, 1928 1,679,625 Penrod et al. Aug. 7, 1928 2,107,975 Beggs' Feb. 8, 1938

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