US2336977A - System for setting wells to control tubing pressure - Google Patents

Description

Dec. 14, 1943. R. N..BEAN El'AL 2,336,977

SYSTEM FOR SETTING WELLS TO CONTROL TUBING PRESSURE Original Filed May 9, 1939 4 Sheets-Sheet l Il'[: 1 115-2- T 15.15.

I 1NVENTOR5- R.N. B EAN 43g HERBERT A LLEN 9 [swank ATTORNEYS.

Dec. 14, 1943. R N BEAN T A 2,336,977

SYSTEM FOR SETTING WELLS TO CONTROL TUBING PRESSURE Original Filed May 9, 1959 4 Sheets-Sheet 2 I J 'E E I 143.5. I 'l:5 7

' [NVENTUR RILBEAN 5 BY WM ERBERT ALLEN 'afia'lh f3 Qluk, A TT0RN5Y6 Dec. 14, 1943. .R. N. BEAN ET AL SYSTEM FOR SETTING WELLS TO CONTROL TUBING PRESSURE 4 Sheets-Sheet 5 Original Filed May 9, 1939 VN A E b R ATTORNEYS Dec. 14, 1943. R. N. BEAN ET AL 2,336,977

SYSTEM'FOR SETTING WELLS TO CONTROL TUBING PRESSURE Original Filed May 9, 1939 4 Sheets-Sheet 4 IEE E filjj. III- INVENTORfi RNBEAN y HERBERTALLEN li ATTORNEYS,

drilling mud is present in the well when the drill- Fig. 1 is a side elevation of the release valve for UNITED STATES PATENT OFFICE SYSTEM FOR SETTING WELLS TO CONTROL TUBING PRESSURE Ruric N. Bean and Herbert Allen, Houston,.'1ex., assignors to Cameron Iron. Works, Houston, Tex.. a corporation Continuation of application Serial No. 272,577, May 9, 1939. This application October 14, 1940, Serial No. 361,128

Claims. (Cl. 16615) The invention relates to a system for setting a release valve for setting nipples used in comwells to control the tubing pressure so that the pleting wells. Well may be completed in order to produce after Another object of the invention is to provide the drilling has been finished without releasing an equalizer unit to be connected to a well head the pressure from the formation which is present 5. in order to remove a tubing back pressure valve in the well. without releasing the pressure in the well.

This application is a continuation application Other and further objects of the invention will for our prior application Serial No. 272,577 filed be readily apparent when the following descrip- May 9, 1939. tion is considered in connection with the accom- In the rotary method of drilling the heavy panying drawings wherein:

ing is finished. This heavy mud overcomes the the setting nipple used in practicing the invene pressure from the formation which is present tion.

in the well. It is necessary, however, to replace Fig. 2 is a side elevation with certain parts in this drilling mud with water or to otherwise wash l section illustrating the washing of the well and the mud out of the well and when this is done is a continuation of the lower end of Fig. 1.

the lighter liquid which replaces the mud is Fig. 3 is a vertical section of the tubing back usually insufficient to overcome the pressure in pressure valve which is removably carr ed y t the well so that as the drilling equipment is reupper end of the tubing.

moved from the well and the flowing equipment Fig. 4 is a side elevation showing the casing in added it is necessary to maintain a closure at the se ti n and illus r tin the P n of h Well upper end of the well or at the well head, bottom assembly when the well is being washed The usual practice is to run a strainer, packer as shown in Fig. 2. and string of tubing into the well so that the Fi 5 is a s d l vat n of t pressure equalstrainer will be located at the elevation of the izer unit used in removing the ub ng beck P producing formation and a packer is set about e V the upper end of the strainer in the well casing. 6 is a s de elev t on'pa y in section i to compel the flow to pass through the strainer lustrating the manner of removing the tubing and into a string of tubing. This equipment back pressure valve after the tubing has been must be lowered into the well bore and suitably landed and the prod cti n fittings attached t positioned while the pressure is on the well the e adbore. When it is understood that these pres- 7 ShOWS the Well bottom assembly With the sures are sometimes as great as five thousand Packer Set y the landing o thetllblng When the pounds per square inch it is apparent that every Parts are n th Pos t on of 6- precaution must be taken to manipulate the Fig. 8 s an e a d v w part y in secti n of parts while maintaining a seal to prevent this the p e equalizing unit of Fi pressure from escaping and mining the'well. Figs- 9 and a e Vertical Sect onal Views of It is particularly necessary that the pressure the Setting pp eas Va ve, i 9 Showi be controlled after the well has been washed .to the valve closed and Fig. 10 Showing the Valve remove the heavy drilling fluid and the present open- V invention concerns itself particularly with the In 2 the Well Surface casing is indicated type of equipment used at the well head in order generally t 2 d v s a a pport a d-holdto maintain the pressure in the well bore while down the W811 heed This d s 8- connecting and disconnecting the various fittrailed es'eall'yihg the Well easing 4 which tings, landed on a hanger 5 and clamped in place by An object of the invention is to provide a systhe hold-down mb y is a y is i tem for completing wells wherein the Washing turn held in p a e a blowout p e e t or of the well, the landing of t t b and t other form of closure 1 which has movable rams replacement of the drilling equipment is accom- 8 to 61056 t the String tubing 9 which is plished while maintaining a seal on the well. to be hung in the e Another object of the invention is to provide A ster v ve I0 is mounted on the blowout various pieces of detailed equipment which are preventer and this i in turn s u t d by a particularly useful in completing a well under s ond b ou p eve t pressure, The equipment just described is that which Another-object of the invention is to provide m y have been positioned on the well during the drilling operation or there may have been other and heavier equipment on the well. As seen in Fig. 2, the drilling operation has just been completed, and the well bottom assembly and the tubing string have just been run into the well which still contains the drilling mud.

The well bottom assembly is best seen in Fig. 4, wherein the well casing 4.is illustrated as having been perforated'at l3 to permit the entry of fluid from the formation. The well bottom assembly includes the strainer II, the inlet control valve IS, the packer l9, and the sealing valve II. The wash pipe or tubing 9 supports these parts as they are being lowered into the well bore and the valve I l which is arranged to seat at I9 is open so that the well may be washed and mud *irculated from the bottom of the well bore. The particular construction of this well bottom assembly is disclosed in the copending application of Herbert Allen Serial No. 291,189 filed August 21. 1939, for a Tubing valve and a continuation thereof Ser. No. 499.393 filed August 20, 1943 for Circulating type packer and valve therefor.

When the well bottom assembly and tubing is lowered into the well bore the coupling |9 at the upper end of the tubing will be equipped with a back pressure valve indicated generally at 29 in Fig. 2 and shown in detail in Fig. 3. This back pressure valve includes a housing 2| and a valve member 22, which includes the stem 23. A spring 24 seated in a recess in the housing bears against a flange 25 on the valve stem to normally hold the valve member raised and in en agement with the valve seat 29. This closes off the passages 21 through the valve. The valve opens downwardly and will be normally closed except when it is forced open by pressure from above. In this manner upward flow through the tubing 9 is normally cut oil.

Above the valve 29 a setting nipple 29 is connected to coupling l9 in order to manipulate the string of tubing 9. The upper end of this setting nipple 29 is best seen in Fig. 1 and carries a valve housing 48 which incorporates a particular valve 39 shown in Figs. 9 and 10, and which will be later described. Above the valve 39 the setting nipple is provided with an internal strainer 3| which keeps .any extraneous matter from entering into the tubing and wash line during the washing operation. The upper end of this nipple will be connected to a suitable swivel or other device so that liquid under pressure may be pumped into the well to displace the heavy drilling mud which is in the Well when the drillin operation is finished.

native the blowout preventer I instead of the pre- It should be borne in mind that during this entire manipulation the heavy drilling mud has prevented the formation pressure from blowing out and that now during the washing operation when the heavy drilling mud is displaced by water or other lighter liquid, the well approaches its most dangerous condition and the greatest precaution must be taken. The outlets 33 and 34 will be suitably controlled by valves so that they may be closed at any time, and, of course, the seal of the blowout preventer |2 about the setting nipple 29 completely closes off the well. The flow line connections 32 of the well head 3 will .of course be closed.

When the washing operation is completed it is now necessary to land the tubing in suitable position, it being understood that during the washing operation the tubing was raised from the position in which it would eventually land and in some instances it is raised and lowered during the washing operation to agitate the well and may be rotated because of the non-rigid support or connection with the blowout preventer which is both closing about the pipe and acting as a support.

The setting nipple 29 is now lowered somewhat so that when the strainer |4 rests on the well bottom as seen in Fig. 7, the tubing 9 will telescope downwardly inside of the packing l6 moving the valve so that it contacts the seat at Ill. The weight of the string of tubing thus serves to expand the packers |6, as seen in Fig. 7, to form a seal with the casing. The rams 8 of the blowout preventer 1 are now moved inwardly so as to receive the shoulder 36 of the upper end l9 of the tubing so that the desired proportion of the weight of the string of tubing will be carried by the rams and the entire weight will not be supported on the bottom of the well.

The tubing is now properly landed and is supported on the rams 8, as seen in Fig. 6. The washing liquid has been forced through the setting nipple 29, the valve 39 and the valve 29 under pressure, and after the tubing is landed this fluid pressure is still present in these parts and it is necessary to release the pressure in the setting nipple 29 before it can be unscrewed from the upper end IQ of the string of tubing. To accomplish this end the valve 39 is manipulated to release this pressure.

It is desirable to support only a certain portion I of the weight of the tubing on the bottom of the well and to support the remainder in a suitable hanger such as the blowout preventer 1. To accomplish this the setting nipple 29 is manipulated until the strainer |4 rests on the bottom of the well, as seen in Fig. 4, and then the tubing is raised the desired amount and the section or coupling 9 inserted, which is of a suitable length so as to provide a shoulder 36 on the tubing whichcan be supported upon the rams 8 of the blowout preventer I as seen in Fig. 6. i

In order to wash the well the upper blowout preventer I2 is closed about the setting nipple to form a seal and the washing liquid is then returned upwardly and ,may discharge from the outlet 33 in the blowout preventer I or some may discharge from the flow connections 34 above the master valve l9, or as another alter- The valve 39 is best seen in Figs. 9 and 10 and includes a valve member 49, which is carried on a stem 4| slidably mounted in the body 42. The valve member engages a seat 43 so as to close the ports 44, while the coil spring 45 normally urges the valve to seating position. The pressure on the spring 45 may be adjusted by turning a sleeve 46 to adjust the compression on the spring.

During these operations the valve 39 will generally be exposed above the top of the uppermost fitting |2 on the well and the valve 39 is so arranged that it may be opened or closed from the outside of the nipple. To accomplish this a shaft 41 is rotatably mounted in the walls of the coupling 48 and suitable packing 49 prevents leaking around this shaft. A non-circular opening 59 will admit a suitable tool so that this shaft 41 may be rotated. The stem 4| is connected to an eccentric portion 5| of the shaft 41 so that as this shaft is turned the valve will be forced downwardly as seen in Fig. 10. In this manner any pressure present in the setting nipple below the valve 39 may be released by turning of the the tubing. The back pressure valve 26 con- 5 nected into coupling I9 prevents the escapeof pressure through the inside of the tubing and the fact that'the blowout preventer rams 8 are closed about the portion I9, as seen in Fig. 6, prevents any escape whatever of pressure from the well. 1

The setting nipple 29 can be removed and any fittings above the blowout preventer 'I can also be removed because the well is completely closed by the rams 8 and the valve 20. The usual practice is to remove the larger fittings such as a large valve I0 and the blowout preventer I2 and to replace these with smaller valves which will merely permit the passage of the tubing 9, whereas the larger valves present during the drilling operation would permit the passage of the drill stem and drill bit.

When the suitable flttings for the production of oil have been added it is then desirable to open up the tubing so as to permit a flow of oil or gas from the well. To accomplish this a pressure equalizer unit is connected to the upper end of the master valve 62 of the well casing apparatus. This unit is shown in elevation in Fig. 5 and the detailed construction thereof in Fig. 8.

This equalizer unit includes a tubular element 60 having a lower externally threaded area 60a, connected into a flange BI and an upper threaded area 66b connected into a hollow lower union 63a and communicating therewith. Flange 6| is mounted upon the upper flange of a gate valve or master valve 62 which may be the same as the valve I6 but is preferably a valve of somewhat smaller size. In any event this equalizing unit is made up of a body 63, which comprises a solid arm 64 and a hollow arm 65 which are in the form of a yoke with their.v adjacent lower ends threaded into said hollow lower. union, into which is also threaded the lower stuffing box 66 through which a rod or stem 61 is arranged for sliding movement. The passage in hollow arm 65 communicates with the hollow lower union.

The upper portions of the arms are connected into a hollow upper union 63b, which also carries a stufiing box 68 aligned with stufllng box 66 and slidably sealing about the rod 61 at its upper end. A valve 69 in hollo'w arm 65 may be closed to cut oil the flow of fluid through this hollow arm. The upper end of the stem 61 runs into a chamber I6 which may be of any desired length and communicates with hollow arm 65 through the upper union. A needle valve 7| is connected into the arm 64 and a. fluid passage in the arm leads from valve II into the chamber 10 so that fluid pressure may be released from this chamber.

The lower end of the stem 61 is externally threaded and the stem passes downwardly through the tubular element 60 and engages 7 within the threads I3 inside the housing 2| of the tubing back pressure valve 20, Fig. 8 show- 5 ing the valve 20 as connected to the lower end of the stem. The lower threaded end of the stem 61 is of sulficient length so that when it is turned relativeto the threads I3 in one direction it will engage the stem 23 of the valve member 22 and cause the valve to move to open position if the stem is threaded into the valve body M a sufli-' cient distance. This equalizer unit when connected to the flange BI is arranged to remove the tubing back pressure valve 20. When the valve 20 is opened as has just been described the fluid pressure will flow upwardly along the stem 61 and into the arm 65. In order to prevent excessive pressure on the stem 61, however, the

valve 69 will be opened so that this pressure is available in the chamber I0 and therefore the pressure on the cross sectional area of the stem 61 will be equalized and there will be no tendency for the well pressure to blow the stem 61 upwardly. The stem 61 can be manipulated by connecting a suitable wrench to it between the stufling boxes 66 and 68.

With the parts in the position just described the well pressure is now available in the arm 65 and the chamber 10 and back pressure valve 20 can be readily unscrewed from coupling I9 by turning the stem 61. When the back pressure valve has been unscrewed from coupling I9 it is then desirable to raise it a sufficient distance so that the master valve 62 may be closed to completely cut off the well. To accomplish this the valve 69 is now closed and the needle valve II is gradually opened to release the fluid pressure from the chamber I0. This release causes a reduction in pressure on the upper end of the stem 61 so that the well pressure will automatically move the stem upwardly or it may be raised manually to raise the valve 20 above the gate member in the master valve 62. The master valve can'now be closed and the well is completely cut oil with the well pressure available in the head.

- bull plug or flow line can then be used to close the upper end of the valve 62 in Fig. 6. The well has now been completely washed, the tubing landed and is ready to be turned into production.

If the production of the well is to pass through the flow lines above the master valve it is only necessary now to open the master valve and open the flow line valves which will be connected on the outlets 34 and the Well is ready to produce under its own pressure. The procedure just described may be reversed if the tubing is to be removed or the well reworked.

What is claimed is:

1. In an assembly of equipment for completing wells under pressure, a string of tubing, a tubing back pressure valve at the upper end thereof to prevent upward flow therethrough, a setting nipple connected above said valve to said tubing so that liquid under pressure may be pumped into said tubing, and a release valve sure in the nipple and operable whereby the pressure residing within the nipple after the washing operation may be released without releasing the well presure in the tubing below said back pressure valve.

2'. A pressure equalizer unit for completing wells under pressure including a body made up of spaced arms, a packing gland at each end of the body, a stem slidable in said glands, an enclosure for one end of the stem, a passage from one end of said body around said glands to said enclosure, a valve in the pasage for controlling flow therethrough' and a release valve operable to release the fluid under pressure from the enclosure.

3. A' pressure equalizer unit for completing wells under pressure including a body made up,

of spaced arms, a packing gland at each end of the body, a stem slidable through said glands, an enclosure for one end of the stem, a passage through said body and one of the arms, a valve in the passage in said one of the arms for controlling flow therethrough, a release valve to release the fluid under pressure from the enclosure, said body being arranged to be connected to a well tubing to communicate said passage in said body with said tubing. and means on said stem to engage a valve member positioned in said tubing.

4. A pressure equalizer unit for completing wells-under pressure including a body made up of spaced arms, a packing gland at each end of the body, a stem slidable in said glands and exposed between the glands to be engaged for movement thereof, an enclosure for one end of the stem, and means connecting and providing a passage from one end of said body past said packing means to said enclosure at the other end, and a release valve operable to release the fluid under pressure from the enclosure.

RURIC N. BEAN. HERBERT ALLEN.

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