US2368428A - Multiple zone production apparatus - Google Patents

Description

D. F. SAURENMAN MULTIPLE ZONE PRODUCTION A `Fan. 30, 1945.

PRARATUS Filed' June 30 1941 2 Sheets-Sheet l INVENTOR .Ance/Vey.

D. F. SAURENMAN4 MULTIPLE ZONE PRODUCTION APPARATUS Jan. 30, 1945.

Filed June 30, 1941 Z'Sheets-Sheet 2 INVENTOR Patented im.' ao, 194s #UNITED STATES PATENT VoFFici?. f

' I z,sss,42s l 'MULTIPLE zoNE PRODUCTION APPARATUS Dean F. Saurenman, Houston, Tex., assigner to Baker Oil Tools, Inc., Vernon, ACalif., a corporation of California Appunti@ June so, 1941, serial No. 400,404

(ci. l16s-1) 6 Claims.

This invention relates to production control apparatus particularly useful in connection with the multiple zone production of oil and gas wells. AIn oil and gas wells having a plurality of producing zones, it is desirable to maintain the production from each zone separate. In some instances, the various zones may be' owed individually to the surface of the well bore, but if the formation pressure of an upper zone is too lowl it is essential that its production be pumpedsurface of the can be produced separately or simultaneously, as

desired.

A further object of the invention is to provide an apparatus in which an upper or lower producing zone may be produced separately or simultaneously through a single tubular string.

In situations wherein an upper zone is being pumped through production tubing, while production from the lowerzone ows to the surface of the well bore through the annular space between the tubing and casing, depletion of the formation pressure in the lower zone will prevent its continued flowing, leaving a substantial head of oil in the aforementioned annular space. It is a further object of the present invention to provide an apparatus which will not only allow an upper producing zone to be pumped through tubing and a lower producing zone to flow inde- 'pendently of the upper production to the surface of the bore, but which can also eilect the pumping of the uid from the annular` space between the tubing and casing whenever desired.

Yet another object of the invention is to provide an apparatus in which the production from spaced zones in a well bore can be pumped simultaneously through separate channels to the surface of the well bore. y

This invention has other objects that will become apparent'from a consideration of the embodiments shown in the drawings accompanying and forming part of the present specication. These forms will now be described in detail to illustrate the general principles ofthe invention, but it is to be understood that such detailed description is not to be taken in a limited sense, since the scope of the invention is best defined by the claims appended hereto.

Referring to the drawings:

Figures 1, 2, 3 and 4 are longitudinal sections through a multiple zone well bore illustrating the production apparatus of the present invention in different positions of operation;

Figure 5 is a longitudinal section' through a well bore showing a modified form of apparatus;

' Figure 6 is a longitudinal section on an enlarged lscale of part of the iiow apparatus disclosed in Figures 1 to 4, inclusive; and

Figure 'l is a cross-sectionV taken along the I-l in Figure 6. A

As disclosed in the drawings, a casing or liner string A is run in the well bore with an upper set of perforations B positioned opposite an upper producing zone, and a lower set of perforations C positioned opposite a lower producing zone. A lower production packer I0 is anchored in packedline on condition in the casing between the upper and lower casing perforations to isolate the production from the two zones. Similarly, an upper production packer II is anchored in the casing in packed-od' condition above the upper perforations.

The production packers III, II may be` of any suitable type. Those illustrated are specifically described in United States'Patent No. 2,189,703, being designed for anchoring in the casing against movement in both longitudinal directions. Each of these packers consists of a generally tubular body I2 carrying a set of upper slips I3, which are cooperable with an upper expander cone Il mounted on the body to secure the latter against movement in an upward direction with respect to the casing A. A lower set' of slips I5 is also provided for cooperation with alower expander cone I8 mounted on the body to secure the latter against movement in the casing in a downward direction. A packing sleeve I 1 between the two expander cones effects an annular seal between the body I2 and casing A, for the purpose of preventing passage of fluids therebetween.

Each packer is designed to permit movement of production tubing D through its body I2 without'leakage between the exterior of the tubing and the body. To this end, upper andlower packing seals` I8, I9 are secured in the body for slidable engagement with the production tubing signed, for one position of operation, as to allowy production from the upper producing zone to be either ilowed or pumped through the tubing D. while production from the lower producing zone is directed in a separate path through both packers I0, Il for passage through the annulus 26 between the tubing D and casing A above the upper packer II. To permit this mode of operation to occur, a portion of the production tubing has a by-pass includinga-T 2| secured therein in any suitable manner, as by fillets 22 of welding material integrating the outer ends of the T to the walls of an upper sub 23 threaded on an upper joint on tubing 24 (see Figures 6 and 7).

An outer tube 25* depends from the upper sub 23, having a lower sub 26 screwed on its bottom terminus, from which extends a lower production string 21 terminating in a buil nose 28 for guiding the tubing into the packers. An inner by-pass tube 29 is disposed within the outer tube 25, with its upper end screwed into the by-pass T 2|, isolation of fluid within the by-pass 2|, 29 from that around the by-pass and within the outer tube 25 being eiected by extending the by-pass tube 29 through an inwardly extending section 30 of the lower sub 26 and providing a packing seal 3| between this section and tube 29. The seal 3| is compressed by a packing nut 32 threaded into the sub 26 to prevent passage of uids between the outer tube 25 and the inner tube 29.

Due to the by-pass arrangement disclosed, iiuid can flow through the inlet ports 33 at the lower end of the lower production tubing 21 for upward passage through this tubing and into the uid inlet at the bottom end of the by-pass inner tube 29, continuing through this inner tube for exhaustion through the iluid outlets 34 in the by-pass T 2| connection and upper sub 23. Fluid may also enter the annular space 35 between the outer tube 25 and the exterior of the inner tube 29 through the uid inlet ports 36 in the lower sub 26 for upward passage around the by-pass T 2| into the upper production tubing 24, from where it can iiow or be pumped to the surface of the well bore.

It is to be noted that the lower tubing 21. upper tubing 24, intermediate outer tube 25, and connecting subs 23, 26 are all externally ush to allow a slidable sealing movement of the tubing string D through the packing seals I8, I9 xed at the upper and lower ends of the production packers I0, II. It is only essential for the tubing to be externally flush along the length movable through these packers. Any other suitable type of tubing or tubing connections may be employed above this particular section.

Many production control positions are possible with the production tubing and` production packer arrangement disclosed in the drawings. The different positions may be selected merely by elevating or lowering the tubing within the casing. the slidable sealsr I8, I9 functioning to prevent passage of uids along the exterior of the tubing through the production packers in, I I

As disclosed in Figure 1, the outlets 34 of the by-pass 'r 2| are positioned above the upper production packer II. the iluld inlets 36 formed through the lower sub 26 are positioned between the production packers, and the inlet openings 33 in the lower tubing are positioned below the lower production packer I0. With the parts located in this manner, fluid from the lower zone can flow through the lower tubing 21, inner bypass tube 29, T connection 2|, into the annulus 2D between upper production tubing 24 and casing A, while production from the upper zone can flow through the inlet ports 36 in the sub 26 and through the annulus 35 around the inner tube 29 and around the T 2| into the upper production tubing 24, through which it can either iiow or be pumped to the surface of the well bore, independently of the production from the lower zone.

As illustrated in Figure 2, the producing string has been lowered so as to position the by-pass T 2| between the upper and lower seais I8, I9 in the upper production packer II. When in this position, production from the lower zone is shut in or stopped, since the upper and lower seals prevent flow around the tubing string 24 or 25 through the packer body I2; but the upper zone can either flow or be pumped through the tubing in the same manner as described in connection with the Figure l position, in view of the location of the inlets 36 between the packers I0, i I.

If the tubing string is elevated so that the fluid inlets 36 in the lower sub 26 are positioned between the upper and lower seals I 9, I9 of the upper production packer II, the upper zone is shut in and production can be obtained only from the Vlower zone, iiowing through the lower tubing 2l and by- pass 29, 2| into the annular space 2li between the production tubing and casing above the upper packer II (see Figure 3).

Whenever the head of fluid in the annulus 20 between the production tubing D and casingl A above the upper packer II is greater than the formation pressure in the lower zone, the latter zone will cease to ow. Should this condition obtain, the elevation oi' the producing string to the position illustrated in Figure 4 enables this annulus to be relieved of its iiuid head. This is accomplished by locating the lower tubing inlet openings 33 between the upper and lower seals I8, I9 in the lower packer l0 and the fluid inlet ports 36 normally employed for the upper producing zone above the upper packer il. To prevent production from ilowing into the lower tubing 27 when in this position, a back-pressure valve 3I in the form of a apper 38 closed by a spring 39 is pivotally mounted at the bottom end of the lower packer i0, automatically engaging its cooperable valve seat 40 in the bottom of the packer. Moreover, production from the upper zone is also arrested, due to the sealing action of the seals I8, I9 of the upper packer against the external surface of the tubing D, and the location of the inlet ports 36 above the upper packer Il. The annulus 20 between the producing tubing D and casing A, however, is now in communication with the interior of the production tubing string D through these inlet ports 36, which enables'the uid in this annulus 29 to be unloaded or pumped through the production tubing whenever necessary.

Should it be desirable to shut in the upper zone and pump the lower zone through the tubing. the tubing string D is lowered until the nuid inlet ports 38 in the sub 26 are positioned below the lower seal I9 in the lower packer I0, the uid outlets 34 oi the by-pass T preferably point through the tubing to the surfacey cf the well bore. Ii' the upper and lower packers i0, Il are spaced apart sumciently, it might be possible to'- produce both zones simultaneously through the tubing by lowering the tubing D until both the by-pass r 2| and the lower sub ports I9 are positioned between the packers I0, Il. 'I'he production from the upper zone then flows into the tubing through the iluid inlet ports 99 as before, and in addition, production from the lower zone flows through the lower tubing 21 and inner by-pass tube 29 for exitithrough the by-pass T 2| into the annular space between. the packers, joining the production from the upper zone for passage through'the inlet ports 36 into the production tubing and to the well surface.

, ascuas Beals Various other operating conditions can Coei had by suitable maniplation of the tubing D with respeot to the packers I0, I-l, so as to obtain simultaneous or separate flowing of the production from each zone either through the tubing or through the annular space 20 between the tubing and casing. 'Ihe apparatus may also 'be used to -repressure one zone from the other by proper positioning of the tubing with respect to the packers.

A modified form of apparatus is illustrated in Figui-e 5. Instead of a single length of tubing 24,

two separate sets 4I, 42 extend from the flush joint tubing apparatus upwardly to the surface of the well bore. One string of tubing 42 is connected to the outer tube 25, while the inner by pass tube 29 is connected to the otherstring of tubing 4|. With this particular device, it is possible toflow or pump the upper and lower zones separately through individual tubing strings. For example, production from the lower zone can packer. respectively, for by-passing fluid from said lower zonethrough said upper zone to a point above said upper packer, said production string also having an inlet adapted to be positioned between said packers for delivering fluid from said upper zone into the production string and for conducting it through said string to the surface of the/well bore independently of the production flowing through said by-pass means, said production string being movable as a unit to shift the positions of said inlets and outlet with respect to said packers. v

2. Well production apparatus, including a `packer for separating the production from upper and lower zones in a well bore, a second packer above said upper zone, and a -production string having externally flush joint tubing adapted to extend through both of said packers in leak-.proof relation with respect thereto, said flush ljoint tubing having by-pass means provided with an inlet and outlet adapted to be positioned below said lower packer and above said upper packer, respectively, for by-passing iluid from said lower zone through said upper zone to a point above said upper packer, said flush joint tubing also having an inlet adapted to be ypositioned between said packers for delivering fluid lfrom said upper zone into the production string and for conducting it through said string to the surface of the well bore independently of the production flowing through said by-pass means, said production string being movable as a unit to shift the positions 0f said inlets and outlet with respect to said ing means between said production string and pass into the lower tubing 21 and through the inner by-pass tube 29 into one of the tubing strings 4|. On the other hand, production from the upper zone passes through the iuid inlets 36 in the lower sub 2B into the annulus 35 ,between4 the inner and outer tubes iior upward flowing or pumping through .the other string of tubing 42. By use of this device, each zone may either be flowed or pumped, avoiding the necessity for shifting the tubing in the casnig in the event that the formation. pressure of the lower zone drops suiciently so as to be unable to overcome the hydrostatic head of fluid thereabove, as described in connection with the Figure 4 position.

It is apparent that a nove] multiple zone production apparatus has been provided which is lcapable of allowing the upper zone to be pumped through a tubular string, while obtaining separate ow from a lower producing zone. Merely through the expedient of raising or lowering the production string, it is possible to produce selectively from either or both zones in various ways.

Iclaim:

1. Well production apparatus, including a packer for separating the production from upper and lower zones in a well bore, a second packer above 4said upper zone, and a production string adapted to extend through both of said packers in leak-proof relation with respect thereto, said production string having by-pass means provided with an inlet and outlet adapted to be positioned below said lower packer and above said upper packers to prevent leakage therebetween, said production string having .by-pass means provided with an inlet and an outlet adapted to be positioned below said lower packer and above said upper packer, respectively, for by-passing uid from said lower zone through said upper zone to a point above said upper packer, said production string also having an inlet adapted to fbe I positioned between said packers for delivering fluid from said upper zone into the production string and for conducting it through said string to the surface of the well -bore independently of the production flowing through said l y-pass means, saidA production string being movable longitudinally as a unit to shift the positions of said inlets and outlet with respect to said packers.`

4. Well production apparatus, including a packer for separating the production from upper and lower zones in a well bore, a second packer above said upper zone, and a production string adapted to extend through lboth of said packers in leak-proof relation with respect thereto, said production string having .by-pass means provided with an inlet and outlet adapted to be positioned below said lower packer and above said upper livering fluidfrom said upper zone into the production string and for conducting it through said string the surface of the kwell bore independently .of the production nowing through said bypass means and around said production string, said production vstring being movable as a unit to shift the positions of said inlets and said outlet with respect to said packers.

5. Well production apparatus, including a packer for separating the production from upper and lower zones in a well bore, a second packer above said upper zone, and a production string adapted to extend through both of said packers in leak-proof relation with respect thereto, said production string having by-pass means provided with an inlet and outlet adapted to be positioned below said lower packer and ainove said upper packer, respectively, for by-passing fluid fromA said lower zone through said upper zone to a point above said upper packer where said fluid will pass outwardly of the production string for upward lflow therearound to the surface of the well bore, said production string also having an inlet adapted to be positioned between said packers for delivering fluid from said upper zone into the production string and for conducting it throughsaid string around said by-pass means to the surface of the well bore independently of the -production flowing through said ilay-pass means, said production string being movable as a unit to shift the positions of said inlets and outiet with respect to said packers.

6. Weil production apparatus, including a packer for separating the production from upper and lower zones in a well bore, a second packer above said upper zone, a first production string adapted to extend through both of said packers in leak-proof relation with respect thereto, said first production string having by-pass means provided with an inlet and outlet adapted to be positioned .'below said lower packer and above said upper packer, respectively, for foy-passing fluid from said lower zone-through said upper zone to a point above said upper packer, a second production string connected to said outlet for conducting fluid fromv said by-pass to the surface of the well bore, said first production string also having an inlet adapted to be positioned between said packers for delivering uid from said upper zone into said first production string and for conducting it through said rst production string to the surface of the well bore independently of the production flowing through said second production string, said production strings :being movable as a unit to shift the positions of said inlets and outlet with respect to said packers.

DEAN F. SAURENMAN.

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