US 3357489 A
Description (OCR text may contain errors)
3,35 PPARATUS AND SAME Dec. 312, 19%? c. c" BROWN MULTIPLE WELL PRODUCTION PACKER A 3 Sheets-$heet METHODS OF POSITIONING THE Filed Feb.
C. C. BROWN ERODULI THODS 01 PO 3,35 7,483 MULTIPLB WELL TION PACKBR APPARATUS AND 5 IT ZONING THE SAME 3 Sheets-Sheet 2";
Filed Feb. l9 1965 ATTORNL-YS Ba 32, ME?
MULTIPLE WELL! PR 0" l METHODS OF F Filed Feb. 19, 195
C. C. BROWN 3,357,439 N PACKER APPARATUS AND IONING THE SAME 5 Sheets-Sheet If IO IT CICIAOGBKOWN INVENTOR. ddmmahf ATTORNEYS United States Patent 3,357,489 MULTIPLE WELL PRODUCTION PACKER AP- PARATUS AND METHODS OF POSITIONING THE SAME Cicero C. Brown, 8490 Katy Road, Houston, Tex. 77024 Filed Feb. 19, 1965, Ser. No. 433,940 9 Claims. (Cl. 166-48) ABSTRACT OF THE DISCLOSURE A multiple production packer apparatus and method of positioning the same in which a lower packer, having means for anchoring the packer within a well bore against movement in both directions, is lowered into the Well bore on a first tubing string; an upper packer is also mounted in a fixed position on the first tubing string so as to be lowered simultaneously with the first packer; the lower packer is then set through manipulation of the first string, after which an upward tension is placed in that portion of the first tubing string between the two packers, following which the upper packer is set by means of lowering a second tubing string and applying the weight of said second string to the upper packer. This abstract is neither intended to define the invention of the application which, of course, is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
This invention relates to new and useful improvements in multiple well production packer apparatus and methods of positioning the same within a well bore.
In multiple production wells, the well bore traverses a plurality of producing zones and well packer apparatus is disposed within the bore to locate well packers at required elevations to seal off each zone from the other. The well fluids from each zone may thus be produced through its own well tubing or production string without intermingling with the well fluids of other zones.
In the simplest form of multiple well production apparatus wherein production from two zones is to be produced, it has been the practice to seta lower well packer, having a single bore, within the well. Thereafter, an upper dual-bore packer is lowered by means of a first tubing string, and the lower portion of such first string projects downwardly from the upper packer to engage and seal with the bore of the lower packer. The engagement of the lower end of the tubing string ordinarily functions to limit the point to which the upper packer can be lowered to thereby locate the upper packer in proper position. However, this procedure necessarily imposes some of the tubing weight upon the lower packer and places that portion of the tubing string between the packers in compression. The assembly is completed by running a second string into the second 'bore of the upper packer and then setting the upper packer.
Although the foregoing apparatus efiectively seals off the production zones and allows each zone to be produced independently, it has the disadvantage of placing that portion of the tubing string between the packers under compression. When under compression, differential pressures or temperature changes cause an undue strain to be placed on this portion of the string, and actual practice has shown that such strain may result in undue movement, which may result in leakage through the bore of the lower packer or in actual breaking or rupturing of said string portion.
It is, therefore, one object of this invention to provide an improved multiple production apparatus in which that portion of the tubing string between packers may be placed under tension and will remain so after the packers are set, whereby the inherent disadvantages which result when such portion is under compression are eliminated.
Another object is to provide an improved multiple production well packer apparatus wherein the lower packer of the assembly is so constructed that it may be set in sealing position by manipulation of the first tubing string, after which an upward strain may be taken on the lower packer to place that portion of the tubing string between said lower packer and an upper packer under tension; said portion remaining under tension after both packers are in final position.
A further object is to provide an improved multiple production well packer apparatus, of the character de scribed, having a lower single bore packer and an upper dual-bore packer which are lowered on a first tubing string; said string extending through the upper packer and having such connection with the lower packer that the lower packer may be moved into set position to lock the lower packer in sealing position against movement in either direction, whereby after setting of said lower packer any desired upward strain may be taken on said tubing string to place it under tension.
A particular object is to provide an improved method of positioning a pair of spaced well packers and a pair of parallel tubing strings within a well bore, which method comprises the lowering of the two packers on a first string and the setting of the lower packer by manipulation of the first string, after which said first string may be placed under tension; the method being completed by the lowering of a second parallel tubing string which is utilized to set the upper packer by imposing its weight thereon.
The construction designed to carry out the invention will be hereinafter described, together with other features thereof.
The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown, and wherein:
FIGURE 1 is a schematic view of a well packer apparatus assembly, constructed in accordance with the invention and illustrating the same disposed within a well bore with a lower packer in its set position,
FIGURE 2 is a similar view illustrating the second parallel well tubing string in place and with the upper well packer in its set position,
FIGURE 3 is a vertical sectional view of one type of dual-bore well packer which may be employed as the upper well packer of the assembly,
FIGURE 4 is a vertical sectional view taken on the line 44 of FIGURE 3, but with packer in set position,
FIGURE 5 is an elevation showing one of the gripping slips of the upper packer,
FIGURE 6 is a view, partly in section and partly in elevation, of the lower well packer of the assembly, with said packer in unset position, and
FIGURE 7 is a similar view with said lower packer in set position.
In the drawings, the numeral 10 designates a well bore which traverses an upper wall formation W1 and a lower producing formation W2. The usual well casing 11 is disposed within the well bore and has fluid inlet perforations or openings 12 opposite the upper formation W-1 and similar inlet perforations 13 opposite the lower formation W-2. The Well casing 10 extends to the surface and has the usual tubing head 14 connected therewith.
The improved well packer apparatus of the present invention includes an upper dual-bore packer generally indicated at A and a lower single-bore well packer indicated at B. The lower well packer B is adapted to be positioned between the producing formations W-l and W-2, and
when said packer is in set position, the producing formations are separated. The upper packer A is adapted to be positioned above the upper formation W-1.
A first tubing string T-l extends through and is connected to the upper well packer A. The tubing string T-l has a section indicated at S which projects downwardly from the upper packer and which extends into the bore of the lower packer B and is connected therewith. As will be explained, both packers are lowered into position within the well bore by means of the first tubing string T-l. The final position of the packers in the bore is illustrated in FIGURE 1, with the lower packer B being shown in set position.
The lower packer is set by manipulating the first tubing string; at this time the upper packer A is not in set position. The lower packer is anchored against movement in either direction and, therefore, after it is set, an upward strain is taken on the tubing string T-l. This places that portion S of the tubing string, which is located between the packers, in tension. After the desired tension has been placed in the section S by means of such upward strain, the first tubing string is supported at the surface by means of the usual hangers or slips 14a within the tubing head 14.
Thereafter, a second tubing string T-2 is lowered into .the well casing and is adapted to engage within and communicate with a second bore provided in the upper packer. The upper packer A is so constructed that the weight of the second tubing string T-2 may be imposed thereon to move the upper packer into its setor sealing position. The tubing string T-2 is then supported by the well-known hanger or slip 1412' within the tubing head 14, after which the upper end of the well is closed in by mounting the usual closure 15 upon the tubing head and providing suitable control valves 15a in each tubing stringy When the apparatus is within the well bore, as shown in FIGURE 2, production from the lower zone W-2 may flow upwardly through the first tubing string T-l. At the same time, production from formation W1 may flow upwardly to the surface through the second tubing string T2. With the apparatus within the well, the section S of the tubing string T-1, which is that portion extending between the two packers, is under a tension. When under tension, the tubing is prevented from moving or working by reason of differential pressures or temperature changes acting thereon. Such motion or working of the section may interfere with the seal between the lower end of section S and the lower packer or, if severe enough, may cause actual rupture or breakage of said section. Actual practice has shown that when the section S between the packers is under compression, the section may undergo some motion under changing pressure and temperature conditions, which, as above noted, is undesirable.
The specific construction of the well packers employed in the apparatus is subject to variation. One type of upper multiple bore well packer A which has been found suitable is shown in FIGURES 3 through 5, while a satisfactory lower well packer B is illustrated in FIGURES 6 and 7.
Referring to FIGURE 3, the upper dual-bore packer assembly A includes an upper body section 20 having vertical parallel bores 21 and 22 extending therethrough. The bore 21 is counterbored at 23 nearer its upper end to form an annular shoulder 24. The first tubing string T-l is connected to a tubular portion 25 through coupling 26, and said portion extends downwardly through the bore 21. As will be described, the portion 25 extends throughout the length of the upper packer assembly and when connected to tubing T-l, acts as an auxiliary mandrel for said packer assembly. The lower part of the coupling 26 is disposed in the counterbore 23 and is normally rotatably connected by shear pins 26a (FIG..4) in the section 20 engaging an external groove 26b in the coupling; when in connected position, the lower end of the coupling engages the shoulder 24. During setting, the pins 26a are sheared to permit downward movement of section 20 relative to the tubular portion 25 of tubing string T-l, as will be hereinafter explained.
An elastic packing element 27, having its ends confined by end plates 28 and 29, is located below the upper section 20. A vertical bore 21a in the packing element and suitable openings in the end plates are aligned with the bore 21 in body section 20 so that the tubular portion or mandrel 25 may extend downwardly therethrough. A second parallel bore 22a in the packing element and suitable openings in the end plates are in vertical alignment with the second bore 22 in said upper section 20. A main mandrel or support tube 30 having its upper end threaded into the bore 22 extends downwardly through the packing element 27, and then continues some distance therebelow with its lower end open so that fluids may flow upwardly therethrough and into bore 22. The mandrel or tube 30 forms the main support element for the assembly.
An expander body 31 below the elastic packing element 27 is supported upon an external annular shoulder 32 on the mandrel or tube 30. With this construction, the elastic packing element and the expander body 31 are confined between shoulder 32 and the lower end of the upper section 20, but the upper body section may undergo downward movement relative to the expander when the packer element is deformed. The expander body has parallel bores 21b and 22b through which thetubular portion 25 and mandrel 30, respectively, extend. As shown in FIG- URE 4,'the expander body is formed with a pair of inclined surfaces 33, which are preferably located one hundred eighty degrees opposite each other, and each surface coacts with an anchoring means which may be the usual gripping slip or member 34. Upon downward movement of the expander with respect to the gripping slips 34, said slips are moved radially outwardly into gripping engagement with the wall of the well casing 10; opposite relative movement releases said slips.
Spaced below the slip expander body 31 is a slip carrier 35 which has parallel bores 21c and 220 for receiving the tubular portion 25 and mandrel tube 30, respectively. The portion 25 extends downwardly through the bore 21c and has an annular enlargement 36 which engages an internal shoulder 37 formed in said bore. A con necting pin 38 secures said tubular portion to the slip carrier 35 and the tubing string T-l, of which said portion forms a part, is thereby also connected to said carrier. The mandrel tube 30 extending through the second bore 22c of the slip carrier is enlarged at its lower end to provide a supporting shoulder 39 which engages the lower end of the slip carrier.
The upper peripheral portion of the slip carrier 35 is formed with T-shaped slots 40 which receive T-shaped connecting elements 41. formed on the lower end of the gripping slips 34. Such connection (FIGS. 4 and 5) limits vertical movement while allowing radial motion of each gripping slip relative to said carrier.
The lower end of the tubular portion 25 of string T1 projects downwardly below the slip carrier 35 and is connected by a coupling 42 with the tubing section S which also forms a continuation of the tubing string T-1. The lower portion of the section S is connected by means of another coupling 43 (FIG. 6) with the main supporting mandrel 44 of the lower well packer B.
As will be explained, the upper packer A and lower packer B are lowered together on the first tubing string. The lower packer is then set and thereafter tubing T-1 holds the upper packer in position in its unset position by means of connecting pin 38 and shear pins 26a. The second tubing string T-2 is then lowered so that its lower portion enters the bore 22 in the upper section 20 of said packer A. A suitable pin and J-slot connection 45 is made between this second tubing string and said upper section 20. The lower end of the tubing string T-2 engages a shoulder 46 formed within the bore 22 and thereafter the weight of tubing T-2 may be imposed downwardly upon the upper section 20.
Since the slip carrier 35 is directly connected to the tubular portion 25 of the tubing string T-1 through pin 38, the carrier and slips 34 are held stationary. Imposition of the weight of the tubing string T-2 shears the pins 26a and then urges section 20 downwardly relative to said portion 25, thereby applying downward force to packing element 27 and expander body 31, whereby said expander body moves downwardly with respect to the gripping slips 34. Since the gripping slips are stationary, such action moves said slips radially outwardly into gripping position. Continued imposition of weight on the upper section after the slips are set results in deforming of the elastic packing element 27 into sealing position with the wall of the well casing 10, as illustrated in FIGURE 4. It might be noted that during the setting operation, the mandrel tube 30, which has connection with the upper section 20 of the packer, slides downwardly through the packing element, the expander body and the slip carrier.
The lower packer B may take different specific forms, and one type which has been found satisfactory is illustrated in FIGURES 6 and 7. This is substantially similar to the packer disclosed in my co-pending application, Serial No. 299,982, filed Aug. 5, 1963, now Patent No. 3,294,172, issued Dec. 27, 1967. The major requirement of the lower packer in this particular assembly is that it be capable of being set by manipulation of the first tubing string T1, and that once set, it will hold its position against movement in either direction. With this type of packer, after it is set and locked against movement in either direction, an upward strain may be taken on the tubing T-1 to place that portion of the tubing S, which is located between the packers, under a tension.
The preferred type of lower packer B includes the main supporting mandrel 44 which is coupled through the collar 43 to the intermediate or connecting section S of the tubing string T-1. The mandrel 44 constitutes the main support of the device and is formed with an external shoulder 50 intermediate its ends. As will be explained, this shoulder functions as a support during lowering, and also provides a means for applying an upward force to permit unsetting of the assembly.
Spaced downwardly from the shoulder 50, the mandrel is formed with a series of external threads 51 which are left-hand buttress type threads. The upper surface of each thread is substantially flat, lying in a plane which is normal to the axis of the mandrel, while the loWer surface of each thread is directed in an upward and outward direction. These threads are adapted to interconnect with a plurality of locking dogs or segments 52 having complementary buttress type left-hand threads 53 formed thereon.
The locking segments or dogs are mounted within the upper portion of a tubular housing 54, which housing has a reduced downwardly projecting extension 55 surrounding the exterior of the mandrel 44. The extension 55 is formed with J-slots 56. which are adapted to be engaged by outwardly projecting pins 57 secured in the mandrel 44. When the pins 57 are engaged in their respective J- slots, the housing 54 which carries the locking dogs is coupled or connected to the mandrel 44.
Each locking dog 52 in non-rotatable with respect to the housing, and rotation thereof is prevented by the interengagement of a notch 58 with a key 59 secured within said housing. The locking dogs 52 are urged inwardly toward the mandrel by means of an annular spring 60 which encircles all of the segments and resiliently holds them in position against the mandrel. When the J-slot connection is released and the mandrel 44 is moved downwardly with respect to the segments 52, the buttress type threads 51 on the exterior of the mandrel may slide downwardly and ratchet into the complementary threads 53 of the locking segments. Thus, engagement is effected by a straight longitudinal downward movement of the mandrel.
Secured within the upper end of the housing and mounted for radial movement therein is a plurality of spring pressed friction blocks 61. The upper end of the housing 54 is connected to an anchoring means in the form of a lower expander 62, a plurality of gripping slips 63 carried by a tubular body 63a, and an upper expander 64. The upper expander has an upwardly extending sleeve 68 and encircles the mandrel, being normally supported on the shoulder 50 of mandrel 44. When the expanders 62 and 64 are disposed behind the slips 63 (FIG. 7) the assembly is locked against movement in either direction within the well bore.
A packing assembly 65 includes an elastic packing ring 66 which is confined at its lower end by a ring 67a supported upon an external shoulder 64a on the upper expander and which is confined at its upper end by a collar or abutment 67. The abutment surrounds the sleeve 68 of the upper expander 64, and its upper surface is normally engaged by supporting ring 68a on the sleeve. Above the abutment and secured thereto is an annular sealing body having its bore 70a in communication with the bore of the sleeve 68.
The bore of the body 70 and sleeve 63 is adapted to be closed by a packing means 69 which is mounted below the coupling 43 on the mandrel 44. When the J-slot connection 56, 57 is engaged, the packing 69 is located above the body 70 and by reason of ports 71 formed in the upper expander 64 below the lower end of the sleeve 68, a by-pass of fluid past the packer and through the sleeve to the area above the packing rings may occur. This is the position of the packer during lowering.
In the operation of the lower packer B, the device is lowered into the well on tubing T1 and the packer is in unset position (FIG. 5). The mandrel 44 is coupled to the housing 54 by the J-slot connection 56, 57, and since the housing is attached to the lower expander 62, this effectively latches the lower expander to the mandrel. At the same time the upper expander 64 is supported upon the external shoulder 50 of the mandrel, which shoulder limits the downward movement of the upper expander on the mandrel and thereby assures that expanders 62 and 64 are held sufliciently far apart to prevent any radial outward movement of the gripping elements during the lowering operation. As the packer is lowered, the friction blocks 61 drag on the wall of the r pipe or casing 10 and the packing ring 66 is in a nonsealing or retracted position; also at this time the seal 69 is spaced above the sealing body 70 so that there is a by-pass of fluid upwardly around the mandrel to the area above the packer.
To set the packer, the tubing string T-l is rotated a slight distance to the left to disconnect the J-slot connection 56, 57. Thereafter, a downward movement of the mandrel 44 with respect to the packer may occur, and as said mandrel moves downwardly, the friction blocks 61 maintain the lower expander stationary; the slips 63, which are housed within the slip carrier 63a, are also maintained substantially stationary. When the mandrel has moved downwardly a sufficient distance, the seal 69 enters the bore of the body 70 at the upper end of the packer to close the by-pass, and the lower end of the coupling 43 engages the body 70 which is directly connected to the upper abutment 67. The weight of the tubing string T-l may then be applied to the abutment 67, and this force is transmitted through packing ring 66 to the upper expander 64. Through the coaction of the inclined surfaces of the expanders 62 and 64 with the slips 63, the slips are moved radially outwardly into gripping engagement with the pipe. Following the anchoring of the gripping elements to the wall of the pipe or casing, further imposition of tubing weight upon the upper end of the abutment 67 deforms the packing ring 66 into sealing engagement with the pipe wall.
At the same time that the mandrel 44 has been moved downwardly to effect a setting of the gripping elements and a deformation of the sealing rings, the buttress type threads 51 on the mandrel have ratcheted downwardly into the locking segments 52. After the threads are engaged and in order to assure that the packer will remain in its set position, the tubing T-2 is rotated slightly to the left, possibly about one-half turn, and this causes the upper beveled end 52a of each locking dog 52 to be moved upwardly on the mandrel to the position shown in FIGURE 7, whereby these upper surfaces are engaged and confined by an inwardly beveled shoulder 73 formed within the housing 54. This assures that the threads of the dogs are maintained in engagement with the threads of the mandrelso that the packer is locked in its set position. The slight left-hand rotation of the tubing, which moves the segments into finally locked position, is not sufiicient to uncouple any connection in the tubing string T1.
Any pressureabove the packer which would tend to displace the same from its anchored position acts downwardly against the packing ring 66, and then downwardly against the upper expander, thereby driving the upper expander into tighter gripping contact with the slips. Similarly, any pressure from below the assembly which would tendto displace the same upwardly will act upwardly against the seal 69, which force is transmitted through the mandrel 44 to pull upwardly on the locking dogs; this upward force is transmitted to the lower expander 62 which moves further behind the gripping slips 63 to urge them into tighter gripping engagement. The packer is thus capable of holding its anchored position against high differential pressures across the packer.
After the packer is in set position, an upward strain may be taken on the tubing string T-1, which will impart an upward pull on the mandrel 44 of packer B. Such upward force, applied to the locking dogs 52 and housing 54, is transmitted to the lower expander 62 which urges the slips into tighter gripping engagement. Thus, any desired tension may be placed within the connecting section S of the tubing string T-1, which is that section between the upper and lower, Packers.
Release of the lower packer B is effected by rotating the tubing T1 and mandrel 44 to the right, and at the same time picking up the weight of the tubing. The locking segments or dogs 52 are held against rotation through the key and slot arrangement 58, 59, the friction blocks 61 assisting in preventing rotation of the housing; nonrotation of the dogs is also helped, during initial rotation of mandrel 44, by the set slips which are maintained in their wedged positions by the lower expander 62; since the expander cannot move and is connected to the housing, it holds the housing stationary. Continued rotation of the mandrel to the right, which is in a direction which will not uncouple any of the collars in the string, the lefthand threads are actuated to cause the mandrel to move upwardly with respect to the. locking dogs 52. As soon as the threads become disconnected, a straight upward pull on the string T-l and mandrel 44 moves the shoulder 50 on the mandrel beneath the upper expander 64 and lifts said expander upwardly with respect to the gripping slips to allow retraction of the slips; continued upward movement removes the packer from the well bore. As the mandrel was initially moved upwardly, the downward force on the sealing element or ring 66 was relieved and said sealing ring moved to retracted or nonsealing position.
In carrying out the method of placing the well packers and tubing strings within the well bore, the upper and lower packers, each in its unset position, are lowered into the well bore and properly located by means of the first tubing string. The tubing string T-1 is then manipulated to set the lower packer B and anchor it against displacement in either direction. The tubing string T1 remains connected to the lower packer, even though the latter is in its set position, thereby permitting an upward strain to be applied to said tubing string T-1, whereby the section S of tubing string T-l between the packers is placed under a desired tension. Such tension is particularly advantageous when said section is subjected to pressure and temperature changes.
Thereafter, the second tubing string T-2 is lowered into the second bore 22 of the upper packer A and the string is utilized to impose weight upon the upper end of the upper packer. This moves the upper packer into set position without disturbing the tension which was previously placed within the section S of tubing string T1. Following final suspension of tubing strings T-l and T-2, the upper end of the well bore is closed by closure 15 and production from each of the zones takes place through the respective tubing strings with fiow being controlled by valves 15a.
As has been noted, the section S of the tubing string T-1, which is located between the upper and lower packers, is subject to pressure differentials and to temperature changes. -If this section is under compression, as has been the practice in the past, it is liable to undergo undesirable motion or shitting due to elongation. Such motion may interfere with the seal '69 between tubing T'1 and the lower packer B or, if severe enough, may result in actual breaking or rupturing of the tubing string section S. Maintaining the section S under tension avoids these difficulties.
Although the particular well packers shown and described have been found particularly adaptable for the apparatus, the specific details of construction are subject to variation. Insofar as the lower well packer is concerned, it is only necessary that this be a packer which may be set by manipulation of the first tubing string T 1,.and that it be a packer which will anchor in place against both upward and downward movement. It is, of course, also necessary that the lower packer remain connected to the tubing string after setting so that the necess-ary upward strain may be applied to the tubing string T1, andthereby place the desired tension in its section S.
The foregoing disclosure and description of the invention is illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made within the scope of the appended claims without departing from the spirit of the invention.
What I claim is:
1. A multiple production well packer apparatus for a well bore which traverses at least two well producing zones and including,
a lower well packer in said well bore positioned between the lowermost producing zone and the zone thereabove and sealing with the well bore,
an upper well packer in the well bore positioned above the said upper zone and sealing with the well bore,
a first tubing string extending downwardly through the upper well packer and into the lower packer and having sealing engagement with both packers whereby production from the lowermost zone is conducted to the surface from the lower zone through said first string,
means mounting the upper packer in a predetermined position on said first tubing string,
means connecting the lower packer to the first tubing string whereby an upward tension on the first string will move the upper packer upwardly relative to the lower packer to place that portion of said first tubing string between the packers under a predetermined tension to prevent pressure and temperature from affecting said portion,
means for thereafter setting said upper packer without relieving the tension in that portion of the first string which extends between the packers, and
a second tubing string also extending downwardly to the upper well packer and having communication with the area between said packers whereby production from the zone below the upper packer is conducted to the surface from said zone through said second string.
2. A multiple production well packer apparatus as set forth in claim 1, wherein the means for setting said upper well packer includes setting means coacting with the second tubing string to move said upper well packer into said position by imposing the weight of said second string upon said packer.
3. A multiple production well packer apparatus as set forth in claim 1, wherein said lower well packer includes setting means coacting with the first tubing string to move said lower packer into set position by manipulation of said first string,
said'lower well packer also having anchoring means for anchoring said packer against movement in both directions within the well bore when in its set position.
4. A multiple production well packer apparatus as set forth in claim 1, wherein said lower well packer includes setting means coacting with the first tubing string to move said lower packer into set position by manipulation of said first string,
said lower well packer also having anchoring means for anchoring said packer against movement in both directions within the well bore when in its set position, and
said upper packer including setting means coacting with the second well tubing string to move said upper packer into set position by imposing the weight of said second string upon said packer.
5. A dual-production well packer apparatus for a well bore which traverses a lower producing zone and an upper producing zone, said apparatus including,
a lower weight-set packer positioned between the two producing zones and having anchoring means for anchoring the packer against displacement in either direction within the well bore,
an upper weight-set packer positioned above the upper producing zone and having anchoring means for anchoring the packer within the well bore,
a first tubing string extending through the upper packer and extending downwardly to the lower packer and having communication with the lower producing zone,
means connecting said upper packer in a fixed position on said first tubing string,
coacting means on said lower packer and said first string for connecting the string and packer to permit lowering of the packer by means of said first string,
said connection being actuated by manipulation of said first string to allow imposition of the weight of said string upon the packer to set the packer, after which an upward pull may be applied to raise the upper packer relative to the lower packer to thereby impart tension to that portion of the first tubing string between the packers,
a second tubing string extending to the upper packer and having communication with the upper producing zone, and
coacting means on the upper packer and the second tubing string for setting said upper packer by the imposition of the weight of said second string upon said packer.
6. A dual-production apparatus as set forth in claim 5, wherein said upper well packer includes a pair of parallel bores,
one of which has the first tubing string extending therethrough and the other of which receives the second tubing string, and
also wherein the lower well packer has a single bore into which the first tubing string extends. 7. The method of positioning a lower well packer, and an upper well packer and two production tubing strings within a well bore which traverses at least two produc ing zones, said method including lowering the upper and lower well packers into the well bore on the first tubing string to position the lower packer between a lower zone and an upper zone and position the upper packer above the upper zone, manipulating said first tubing string to set the lower packer and anchor it against movement in both directions, said first string remaining connected to said lower packer after the latter is in anchored position,
pulling an upward strain on said first tubing string to raise the upper packer relative to the lower packer to place that portion of the string between the packers under tension,
thereafter lowering a second tubing string within the well bore and into engagement with the upper packer, and
setting the upper well packer by manipulating the second tubing string.
8. The method as set forth in claim 7, wherein the manipulation of the first string which sets the lower packer comprises a rotation and downward movement of the first string with respect to the lower packer whereby the weight of said first string effects said setting, and
also wherein the manipulation of the second string which sets the upper packer comprises the downward movement of said second string with respect to the upper packer whereby the weight of said second string effects said setting.
9. The method as set forth in claim 7, wherein removal of the apparatus from the well bore is accomplished by removing the second tubing string from the well bore to relieve the upper packer from the weight thereof to permit unsetting of said upper packer,
rotating the first string relative to the lower packer to release it from its set position, and
thereafter removing the first tubing string to withdraw both well packers from the well bore.
References Cited UNITED STATES PATENTS 2,893,492 7/1959 Brown l66129 X 2,903,066 9/1959 Brown l66187 X 2,950,761 8/1960 Brown et al l661 19 2,973,035 2/1961 Brown l66l34 X 2,990,882 7/1961 Brown 166-119 3,011,552 12/1961 Rhodes et al l6685 X JAMES A. LEPPINK, Primary Examiner.