US3454096A - Crossover device for parallel pipe strings - Google Patents

Description

Sheet H. U. GARRETT cRosso'vER DEVICE FOR PARALLEL PIPE STRINGS AJuvly 8, 1969 Filed Jan. 29, 1968 Arrow/ys July 8 1969 l H. u. GARRETT 3,454,096

I CROSSOVER DEVICE FOR PARALLEL PIPE STRINGS med Jan. 29, 196s sheet 2 of /Ofu- "rh-a Hfwmmf" 7. l HY ATT ORNEKS United States Patent Ar U.S. Cl. 166-242 7 Claims ABSTRACT F THE DISCLOSURE A crossover device adapted for connection into a plurality of parallel pipe strings to provide means for opening communication `between the pipe strings when necessary to establish cross-flow between the pipe strings.

In the operation of oil and gas wells, it is frequently necessary, after the wells have been in operation for various periods of time, to perform various operations in the production strings to improve the functioning thereof. Such operations may include installing or actilvating artificial lift equipment, cleaning out paraffin deposits, removing accumulating sand and other detritus which may plug the production pipe string, and various other operations familiar to those engaged in oil well operations.

While the performance of such servicing operations in wells located on land usually involve various diticulties and complexities, the latter are greatly increased in wells in offshore locations. To meet the service and workover requirements for such Wells with minimum diiiiculty and expense, various types of servicing systems have been devised.

In one such system installed as part of the original well equipment, parallel pipe strings are run into a well, one or more of such pipe strings being equipped to function as production strings and one or more additional pipe strings equipped to function as service strings, the pipe strings being frequently interchangeable as to function. By providing a service pipe string in communication with a production pipe string, fluids under pressure may be circulated from one string to the other to remove obstructions, to clean out sand and paraiiin, and to perform other operations in which such circulating uids may be useful.

In such multiple string systems, an open crossover connection -will usually be provided between the strings adjacent their lower ends so that initially a uid circulation path may be established between the strings as may be required. v

However, it is found that in the course of operation, plugging by parain or sand, or some other defect or difficulty may occur at one or more points in the production string above the lower ends of the pipe strings and it -becomes necessary in some manner to establish cross-flow between the pipe strings at points below or between such plugged -or obstructed points, so that pressure uid may be circulated from the -service string into the production pipe string at the elevation most effective to eliminate the difliculty.

The present invention is directed to a form of crossover device adapted to meet and overcome such prob- 3,454,096 Patented July 8, 1969 ice lems and comprises a body having a plurality of parallel bores and construction to be installed in a corresponding plurality of parallel pipe strings. The body of the device is provided with crossover passage means disposed to connect the several bores, but which initially is sealed oli` from communication with at least one of said bores, so that upon opening communication between the latter and the crossover passage, as by operation of a perforating device in the sealed-olf bore, cross-communication may be established between the several pipe strings.

The crossover device includes a positioning or indexing seat for receiving a perforating tool or the like, in a manner to index the'perforating tool at a position enabling it, -When actuated, to form an opening through the wall of the sealed-oli bore into the crossover passage.

In the case of a dual pipe string system, an opening will ordinarily -be pre-formed between the -bore of the production string and the crossover passage, and communication established with the service pipe string, when required, by perforating the latter to provide communication with the crossover passage.

Ordinarily, a plurality of such crossover devices will be initially installed at longitudinally spaced points along the parallel strings, so that a plurality of spaced crossover points will be provided at 4which fluid communication between the several pipe strings may be established as determined by conditions fwhich may develop during the course of operation of the well.

Other and more specific objects and advantages of this invention will 'become more readily apparent from the following detailed description when read in conjunction with the accompanying drawing which illustrates one useful embodiment in accordance with this invention.

FIG. 1 is a longitudinal -sectional view of a parallel dual pipe string system having installed therein a crossover device in accordance with this invention, and showing positioned in one of said pipe strings a perforating tool in position to form a perforation to establish cornmunication with the crossover passage in the device;

FIG. Z is a View similar to FIG. 1, showing the perforation formed by the perforating tool;

FIG. 3 is an elevational view, partly in section, showing a dual pipe string system in a well, and provided with a pluurality of longitudinally spaced crossover devices in accordance with this invention; and

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 2.

Referring iirst to FIG. 3, there is shown a dual parallel pipe system, designated generally by the letter S, installed in a well bore W. System S comprises a pair of parallel pipe strings 10 and 11. Pipe string 10 may be designated for purposes of this description as a production pipe string, and pipe string 11 as the service pipe string. Adjacent their lower ends pipe strings 10 and 11 are connected by an open crossover connection 12 having a pair of parallel passage means 13 and 14 defining downward extensions of the respective pipe strings 10 and 11. The passage means 13 and 14 are closed by means of upwardly opening check valves 15 and 16, respectively, commonly referred to as standing valves through which production fluids may enter the respective pipe strings from producing formations intersected by the well bore.

A number of crossover devices, designated generally by the letter C and constructed generally in accordance with this invention, are positioned at vertically spaced points along the pipe system connected into both pipe strings and 11. As best shown in FIGS. l, 2 and 4, each of these crossover devices C comprises a generally tubular body, designated generally by the numeral 20, comprising telescopically interconnected upper and lower body sections 21 and 22, respectively. Body 20 is provided with a pair of parallel sleeves 23 and 24 having the respective bores 23a and 24a coaxial, respectively, with pipe strings 10 and 11. The upper ends of sleeves 23 and 24 are formed to provide internally threaded sockets 25 and 26, respectively, which connect into the respective pipe strings 10 and 11. The lower ends of sleeves 23 and 24 likewise communicate with internally threaded sockets 27 and 28, respectively, provided in lower body section 22. The upper portion of lower body section 22 is dened yby an annular wall 29 which is threadedly connected to upper body section 21 at 30 and surrounds sleeves 23 and 24 to define an annular crossover passage 31 extending circumferentially about both sleeves 23 and 24. The wall of sleeve 23 is initially provided with a pre-formed opening 32 placing bore 23a into communication -with crossover passage 31. The other sleeve 24 is imperforate and, therefore, initially out of communication with the crossover passage but is placed in communication therewith in a manner to be subsequently described.

Sockets 27 and 28 in lower body section 22 are adapted to receive the threaded upper ends of tubular latch mandrels 33 and 34, respectively, the lower ends of which carry externally threaded pins 35 and 36, respectively, for connection to lower sections of the respective pipe strings 10 and 11. Mandrels 33 and 34 are provided with enlarged bore portions 37 and 38, respectively, coaxial with the bores of the mandrels and the respective bores 23a and 24a and their related pipe strings 10 and 11. The enlarged bore portions 37 and 38 are each dened by a lower end "wall 39 and an upper end wall 40, the latter being downwardly and inwardly bevelled, as shown. Enlarged bore portions 37 and 38 provide latching seats for reception of perforating tools, as will be subsequently described.

Operation of the dual pipe `string system may require that iluid circulation be established between pipe strings 10 and 11 at points above crossover connection 12, for whatever purposes needed. In such case, a perforating tool of generally conventional design, designated generally by the numeral 45, will be run through the bore of service pipe string 11 to a position in bore 24a opposite passageway 31. To accomplish this positioning of the perforating tool, the lower end of the latter will be conneced to a known form of cam latch, designated generally by the numeral 46, which forms no part of the present invention but is illustrated in a form which enables perforating tool 45 to be latched into bore enlargement 38 in a position to dispose the perforating element, indicated at 47, `adjacent the wall of sleeve 24 and opposite passageway 31. It will be understood that the perforating tool, the latch mechanism, and the fishing head 49 by which the tool is inserted into and withdrawn from pipe string 11, are generally conventional and the details thereof do not form any part of the present invention.

When perforating tool 45 has been positioned as described and illustrated, it will be tired in a generally conventional manner, either by electrical or hydraulic means, so as to cause the perforating element 47 to form a perforation 48 through the wall of sleeve 24 to place bore 24a in communication with crossover passage 31. When this has occurred it will be evident that iluid communication will now be established through crossover passage 31 between bores 23a and 24a, so that pressure uid may be circulated down through pipe string 11, thence through crossover device C into the bore of pipe string 10, and thence back toward the surface, in order to lift or wash out any obstruction which it is desired to remove from the production pipe string 10.

By employing a number of crossover devices C at a plurality of points along the pipe string system, circulation may thus be established at any one or more of these several points between these pipe strings.

It will be understood that the crossover devices in accordance with this invention may be made to accommodate more than two parallel pipe strings. In each instance, however, the crossover device will incorporate as many parallel sleeves as may be required to connect it to the several pipe strings. At least one of the sleeves initially will be imperforate and out of communication with the crossover passage, so that communication may be subsequently established, as required, between the several pipe strings. Initially only one of the pipe strings will have a pre-formed opening communicating with the crossover passage, although it may be useful in some cases, where more than two pipe strings are involved, to have more than one of the bores in the crossover device initially open to the crossover passage.

It will -be understood that various other modifications and variations may be made in the details of the illustrative embodiment within the scope of the appended claims but without departing from the spirit of this invention.

What I claim and desire to secure by Letters Patent is:

1. A crossover device for connecting parallel pipe strings, comprising:

(a) a body having a plurality of parallel bores therethrough for connection into a corresponding number of parallel pipe strings,

(b) a lateral passage in the body extending between said bores,

(c) an opening communicating said passage with one of said bores, and

(d) means in each of the other bores constructed and arranged to locate a perforating tool therein in a position to provide, when actuated, an opening cornmunicating that one of said other bores with said passage.

2. A crossover device according to claim 1, wherein the number of said parallel pipe strings is two.

3. A crossover device according to claim 1, wherein said means comprises cylindrically enlarged portions of said bores defining seats for latching engagement by said perforating tool.

4. A crossover device according to claim 1, wherein `said passage comprises an annular passage extending circumferentially of said body exteriorly of said bores.

5. An equipment system for wells, comprising the combination of:

(a) a plurality of parallel pipe strings extending into a Well bore,

`(b) an open crossover connection member connecting said pipe strings adjacent their lower ends,

(c) said connection member including extensions coaxial respectively with said pipe strings and having upwardly opening check valve means therein,

(d) crossover devices connecting said pipe strings at one or more vertically spaced points above said crossover connection member, each of said crossover devices comprising:

(i) a body having a plurality of parallel bores therethrough for connection into the several said pipe strings,

(ii) a lateral passage in the body extending between said bores,

(iii) an opening communicating said passage with one of said bores, and

(iv) means in each of the other bores constructed and arranged to locate a perforating tool therein in a position to provide, when actuated, an opening communicating that one of said other bores with said passage.

6. An equipment system according to claim 5, wherein 3,012,608 12/ 1961 McLaren 166-52 the number of said pipe strings is two. 3,050,121 8/ 1962 Garrett et al. 166--21 X 7. In an equipment system according to claim 5, said 3,054,456 9/ 1962 Hammaker 166-102X means comprising a cylindrically enlarged portion of said 3,086,592 4/ 1963 Hach 166-67 X bore dening a seat for latching engagement -by said 5 3,149,671 9/ 1964 Alexander 166-55.1 X perforating tool.

References Cited DAVID H. BROWN, Primary Examiner.

UNITED STATES PATENTS Us' CL XR 2,923,357 2/1960 Dafn 166-102 166-102, 115, 314

2,939,533 6/1960 Coberly 16s-242x 1

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