Tubing/casing connection for U-tube wells

Abstract

A tubing/casing connection for U-tube wells. In a described embodiment, a tubular string connection system includes a first tubular string having an expanded entry guide; and a second tubular string having an end guided into the first tubular string by the entry guide.

1 . A tubular string connection system, comprising: 
 a first tubular string having an expanded entry guide; and    a second tubular string having an end guided into the first tubular string by the entry guide.    
   
   
       2 . The system of  claim 1 , wherein the first tubular string is positioned in a first wellbore, and the second tubular string is positioned in a second wellbore.  
   
   
       3 . The system of  claim 1 , wherein the entry guide includes at least one inclined surface for guiding the second tubular string into the first tubular string.  
   
   
       4 . The system of  claim 3 , wherein the inclined surface is an external surface on an outer end of the entry guide.  
   
   
       5 . The system of  claim 3 , wherein the inclined surface is an interior surface of the entry guide.  
   
   
       6 . The system of  claim 1 , wherein the entry guide is expanded by applying a pressure differential across a wall of the entry guide.  
   
   
       7 . The system of  claim 1 , wherein the entry guide is expanded by inflating a membrane within the entry guide.  
   
   
       8 . The system of  claim 1 , wherein an outer end wall of the expanded entry guide is cut through from an interior to an exterior of the entry guide.  
   
   
       9 . The system of  claim 1 , wherein an outer end wall of the expanded entry guide is cut through from an exterior to an interior of the entry guide.  
   
   
       10 . The system of  claim 1 , wherein the second tubular string includes a sheath protecting a seal on the second tubular string, the sheath displacing to uncover the seal when the second tubular string engages the expanded entry guide.  
   
   
       11 . A method of connecting first and second tubular strings in a well, the method comprising the steps of: 
 providing an expandable entry guide on the first tubular string;    positioning the entry guide in the well, and then expanding the entry guide; and    guiding the second tubular string into the first tubular string.    
   
   
       12 . The method of  claim 11 , wherein the providing step further comprises providing an inclined surface on the entry guide, and wherein the guiding step further comprises using the inclined surface to guide the second tubular string into the first tubular string.  
   
   
       13 . The method of  claim 11 , wherein the guiding step further comprises releasing a protective sheath to thereby uncover a seal on the second tubular string.  
   
   
       14 . The method of  claim 13 , further comprising the step of sealingly engaging the seal within the first tubular string, thereby providing sealed communication between the first and second tubular strings.  
   
   
       15 . The method of  claim 13 , wherein the releasing step further comprises releasing the sheath from a latch carried on the second tubular string.  
   
   
       16 . The method of  claim 15 , further comprising the step of engaging the latch with a profile in the first tubular string, thereby securing the second tubular string to the first tubular string.  
   
   
       17 . The method of  claim 11 , further comprising the step of securing the second tubular string to the first tubular string.  
   
   
       18 . The method of  claim 17 , wherein the securing step further comprises engaging a profile formed within the first tubular string.  
   
   
       19 . The method of  claim 18 , wherein in the profile engaging step, the profile is formed within the entry guide.  
   
   
       20 . The method of  claim 17 , wherein the securing step further comprises expanding the second tubular string within the first tubular string.  
   
   
       21 . The method of  claim 17 , wherein the securing step further comprises engaging a latch on the second tubular string with the first tubular string.  
   
   
       22 . The method of  claim 17 , wherein the securing step further comprises engaging a latch with a profile.  
   
   
       23 . The method of  claim 11 , further comprising the step of cutting through an outer end wall of the entry guide.  
   
   
       24 . The method of  claim 23 , wherein the cutting step further comprises guiding a cutting tool using an inclined surface formed on the outer end wall.  
   
   
       25 . The method of  claim 23 , wherein the cutting step further comprises cutting inwardly through the outer end wall.  
   
   
       26 . The method of  claim 23 , wherein the cutting step further comprises cutting outwardly through the outer end wall.  
   
   
       27 . The method of  claim 23 , wherein the cutting step further comprises cutting through a check valve.  
   
   
       28 . The method of  claim 27 , further comprising the step of cementing the first tubular string in the well by flowing cement outwardly through the check valve prior to the cutting step.  
   
   
       29 . The method of  claim 23 , further comprising the step of guiding a cutting tool toward the outer end wall using at least one radioactive source attached to the first tubular string.  
   
   
       30 . The method of  claim 29 , wherein the cutting tool guiding step further comprises detecting a spaced apart series of the radioactive sources.  
   
   
       31 . The method of  claim 29 , wherein in the cutting step the first tubular string is positioned in a first wellbore, and wherein the cutting tool guiding step further comprises guiding the cutting tool through a second wellbore.  
   
   
       32 . The method of  claim 11 , wherein the positioning step further comprises positioning the first tubular string in a first wellbore, and wherein the guiding step further comprises displacing the second tubular string in a second wellbore intersecting the first wellbore.  
   
   
       33 . The method of  claim 32 , further comprising the step of guiding a cutting tool to form the second wellbore so that it intersects the first wellbore.  
   
   
       34 . The method of  claim 33 , wherein the cutting tool guiding step further comprises guiding the cutting tool toward at least one radioactive source on the first tubular string.  
   
   
       35 . The method of  claim 33 , wherein the cutting tool guiding step further comprises guiding the cutting tool toward a spaced apart array of radioactive sources on the first tubular string.  
   
   
       36 . The method of  claim 11 , wherein the guiding step further comprises displacing the second tubular string through a window.  
   
   
       37 . The method of  claim 36 , further comprising the step of forming the window in a sidewall of a third tubular string lining the second wellbore.  
   
   
       38 . The method of  claim 11 , wherein the expanding step further comprises applying a pressure differential across a wall of the entry guide.  
   
   
       39 . The method of  claim 11 , wherein the expanding step further comprises inflating a membrane within the entry guide.  
   
   
       40 . The method of  claim 39 , further comprising the step of conveying the membrane into the entry guide on a third tubular string, and wherein the inflating step further comprises applying pressure to an interior of the third tubular string.  
   
   
       41 . The method of  claim 11 , further comprising the step of sealingly engaging the first and second tubular strings with each other.  
   
   
       42 . The method of  claim 41 , wherein the sealingly engaging step further comprises attaching a seal on the first tubular string.  
   
   
       43 . The method of  claim 41 , wherein the sealingly engaging step further comprises attaching a seal on the second tubular string.  
   
   
       44 . The method of  claim 41 , wherein the sealingly engaging step further comprises expanding the second tubular string within the first tubular string.  
   
   
       45 . The method of  claim 41 , wherein the sealingly engaging step further comprises positioning a seal between the first and second tubular strings after the guiding step.  
   
   
       46 . The method of  claim 41 , wherein the sealingly engaging step further comprises swelling a sealing element between the first and second tubular strings.  
   
   
       47 . The method of  claim 41 , wherein the sealingly engaging step further comprises causing metal to metal contact between the first and second tubular strings.  
   
   
       48 . The method of  claim 11 , wherein the guiding step further comprises inserting a portion of the second tubular string into a portion of the first tubular string.  
   
   
       49 . The method of  claim 48 , further comprising the step of expanding the second tubular string portion within the first tubular string portion.  
   
   
       50 . The method of  claim 49 , wherein the second tubular string portion expanding step further comprises increasing an inner dimension of the second tubular string, thereby causing the second tubular string inner dimension to become equivalent to an inner dimension of the first tubular string.  
   
   
       51 . The method of  claim 49 , wherein the second tubular string portion expanding step further comprises increasing an inner dimension of the second tubular string, thereby causing the second tubular string inner dimension to become at least as large as an inner dimension of the first tubular string.  
   
   
       52 . The method of  claim 49 , wherein the second tubular string portion expanding step further comprises sealingly engaging the second tubular string portion with the first tubular string portion.  
   
   
       53 . The method of  claim 48 , wherein in the inserting step, the first tubular string portion is the entry guide.  
   
   
       54 . A well interconnection system, comprising: 
 first and second wellheads interconnected to each other by first and second tubular strings in sealed communication with each other at a first subterranean tubular string connection;    a first wellbore junction disposed between the first wellhead and the first tubular string connection; and    a second wellbore junction disposed between the second wellhead and the first tubular string connection.    
   
   
       55 . The system of  claim 54 , wherein the first tubular string includes a screen.  
   
   
       56 . The system of  claim 55 , wherein the screen is gravel packed.  
   
   
       57 . The system of  claim 55 , wherein the screen is expanded in the well.  
   
   
       58 . The system of  claim 55 , wherein the screen is positioned between the first wellbore junction and the first tubular string connection.  
   
   
       59 . The system of  claim 54 , wherein the first and second wellbore junctions are interconnected to each other by third and fourth tubular strings in sealed communication with each other at a second subterranean tubular string connection.  
   
   
       60 . The system of  claim 59 , wherein the third tubular string includes a screen.  
   
   
       61 . The system of  claim 60 , wherein the screen is gravel packed.  
   
   
       62 . The system of  claim 60 , wherein the screen is expanded in the well.  
   
   
       63 . The system of  claim 60 , wherein the screen is positioned between the first wellbore junction and the second tubular string connection.  
   
   
       64 . A method of connecting first and second tubular strings in a well, the method comprising the steps of: 
 providing an expandable entry guide on the first tubular string;    positioning the first tubular string in a first wellbore;    positioning the second tubular string in a second wellbore intersecting the first wellbore; and    guiding the second tubular string into the first tubular string via the entry guide.    
   
   
       65 . The method of  claim 64 , wherein the providing step further comprises providing an inclined surface on the entry guide, and wherein the guiding step further comprises using the inclined surface to guide the second tubular string into the first tubular string.  
   
   
       66 . The method of  claim 64 , wherein the guiding step further comprises releasing a protective sheath to thereby uncover a seal on the second tubular string.  
   
   
       67 . The method of  claim 66 , further comprising the step of sealingly engaging the seal within the first tubular string, thereby providing sealed communication between the first and second tubular strings.  
   
   
       68 . The method of  claim 66 , wherein the releasing step further comprises releasing the sheath from a latch carried on the second tubular string.  
   
   
       69 . The method of  claim 68 , further comprising the step of engaging the latch with a profile in the first tubular string, thereby securing the second tubular string to the first tubular string.  
   
   
       70 . The method of  claim 64 , further comprising the step of securing the second tubular string to the first tubular string.  
   
   
       71 . The method of  claim 70 , wherein the securing step further comprises engaging a profile formed within the first tubular string.  
   
   
       72 . The method of  claim 71 , wherein in the profile engaging step, the profile is formed within the entry guide.  
   
   
       73 . The method of  claim 70 , wherein the securing step further comprises expanding the second tubular string within the first tubular string.  
   
   
       74 . The method of  claim 70 , wherein the securing step further comprises engaging a latch on the second tubular string with the first tubular string.  
   
   
       75 . The method of  claim 70 , wherein the securing step further comprises engaging a latch with a profile.  
   
   
       76 . The method of  claim 64 , further comprising the step of cutting through an outer end wall of the entry guide.  
   
   
       77 . The method of  claim 76 , wherein the cutting step further comprises guiding a cutting tool using an inclined surface formed on the outer end wall.  
   
   
       78 . The method of  claim 76 , wherein the cutting step further comprises cutting inwardly through the outer end wall.  
   
   
       79 . The method of  claim 76 , wherein the cutting step further comprises cutting outwardly through the outer end wall.  
   
   
       80 . The method of  claim 76 , wherein the cutting step further comprises cutting through a check valve.  
   
   
       81 . The method of  claim 80 , further comprising the step of cementing the first tubular string in the well by flowing cement outwardly through the check valve prior to the cutting step.  
   
   
       82 . The method of  claim 76 , further comprising the step of guiding a cutting tool toward the outer end wall using at least one radioactive source attached to the first tubular string.  
   
   
       83 . The method of  claim 82 , wherein the cutting tool guiding step further comprises detecting a spaced apart series of the radioactive sources.  
   
   
       84 . The method of  claim 82 , wherein the cutting tool guiding step further comprises guiding the cutting tool through the second wellbore.  
   
   
       85 . The method of  claim 64 , further comprising the step of guiding a cutting tool to form the second wellbore so that it intersects the first wellbore.  
   
   
       86 . The method of  claim 85 , wherein the cutting tool guiding step further comprises guiding the cutting tool toward at least one radioactive source on the first tubular string.  
   
   
       87 . The method of  claim 85 , wherein the cutting tool guiding step further comprises guiding the cutting tool toward a spaced apart array of radioactive sources on the first tubular string.  
   
   
       88 . The method of  claim 64 , wherein the guiding step further comprises displacing the second tubular string through a window.  
   
   
       89 . The method of  claim 88 , further comprising the step of forming the window in a sidewall of a third tubular string lining the second wellbore.  
   
   
       90 . The method of  claim 64 , further comprising the step of expanding the entry guide by applying a pressure differential across a wall of the entry guide.  
   
   
       91 . The method of  claim 64 , further comprising the step of expanding the entry guide by inflating a membrane within the entry guide.  
   
   
       92 . The method of  claim 91 , further comprising the step of conveying the membrane into the entry guide on a third tubular string, and wherein the inflating step further comprises applying pressure to an interior of the third tubular string.  
   
   
       93 . The method of  claim 64 , further comprising the step of sealingly engaging the first and second tubular strings with each other.  
   
   
       94 . The method of  claim 93 , wherein the sealingly engaging step further comprises attaching a seal on the first tubular string.  
   
   
       95 . The method of  claim 93 , wherein the sealingly engaging step further comprises attaching a seal on the second tubular string.  
   
   
       96 . The method of  claim 93 , wherein the sealingly engaging step further comprises expanding the second tubular string within the first tubular string.  
   
   
       97 . The method of  claim 93 , wherein the sealingly engaging step further comprises positioning a seal between the first and second tubular strings after the guiding step.  
   
   
       98 . The method of  claim 93 , wherein the sealingly engaging step further comprises swelling a sealing element between the first and second tubular strings.  
   
   
       99 . The method of  claim 93 , wherein the sealingly engaging step further comprises causing metal to metal contact between the first and second tubular strings.  
   
   
       100 . The method of  claim 64 , wherein the guiding step further comprises inserting a portion of the second tubular string into a portion of the first tubular string.  
   
   
       101 . The method of  claim 100 , further comprising the step of expanding the second tubular string portion within the first tubular string portion.  
   
   
       102 . The method of  claim 101 , wherein the second tubular string portion expanding step further comprises increasing an inner dimension of the second tubular string, thereby causing the second tubular string inner dimension to become equivalent to an inner dimension of the first tubular string.  
   
   
       103 . The method of  claim 101 , wherein the second tubular string portion expanding step further comprises increasing an inner dimension of the second tubular string, thereby causing the second tubular string inner dimension to become at least as large as an inner dimension of the first tubular string.  
   
   
       104 . The method of  claim 101 , wherein the second tubular string portion expanding step further comprises sealingly engaging the second tubular string portion with the first tubular string portion.  
   
   
       105 . The method of  claim 100 , wherein in the inserting step, the first tubular string portion is the entry guide.  
   
   
       106 . A well interconnection system, comprising: 
 first, second and third wellheads interconnected to each other substantially underground.    
   
   
       107 . The system of  claim 106 , wherein the first and second wellheads are interconnected to each other by first and second tubular strings in sealed communication with each other at a first subterranean tubular string connection.  
   
   
       108 . The system of  claim 107 , wherein the second and third wellheads are interconnected to each other by third and fourth tubular strings in sealed communication with each other at a second subterranean tubular string connection.  
   
   
       109 . The system of  claim 106 , wherein the second wellhead comprises a pumping station for transferring fluid between the first and third wellheads.  
   
   
       110 . The system of  claim 106 , wherein the first and second wellheads are interconnected via first and second intersecting wellbores.  
   
   
       111 . The system of  claim 110 , wherein the second and third wellheads are interconnected via third and fourth intersecting wellbores.