SEALING THE TUBING HANGER

Background of the Invention

Field of the Invention

This invention relates to the field of wellbore equipment and more specifically to the field of tubing hangers.

Background of the Invention

Tubing hangers are conventionally located in the tubing head and attached to the topmost tubing joint in the wellhead. Typically, the tubing hanger supports the tubing string weight. The tubing hanger also seals the annulus from the upper wellhead and Christmas tree.

Tubing hangers have sealing systems and methods for testing seals. Such sealing systems include a variety of seals. Drawbacks to conventional sealing systems include the use of mud to kill the well, with the sealing system then typically being used. Killing the well with mud may be expensive and may also be dangerous to the wellbore. Further drawbacks include adding a frac valve to the top of the tubing hanger, with frac valves typically increasing costs. Additional drawbacks include inefficiencies in testing the sealing system. Drawbacks to conventional testing methods include inefficiencies and the expense involved in testing the tubing hanger.

Consequently, there is a need for improved tubing hangers and improved methods for testing and sealing tubing hangers.

BRIEF SUMMARY OF SOME OF THE PREFERRED EMBODIMENTS

These and other needs in the art are addressed in one embodiment by a tubing hanger assembly. The tubing hanger assembly includes a tubing hanger body having a mandrel receiving body section, a seal receptacle body section, a tubing receiving body section disposed on the opposing end of the tubing hanger body from the mandrel receiving body section, and wherein the seal receptacle body section is disposed between the mandrel receiving body section and the tubing receiving body section. The tubing hanger assembly also includes an interior bore extending longitudinally through the tubing hanger body. The interior bore includes a mandrel bore disposed within the mandrel receiving body section, a seal receptacle bore disposed within the seal receptacle body section, a valve preparation bore disposed within the tubing receiving body section, a tubing bore disposed within the tubing receiving body section, and wherein the valve preparation bore is disposed between the tubing bore and the seal receptacle bore. In addition, the tubing hanger assembly includes a test port. The test port extends through the seal receptacle body section to the seal receptacle bore. The mandrel receiving body section has an upper suspension attachment system. The tubing receiving body section has a tubing attachment system.

In another embodiment, these and other needs in the art are addressed by a method for testing and sealing a tubing hanger that includes attaching a test mandrel to the tubing hanger. The tubing hanger has an interior bore and a test port. The method also includes providing a test seal in the interior bore. The test seal is disposed above the test port. In addition, the method includes adding pressure to the interior bore through the test port. The method further includes monitoring the pressure. Moreover, the method includes removing the test mandrel from the tubing hanger and attaching a production mandrel to the tubing hanger. Additionally, the method includes providing a seal in the interior bore. The seal has an upper seal and a lower seal. The upper seal is disposed above the test port, and the lower seal is disposed below the test port.

The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other embodiments for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent embodiments do not depart from the spirit and scope of the invention as set forth in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings in which:

Figure 1 illustrates a side cross sectional view of an embodiment of a tubing hanger with a test port;

Figure 2 illustrates a side cross sectional view of an embodiment of a tubing hanger with a test port and test mandrel;

Figure 3 illustrates an embodiment of a test mandrel with a sealing system;

Figure 4 illustrates a side cross sectional view of an embodiment of a tubing hanger and a production mandrel; and

Figure 5 illustrates an embodiment of a production mandrel with an upper sealing system and a lower sealing system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Figure 1 illustrates an embodiment of a tubing hanger 5 having tubing hanger body 1 15 with interior bore 70. Tubing hanger body 1 15 includes mandrel receiving body section 75, seal receptacle body section 95, and tubing receiving body section 1 10. Interior bore 70 includes valve preparation bore 20, mandrel bore 60, tubing bore 65, and seal receptacle bore 100. Mandrel receiving body section 75 is configured to receive a mandrel in mandrel bore 60. Tubing receiving body section 1 10 is configured to receive tubing in tubing bore 65.

As shown in Figure 1, an embodiment of tubing hanger 5 includes mandrel receiving body section 75 having upper suspension attachment system 10. Upper suspension attachment system 10 is disposed on the interior surface of mandrel receiving body section 75. Upper suspension attachment system 10 includes any means suitable for connection of a mandrel to mandrel receiving body section 75. In embodiments, upper suspension attachment system 10 includes upper suspension threads or a notch mechanism. In an embodiment, upper suspension attachment system 10 includes upper suspension threads. It is to be understood that upper suspension threads refer to helical or spiral ridges. In an embodiment, the upper suspension threads are left-handed threads. It is to be understood that left-handed threads refer to threads that connect to a mandrel when the mandrel is rotated in an anti-clockwise direction to connect the mandrel (i.e., rotate the mandrel to screw the mandrel into mandrel bore 60), and that allow the mandrel to be removed when the mandrel is rotated in a clockwise direction (i.e., rotate the mandrel to screw the mandrel out of mandrel bore 60). Without limitation, the left-handed threads allow rotation of test mandrel 30 (or production mandrel 80) to remove test mandrel 30 (or production mandrel 80) from tubing hanger 5 without such motion removing any unwanted threads (i.e., when rotation becomes stuck). In other embodiments, upper suspension attachment system 10 is a notch mechanism. The notch mechanism includes a notch disposed in the interior surface of mandrel receiving body section 75. The notch may have any sufficient configuration to allow a latch on the mandrel to be disposed in the notch. In embodiments as shown, mandrel receiving body section 75 also includes mandrel stop 120. Mandrel stop 120 includes any suitable means by which further movement of a mandrel into interior bore 70 is stopped. In an embodiment, mandrel stop 120 is a portion of mandrel receiving body section 75 that extends outward from the interior surface of mandrel receiving body section 75. In some embodiments, mandrel stop 120 extends outward at about a 90 degree angle from the interior surface. In embodiments as shown, mandrel stop 120 is disposed on the end of mandrel bore 60 proximate seal receptacle bore 100.

As further shown in Figure 1 , an embodiment of tubing hanger 5 includes seal receptacle body section 95 having test port 15 and seal receptacle bore 100. Seal receptacle bore 100 is configured to receive a portion of a mandrel (i.e., such as a portion having seals). In embodiments, seal receptacle bore 100 has a smaller inside diameter than mandrel bore 60. In an embodiment as shown in Figure 1, seal receptacle bore 100 has about the same inside diameter as the inside diameter of the portion of interior bore 70 between mandrel stop 120. Test port 15 is an opening through seal receptacle bore section 95. Test port 15 extends from the outer surface of seal receptacle body section 95 to the interior surface of seal receptacle body section 95, which provides an opening from outside of tubing hanger body 115 into seal receptacle bore 100. Test port 15 may extend through seal receptacle body section 95 at any suitable angle for facilitating testing purposes. In embodiments, test port 15 extends through seal receptacle body section 95 about perpendicular to tubing hanger body 115. Test port 15 is of a sufficient diameter to allow pressure to be added to seal receptacle bore 100. In embodiments as shown, seal receptacle body section 95 also includes seal receptacle stop 125. Seal receptacle stop 125 includes any suitable means by which further movement of a mandrel into interior bore 70 is stopped. Seal receptacle stop 125 is on the opposing end of seal receptacle bore 100 from the end of seal receptacle bore 100 that is proximate mandrel stop 120. In an embodiment, seal receptacle stop 125 is a portion of seal receptacle body section 95 that extends outward from the interior surface of seal receptacle body section 95. In some embodiments, seal receptacle stop 125 extends outward at about a 90 degree angle from the interior surface.

In embodiments as shown in Figure 1, tubing hanger 5 includes tubing receiving body section 110 having valve preparation bore 20 and tubing bore 65. Valve preparation bore 20 is configured to receive valves such as back pressure valves. Any suitable back pressure valves may be used. For instance, without limitation, examples of suitable valves include H-type back pressure valves and L-type back pressure valves. In an embodiment, an H-type back pressure valve and/or a L-type back pressure valve are disposed in valve preparation bore 20. Without limitation, the back pressure valves prevent pressure (i.e., back pressure) from moving up tubing hanger 5 (i.e., in the direction in tubing hanger 5 distal to tubing bore 65). In embodiments, valve preparation bore 20 has a smaller inside diameter than seal receptacle bore 100. In an embodiment as shown in Figure 1, valve preparation bore 20 has about the same inside diameter as the inside diameter of the portion of interior bore 70 between seal receptacle stop 125. In embodiments as shown, tubing receiving body section 110 also includes tubing stop 130. Tubing stop 130 includes any suitable means by which further movement of a tubing into interior bore 70 is stopped. Tubing stop 130 is on the opposing end of valve preparation bore 20 from the end of valve preparation bore 20 that is proximate seal receptacle stop 125. In an embodiment, tubing stop 130 is a portion of tubing receiving body section 110 that extends outward from the interior surface of tubing receiving body section 110. In some embodiments, tubing stop 130 extends outward at about a 90 degree angle from the interior surface. As further shown in Figure 1, an embodiment of tubing hanger 5 includes tubing receiving body section 110 having tubing attachment system 25. Tubing attachment system 25 is disposed on the interior surface of the portion of tubing receiving body section 110 in which tubing bore 65 is disposed. Tubing attachment system 25 includes any means suitable for connection of a tubing to tubing receiving body section 1 10. In embodiments, tubing attachment system 25 is threads or a notch mechanism. In an embodiment, tubing attachment system 25 is threads. It is to be understood that threads refer to helical or spiral ridges. The threads allow the tubing to be screwed into tubing bore 65 when the tubing and/or tubing hanger 5 are rotated. In embodiments, the threads for tubing attachment system 25 are right- handed threads. In other embodiments, tubing attachment system 25 is a tubing notch mechanism. The tubing notch mechanism includes a notch disposed in the interior surface of tubing receiving body section 110. The notch may have any sufficient configuration to allow a latch on the tubing to be disposed in the notch.

Figure 2 illustrates an embodiment of tubing hanger 5 in which a test mandrel 30 is attached to tubing hanger body 115. In the embodiment illustrated, test mandrel 30 is disposed in mandrel bore 60 and in a portion of seal receptacle bore 100. As shown in the embodiments of figures 2 and 3, test mandrel 30 includes upper test mandrel portion 135 and test mandrel seal portion 140. In embodiments as shown, upper test mandrel portion 135 has a diameter greater than the diameter of test mandrel seal portion 140. When test mandrel 30 is attached to tubing hanger body 115, upper test mandrel portion 135 is disposed in mandrel bore 60. Upper test mandrel portion 135 has suspension attachment system 40. Suspension attachment system 40 includes any means suitable for connection of test mandrel 30 to mandrel receiving body section 75. In embodiments, suspension attachment system 40 includes threads or a latch (or alternatively latches). It is to be understood that suspension attachment system 40 includes threads in embodiments in which upper suspension attachment system 10 is upper suspension threads, and suspension attachment system 40 includes a latch in embodiments in which upper suspension attachment system 10 is a notch mechanism. In an embodiment, suspension attachment system 40 includes threads. The threads sufficiently match the upper suspension threads to allow rotation of test mandrel 30 and/or tubing hanger body 115 to attach test mandrel 30 to tubing hanger 5. In an embodiment, the threads are left-handed threads. It is to be understood that the left-handed threads (i.e., regarding the threads) refer to threads that connect to tubing hanger body 115 when the test mandrel 30 is rotated in an anti-clockwise direction to connect the test mandrel 30 (i.e., rotate test mandrel 30 to screw test mandrel 30 into mandrel bore 60), and that allow test mandrel 30 to be removed from mandrel bore 60 when test mandrel 30 is rotated in a clockwise direction. In other embodiments, suspension attachment system 40 is a latch. The latch is suitably configured to be disposed in a notch on the interior surface of mandrel receiving body section 75. Test mandrel seal portion 140 has sealing system 45. Sealing system 45 is disposed above test port 15. Sealing system 45 includes any suitable system for sealing mandrel bore 60 from the pressure provided through test port 15 to seal receptacle bore 100. In an embodiment, sealing system 45 includes any suitable type of elastomeric seal for sealing mandrel bore 60 from the pressure provided through test port 15 to seal receptacle bore 100. Without limitation, examples of suitable elastomeric seals include o-ring seals, dovetail seals, or any combinations thereof. In an embodiment, the elastomeric seal is a dovetail seal. Sealing system 45 may include any suitable number of seals to seal mandrel bore 60 from the pressure provided through test port 15 to seal receptacle bore 100. In an embodiment, sealing system 45 has two elastomeric seals, test mandrel seal 35 and test mandrel seal 35'. Without limitation, test mandrel seal 35' provides the seal and holds the pressure, with test mandrel seal 35 providing a back-up seal in case test mandrel seal 35' fails. For instance, in an embodiment as shown in figures 2 and 3, sealing system 45 includes two elastomeric dovetail seals, test mandrel seal 35 and test mandrel seal 35'. In alternative embodiments (not illustrated), sealing system 45 has one elastomeric seal. As further shown in figures 2 and 3, test mandrel 30 has test mandrel shoulder 145. Test mandrel shoulder 145 is disposed at about where the diameter of test mandrel 30 is reduced from upper test mandrel portion 135 to the reduced diameter of test mandrel seal portion 140. Test mandrel shoulder 145 has a sufficient diameter and configuration to prevent further movement of test mandrel 30 into interior bore 70 when test mandrel shoulder 145 contacts mandrel stop 120. Test mandrel shoulder 145 may have any sufficient configuration to contact mandrel stop 120 and prevent the further movement of test mandrel 30 into interior bore 70. In embodiments, test mandrel shoulder 145 is about perpendicular to the exterior of upper test mandrel portion 135 and the exterior of test mandrel seal portion 140. In addition, as shown in figure 2, test mandrel 30 has test mandrel internal threads 165. Test mandrel internal threads 165 facilitate attachment of test mandrel 30 to well equipment such as tubing of the wellhead. Test mandrel internal threads 165 are right-handed threads. It is to be understood that right-handed threads refer to threads that connect to a well equipment (i.e., tubing) when the test mandrel 30 is rotated in a clockwise direction to connect the test mandrel 30 (i.e., rotate the test mandrel 30 to screw the test mandrel 30 into the tubing), and that allow the test mandrel 30 to be removed from the tubing when the test mandrel 30 is rotated in an anti-clockwise direction. Figure 4 illustrates an embodiment of tubing hanger 5 in which a production mandrel 80 is attached to tubing hanger body 115. In the embodiment illustrated, production mandrel 80 is disposed in mandrel bore 60 and in a portion of seal receptacle bore 100. As shown in the embodiments of figures 4 and 5, production mandrel 80 includes upper production mandrel portion 150 and production mandrel seal portion 155. In embodiments as shown, upper production mandrel portion 150 has a diameter greater than the diameter of production mandrel seal portion 155. When production mandrel 80 is attached to tubing hanger body 115, upper production mandrel portion 150 is disposed in mandrel bore 60. Upper production mandrel portion 150 has production mandrel attachment system 170. Production mandrel attachment system 170 includes any means suitable for connection of production mandrel 80 to mandrel receiving body section 75. In embodiments, production mandrel attachment system 170 is threads or a latch (or alternatively latches). It is to be understood that production mandrel attachment system 170 includes threads in embodiments in which upper suspension attachment system 10 is upper suspension threads, and production mandrel attachment system 170 includes a latch in embodiments in which upper suspension attachment system 10 is a notch mechanism. In an embodiment, production mandrel attachment system 170 includes threads. The threads sufficiently match the upper suspension threads to allow rotation of production mandrel 80 and/or tubing hanger 5 to attach production mandrel 80 to tubing hanger 5. In an embodiment, the threads are left-handed threads. Without limitation, the left-handed threads allow rotation of production mandrel 80 to remove production mandrel 80 from tubing hanger 5 without such motion removing any unwanted threads (i.e., rotation becomes stuck). In other embodiments, production mandrel attachment system 170 is a latch. The latch is suitably configured to be disposed in a notch on the interior surface of mandrel receiving body section 75. Production mandrel seal portion 155 has production mandrel sealing system 175. Production mandrel sealing system 175 includes any suitable system for sealing mandrel bore 60 and seal receptacle bore 100. In an embodiment, production mandrel sealing system 175 includes any suitable type of elastomeric seal for such sealing. Without limitation, examples of suitable elastomeric seals include o-ring seals, dovetail seals, or any combinations thereof. In an embodiment, the elastomeric seal is a dovetail seal. Such seals may be above and/or below test port 15. Production mandrel sealing system 175 may include any suitable number of seals for sealing. In an embodiment, production mandrel sealing system 175 has an upper sealing system 50 and a lower sealing system 55. In the embodiment illustrated, upper sealing system 50 is disposed above test port 15, and lower sealing system 55 is disposed below test port 15. Without limitation, lower sealing system 55 is disposed below test port 15 to prevent wellbore fluids from flowing out through test port 15. Upper sealing system 50 and lower sealing system 55 may have any suitable number of seals. In an embodiment, upper sealing system 50 has upper seals 85, 85', and lower sealing system 55 has lower seals 105, 105'. For instance, in an embodiment as shown in figures 4 and 5, upper sealing system 50 includes two elastomeric dovetail seals (upper seal 85 and upper seal 85'), and lower sealing system 55 includes two elastomeric dovetail seals (lower seal 105 and lower seal 105'). In alternative embodiments (not illustrated), upper sealing system 50 has one elastomeric seal, and/or lower sealing system 55 has one elastomeric seal. As further shown in figures 4 and 5, production mandrel 80 has production mandrel shoulder 160. Production mandrel shoulder 160 is disposed at about where the diameter of production mandrel 80 is reduced from upper production mandrel portion 150 to the reduced diameter of production mandrel seal portion 155. Production mandrel shoulder 160 has a sufficient diameter and configuration to prevent further movement of production mandrel 80 into interior bore 70 when production mandrel shoulder 160 contacts mandrel stop 120. Production mandrel shoulder 160 may have any sufficient configuration to contact mandrel stop 120 and prevent the further movement of production mandrel 80 into interior bore 70. In embodiments, production mandrel shoulder 160 is about perpendicular to the exterior of upper production mandrel portion 150 and the exterior of production mandrel seal portion 155. Moreover, as shown in figures 4 and 5, production mandrel 80 has production mandrel seal shoulder 180. Production mandrel seal shoulder 180 is disposed at the end of production mandrel seal portion 155 distal from production mandrel shoulder 160. Production mandrel seal shoulder 180 has a sufficient diameter and configuration to prevent further movement of production mandrel 80 into interior bore 70 when production mandrel seal shoulder 180 contacts seal receptacle stop 125. Production mandrel seal shoulder 180 may have any sufficient configuration to contact seal receptacle stop 125 and prevent the further movement of production mandrel 80 into interior bore 70. In embodiments, production mandrel seal shoulder 180 is about perpendicular to a longitudinal plane of production mandrel seal portion 155. In addition, as shown in figure 4, production mandrel 80 has production mandrel internal threads 90. Production mandrel internal threads 90 facilitate attachment of production mandrel 80 to well equipment such as tubing of the wellhead. Production mandrel internal threads 90 are right-handed threads. It is to be understood that right-handed threads for production mandrel 80 refer to threads that connect to well equipment (i.e., tubing) when production mandrel 80 is rotated in a clockwise direction to connect production mandrel 80 (i.e., rotate production mandrel 80 to screw the production mandrel 80 into the tubing), and that allow the production mandrel 80 to be removed from the tubing when the production mandrel 80 is rotated in an anti-clockwise direction. In an embodiment of operation of the embodiments of tubing hanger 5 shown in Figures 1, 2, and 4, test mandrel 30 is inserted into interior bore 70 and attached to tubing hanger 5. In such embodiments, tubing hanger 5 may be disposed in a wellbore and attached to a tubing (i.e., the tubing is attached by tubing attachment system 25). In an embodiment in which suspension attachment system 40 is threads, test mandrel 30 is screwed into mandrel bore 60 in an anti-clockwise direction (i.e., left-hand direction) until test mandrel shoulder 145 contacts mandrel stop 120. When test mandrel shoulder 145 contacts mandrel stop 120, in an embodiment in which sealing system 45 has test mandrel seals 35, 35', test mandrel seals 35, 35' are energized. Pressure is then added to seal receptacle bore 100 through test port 15. The pressure may be added by any suitable method. In an embodiment, the pressure is added by a pump. Any suitable method may be used to determine whether the pressure is being held by the seal. In an embodiment, the method may include adding pressure with a pump until a desired pressure is achieved. When the desired pressure is achieved, the pumped is stopped, and the pressure in interior bore 70 is monitored to determine if the pressure decreases. Without limitation, a monitored decrease in pressure may indicate that tubing hanger 5 is not a closed system, and tubing hanger 5 has a pressure leak. If there is no monitored decrease in pressure, tubing hanger 5 is a closed system with no pressure leaks. The pressure may be monitored by any suitable method. In an embodiment, a sensor or sensors on the pump monitor the pressure. In an embodiment, the sensor is a pressure gauge. In an embodiment in which the monitoring indicates that tubing hanger 5 is not a closed system, tubing hanger 5 may be checked to determine the source of the leak. In an embodiment in which the monitoring indicates that tubing hanger 5 is a closed system, test mandrel 30 is removed from tubing hanger 5. For instance, in an embodiment in which suspension attachment system 40 of test mandrel 30 is threads and test mandrel 30 was screwed into tubing hanger 5, test mandrel 30 is unscrewed to be removed from tubing hanger 5.

After test mandrel 30 is removed from tubing hanger 5, embodiments include attaching production mandrel 80 to tubing hanger 5. For instance, in an embodiment in which production mandrel attachment system 170 is threads, production mandrel 80 is screwed into mandrel bore 60 in an anti-clockwise direction (i.e., left-handed direction) until production mandrel shoulder 160 contacts mandrel stop 120 and/or production mandrel seal shoulder 180 contacts seal receptacle stop 125. When production mandrel shoulder 160 contacts mandrel stop 120 and/or production mandrel seal shoulder 180 contacts seal receptacle stop 125, in an embodiment in which production mandrel sealing system 175 has upper sealing system 50 (i.e., upper seals 85, 85') and lower sealing system 55 (i.e., lower seals 105, 105'), upper seals 85, 85' and lower seals 105, 105' are energized. In some embodiments, tubing hanger 5 may be pressure tested again. This pressure test may be accomplished in the same manner as the pressure test of tubing hanger 5 with attached test mandrel 30 or may use any other suitable method. For instance, in an embodiment, a portion of a joint of tubing is disposed outside of interior bore 70. The pressure is tested around the portion of the joint by applying pressure to the portion of the joint. If no pressure is leaked, production mandrel sealing system 175 is sufficiently energized. In embodiments, for production to commence, the back pressure valves in valve preparation bore 20 are removed. Without limitation, removing the back pressure valves facilitates production through interior bore 70.

Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations may be made herein without departing from the spirit and scope of the invention as defined by the appended claims.