CA2376584A1 - Circulating tubing head - Google Patents
Circulating tubing head Download PDFInfo
- Publication number
- CA2376584A1 CA2376584A1 CA002376584A CA2376584A CA2376584A1 CA 2376584 A1 CA2376584 A1 CA 2376584A1 CA 002376584 A CA002376584 A CA 002376584A CA 2376584 A CA2376584 A CA 2376584A CA 2376584 A1 CA2376584 A1 CA 2376584A1
- Authority
- CA
- Canada
- Prior art keywords
- dognut
- circulating
- housing
- sub
- tubing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000004519 manufacturing process Methods 0.000 claims abstract description 21
- 238000007789 sealing Methods 0.000 claims abstract description 10
- 239000012530 fluid Substances 0.000 claims description 7
- 238000000034 method Methods 0.000 claims 1
- 238000005086 pumping Methods 0.000 claims 1
- 239000004576 sand Substances 0.000 description 4
- 239000006260 foam Substances 0.000 description 3
- 238000012856 packing Methods 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000005187 foaming Methods 0.000 description 2
- 239000004519 grease Substances 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B33/00—Sealing or packing boreholes or wells
- E21B33/02—Surface sealing or packing
- E21B33/03—Well heads; Setting-up thereof
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/12—Methods or apparatus for controlling the flow of the obtained fluid to or in wells
- E21B43/121—Lifting well fluids
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Earth Drilling (AREA)
Abstract
A circulating tubing head for an artificial lift system which includes a housing having a first end, a second end and an interior surface defining an interior bore. A dognut is provided having a first end and a second end. The dognut being suspended within the interior bore toward the first end of the housing. A locking assembly is provided for securing the dognut within interior bore. A production sub is suspended from the second end of the dognut and extends past the second end of the housing. An annular sealing assembly forms a seal between production sub and the interior surface of the housing.
Description
TITLE OF THE INVENTION:
Circulating Tubing Head FIELD OF THE INVENTION
The present invention relates to a circulating tubing head BACKGROUND OF THE INVENTION
Typical wells fill up with sand deposits that are drawn into the wellbore. These deposits create a blockage into the inlet pump. Once this happens the well must be circulated to loosen up the blockage, force the sand back into formation or force the sand up to the surface through the annulus.
Wells are circulated at a high flow rate through the 1S tubing string using water or oil. Foam jobs may also be preformed to remove sand or stimulate the formation.
Circulating and foam jobs are currently being preformed by costly service rigs. A service rig will use a Blow Out Preventer (BOP) to control the well as they circulate through the tubing and also move the tubing up and down.
SU'L~tARY OF THE INVENTION
The present invention relates to a circulating tubing head having a sealing assembly, which will maintain control of the well without the need of a BOP while circulating.
According to this aspect of the invention there is provided a circulating tubing head for an artificial lift system which includes a housing having a first end, a second end and an interior surface defining an interior bore. A
dognut is provided having a first end and a second end. The dognut being suspended within the interior bore toward the first end of the housing. A locking assembly is provided for securing the dognut within interior bore. A production sub is suspended from the second end of the dognut and extends past the second end of the housing. An annular sealing assembly forms a seal between production sub and the interior surface of the housing.
The above described circulating tubing head (CTH) allows the well to be circulated while using a Flush-By Rig rather than a conventional service rig. The CTH is located between the casing bowl and flow tee assembly, and may be used with various tubing string sizes and all types of artificial down hole pumps. Utilizing the CTH is a more cost effective approach as it enables a Flush-By Rig to be used to perform circulating and foam jobs. Conventional methods do not allow a Flush-By unit to perform a circulation or foaming operation because there is no well control in place. The production sub is suspended within the CTH by means of a dognut. A seal is created around the production sub and also around the circulating sub during circulating operations. Fluid may be circulated down the tubing while the tubing is moved vertically or rotated in the wellbore without the use of a conventional Blow Out Preventer (BOP).
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to in any way limit the scope of the invention to the particular embodiment or embodiments shown, wherein:
FIGURE 1 is a is a longitudinal axial section through the invention including a typical wellhead configuration.
FIGURE 2 is a is a longitudinal axial section through the invention showing a detailed assembly.
FIGURE 3 is a is a longitudinal axial section through the invention showing the operation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment, a circulating Tubing Head (CTH), will now be described with reference to FIGURES 1 through 3.
Structure and Relationship of Parts:
Attention is first directed to Figure 1, which illustrates a typical artificial lift system. At the top, a flow tee with rod blow out preventer (3) is attached above the circulating tubing head (CTH) (1). Below CTH, is the casing bowl (2), which is attached to the production casing (7) . The production sub (5) is supported in the CTH by means of a dognut(12).
Attached to the production sub (5) is the production tubing string (8).
The polished rod (10) operates in the annular space of the CTH (1), flow tee (3), casing bowl (2), production sub (5) and production tubing (8). Surface equipment (4) support the polished rod (1 0) and the sucker rod (6), which are attached below.
Attached to the tubing (8) and/ or the rods (6), is the pump (9) which is operated by the rods (6).
Figure 2 illustrates the circulating tubing head in more detail. The spool housing (11) has an upper flange (13) and lower flange ( 14 ) , the bore is used to support the dognut ( 12 ) , and a lower annular space is used to house the seal assembly 2S (15). The top flange (13) of the spool housing (11) has lock nut assembly's (32) to lock dognut (12) into place. The upper flange (13) attaches to the bottom of the flow tee with rod blow out preventer (3), the bottom flange (14) of the spool housing (11) attaches to the top flange of the casing bowl (2) The dognut (12) has internal threads which are used to support the tubing string (8), and for removal. The dognut (12) has an external taper with o-ring seals (19) for sealing, the tapper is used to support string (8) weight and prevent rotation.
The seal assembly (15) consist of a lower bushing (16), lower pack seals (1 7), lattern ring (19), upper pack seals (18) and packing nut (20). Two lower seal ports (21) drilled radial at 180 degrees, intersect with seal cavity (23). Two upper seal ports (22) drilled radially at 180 degrees, intersect with thread relief (24). High pressure, sampling valve (25) are used to check the sealing integrity of the lower pack seals (15). High pressure, sampling valve (26) are used to check the sealing integrity of the upper pack seals (18).
Grease zerks (27) are used to grease and perform a pressure test on the lower pack seals (15) and upper pack seals (18).
Operation:
Figure 3 illustrates the functionality of the invention.
Remove surface equipment (4) and flow tee (3). Connect hydraulic pump to lower seal port (21) and charge to 100 PSI, ensure seals hold pressure. Remove polished rod (1 0) and hang rods (6) on top of production sub (5) using a rod hanger (28).
Attach pup joint to top of dognut (12), back off three lock nut assembly's (32), lift tubing string (8) up until two flats (30) on production sub (5) are visible above the circulating tubing head (1). Support tubing string (8) by using a slip that mates with the two flats (30) on production sub (5). Remove dognut (12) and attach circulating sub (29) to production sub (5).
Circulate fluid through the top of the circulating sub (29) and lower or raise tubing string (8) as required. If the well becomes uncontrollable or circulation medium fills the annulus, no fluid or gas is allowed to escape due to the seal assembly (15). Lower pack seals (17) seal around the inside circumference of the seal cavity (23 ) area of the spool housing (1 1) and around the outside of the production sub (5) and circulating sub (29) . The lower pack seals (17) and upper pack seals (18) resist fluid leakage as the well is circulated.
Addition seal pressure can be increased by rotating the packing nut (20) clock-wise. Rotating the packing nut (20) compresses the lower pack seals (17) and upper pack seals (18) creating a greater sealing force against the seal cavity (23), production sub (5) and circulating sub (29).
Well control is achieved by ensuring annular fluid escape is prevented through the sealing assembly in the circulating 5 head assembly. Tubing control is achieved by providing a certified valve (31) on top of the circulating sub (29).
Advantages:
Lower operating costs by;
l0 - flush-by units can be used because a blowout preventor is not needed, utilizing flush-by units at a lower hourly rates than service rigs;
- Well bore can be circulated thus improving production and down time;
- Foaming jobs can be performed with a cost saving due to flush-by units lower hourly rates;
- Tubing can be safely rotated thus reducing tubing wear.
In this patent document, the word "comprising" is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article "a" does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements.
It will be apparent to one skilled in the art that modifications may be made to the illustrated embodiment without departing from the spirit and scope of the invention as hereinafter defined in the Claims.
Circulating Tubing Head FIELD OF THE INVENTION
The present invention relates to a circulating tubing head BACKGROUND OF THE INVENTION
Typical wells fill up with sand deposits that are drawn into the wellbore. These deposits create a blockage into the inlet pump. Once this happens the well must be circulated to loosen up the blockage, force the sand back into formation or force the sand up to the surface through the annulus.
Wells are circulated at a high flow rate through the 1S tubing string using water or oil. Foam jobs may also be preformed to remove sand or stimulate the formation.
Circulating and foam jobs are currently being preformed by costly service rigs. A service rig will use a Blow Out Preventer (BOP) to control the well as they circulate through the tubing and also move the tubing up and down.
SU'L~tARY OF THE INVENTION
The present invention relates to a circulating tubing head having a sealing assembly, which will maintain control of the well without the need of a BOP while circulating.
According to this aspect of the invention there is provided a circulating tubing head for an artificial lift system which includes a housing having a first end, a second end and an interior surface defining an interior bore. A
dognut is provided having a first end and a second end. The dognut being suspended within the interior bore toward the first end of the housing. A locking assembly is provided for securing the dognut within interior bore. A production sub is suspended from the second end of the dognut and extends past the second end of the housing. An annular sealing assembly forms a seal between production sub and the interior surface of the housing.
The above described circulating tubing head (CTH) allows the well to be circulated while using a Flush-By Rig rather than a conventional service rig. The CTH is located between the casing bowl and flow tee assembly, and may be used with various tubing string sizes and all types of artificial down hole pumps. Utilizing the CTH is a more cost effective approach as it enables a Flush-By Rig to be used to perform circulating and foam jobs. Conventional methods do not allow a Flush-By unit to perform a circulation or foaming operation because there is no well control in place. The production sub is suspended within the CTH by means of a dognut. A seal is created around the production sub and also around the circulating sub during circulating operations. Fluid may be circulated down the tubing while the tubing is moved vertically or rotated in the wellbore without the use of a conventional Blow Out Preventer (BOP).
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to in any way limit the scope of the invention to the particular embodiment or embodiments shown, wherein:
FIGURE 1 is a is a longitudinal axial section through the invention including a typical wellhead configuration.
FIGURE 2 is a is a longitudinal axial section through the invention showing a detailed assembly.
FIGURE 3 is a is a longitudinal axial section through the invention showing the operation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment, a circulating Tubing Head (CTH), will now be described with reference to FIGURES 1 through 3.
Structure and Relationship of Parts:
Attention is first directed to Figure 1, which illustrates a typical artificial lift system. At the top, a flow tee with rod blow out preventer (3) is attached above the circulating tubing head (CTH) (1). Below CTH, is the casing bowl (2), which is attached to the production casing (7) . The production sub (5) is supported in the CTH by means of a dognut(12).
Attached to the production sub (5) is the production tubing string (8).
The polished rod (10) operates in the annular space of the CTH (1), flow tee (3), casing bowl (2), production sub (5) and production tubing (8). Surface equipment (4) support the polished rod (1 0) and the sucker rod (6), which are attached below.
Attached to the tubing (8) and/ or the rods (6), is the pump (9) which is operated by the rods (6).
Figure 2 illustrates the circulating tubing head in more detail. The spool housing (11) has an upper flange (13) and lower flange ( 14 ) , the bore is used to support the dognut ( 12 ) , and a lower annular space is used to house the seal assembly 2S (15). The top flange (13) of the spool housing (11) has lock nut assembly's (32) to lock dognut (12) into place. The upper flange (13) attaches to the bottom of the flow tee with rod blow out preventer (3), the bottom flange (14) of the spool housing (11) attaches to the top flange of the casing bowl (2) The dognut (12) has internal threads which are used to support the tubing string (8), and for removal. The dognut (12) has an external taper with o-ring seals (19) for sealing, the tapper is used to support string (8) weight and prevent rotation.
The seal assembly (15) consist of a lower bushing (16), lower pack seals (1 7), lattern ring (19), upper pack seals (18) and packing nut (20). Two lower seal ports (21) drilled radial at 180 degrees, intersect with seal cavity (23). Two upper seal ports (22) drilled radially at 180 degrees, intersect with thread relief (24). High pressure, sampling valve (25) are used to check the sealing integrity of the lower pack seals (15). High pressure, sampling valve (26) are used to check the sealing integrity of the upper pack seals (18).
Grease zerks (27) are used to grease and perform a pressure test on the lower pack seals (15) and upper pack seals (18).
Operation:
Figure 3 illustrates the functionality of the invention.
Remove surface equipment (4) and flow tee (3). Connect hydraulic pump to lower seal port (21) and charge to 100 PSI, ensure seals hold pressure. Remove polished rod (1 0) and hang rods (6) on top of production sub (5) using a rod hanger (28).
Attach pup joint to top of dognut (12), back off three lock nut assembly's (32), lift tubing string (8) up until two flats (30) on production sub (5) are visible above the circulating tubing head (1). Support tubing string (8) by using a slip that mates with the two flats (30) on production sub (5). Remove dognut (12) and attach circulating sub (29) to production sub (5).
Circulate fluid through the top of the circulating sub (29) and lower or raise tubing string (8) as required. If the well becomes uncontrollable or circulation medium fills the annulus, no fluid or gas is allowed to escape due to the seal assembly (15). Lower pack seals (17) seal around the inside circumference of the seal cavity (23 ) area of the spool housing (1 1) and around the outside of the production sub (5) and circulating sub (29) . The lower pack seals (17) and upper pack seals (18) resist fluid leakage as the well is circulated.
Addition seal pressure can be increased by rotating the packing nut (20) clock-wise. Rotating the packing nut (20) compresses the lower pack seals (17) and upper pack seals (18) creating a greater sealing force against the seal cavity (23), production sub (5) and circulating sub (29).
Well control is achieved by ensuring annular fluid escape is prevented through the sealing assembly in the circulating 5 head assembly. Tubing control is achieved by providing a certified valve (31) on top of the circulating sub (29).
Advantages:
Lower operating costs by;
l0 - flush-by units can be used because a blowout preventor is not needed, utilizing flush-by units at a lower hourly rates than service rigs;
- Well bore can be circulated thus improving production and down time;
- Foaming jobs can be performed with a cost saving due to flush-by units lower hourly rates;
- Tubing can be safely rotated thus reducing tubing wear.
In this patent document, the word "comprising" is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article "a" does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements.
It will be apparent to one skilled in the art that modifications may be made to the illustrated embodiment without departing from the spirit and scope of the invention as hereinafter defined in the Claims.
Claims (2)
1. A circulating tubing head for an artificial lift system, comprising:
a housing having a first end, a second end and an interior surface defining an interior bore;
a dognut having a first end and a second end, the dognut being positioned within the interior bore toward the first end of the housing;
a locking assembly securing the dognut within interior bore;
a production sub suspended from the second end of the dognut and extending past the second end of the housing; and an annular sealing assembly forming a seal between production sub and the interior surface of the housing.
a housing having a first end, a second end and an interior surface defining an interior bore;
a dognut having a first end and a second end, the dognut being positioned within the interior bore toward the first end of the housing;
a locking assembly securing the dognut within interior bore;
a production sub suspended from the second end of the dognut and extending past the second end of the housing; and an annular sealing assembly forming a seal between production sub and the interior surface of the housing.
2. A method of circulating fluid through a tubing head by means of which a tubing string and pumping rods extend into a well casing, comprising the steps of:
sealing annular space between tubing string and well casing;
removing all equipment positioned above the tubing head;
hanging rods within the tubing string using a rod hanger;
lifting up the tubing string using a lifting sub;
attaching a circulating sub to the tubing string; and circulating fluid through the circulating sub and down the tubing string.
sealing annular space between tubing string and well casing;
removing all equipment positioned above the tubing head;
hanging rods within the tubing string using a rod hanger;
lifting up the tubing string using a lifting sub;
attaching a circulating sub to the tubing string; and circulating fluid through the circulating sub and down the tubing string.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002376584A CA2376584A1 (en) | 2002-03-13 | 2002-03-13 | Circulating tubing head |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002376584A CA2376584A1 (en) | 2002-03-13 | 2002-03-13 | Circulating tubing head |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2376584A1 true CA2376584A1 (en) | 2003-09-13 |
Family
ID=27810571
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002376584A Abandoned CA2376584A1 (en) | 2002-03-13 | 2002-03-13 | Circulating tubing head |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2376584A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117365343A (en) * | 2023-11-03 | 2024-01-09 | 西安石油大学 | Setting anchor device and downhole choke having the same |
-
2002
- 2002-03-13 CA CA002376584A patent/CA2376584A1/en not_active Abandoned
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117365343A (en) * | 2023-11-03 | 2024-01-09 | 西安石油大学 | Setting anchor device and downhole choke having the same |
| CN117365343B (en) * | 2023-11-03 | 2024-04-23 | 西安石油大学 | Setting anchor device and downhole choke having the same |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |