Internal Blowout Preventer Apparatus

Abstract

An internal blowout preventer assembly having a central through-bore and flapper valve. The flapper valve permits fluid flow in a downward direction, but not the opposite (upward) direction. A retrievable tubular lockout sleeve can be conveyed via wireline, coiled tubing or other similar means and installed within the through-bore of the internal blowout preventer assembly. Once installed, the lockout sleeve prevents the flapper valve from closing, thereby permitting wireline or other concentric operations to be performed (as well as upward fluid flow) though the internal blowout preventer.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention pertains to an internal blowout preventer.

2. Brief Description of the Prior Art

Drilling rigs used for the drilling of oil and gas wells typically include a supportive rig floor positioned over a well, a derrick extending vertically above said rig floor, and lifting means which can be raised and lowered within said derrick. During drilling and completion operations, work is typically performed in a well using drill pipe or other tubular work string that is installed in a number of sections of roughly equal length called “joints”. As such, a typical drill string comprises a plurality of sections or joints of pipe, each of which has an internal, longitudinally extending bore. When a greater length of pipe is required, additional joints of pipe must be added to the string at the surface. Conversely, when a shorter length of pipe is desired, joints of pipe are removed from the string at the surface.

During drilling operations, a fluid known as drilling mud or drilling fluid is normally pumped down the longitudinally extending bore of the tubular drill pipe, and circulated up the annular space which is formed between the external surface of said drill pipe and the internal surface of the wellbore. Functions of such drilling mud include, without limitation, the following: (1) cooling and lubricating downhole equipment during drilling operations; (2) transportation of pieces of drilled-up rock and other debris from the bottom of the hole to the surface; and (3) providing hydrostatic pressure to control encountered subsurface pressures.

When a well is drilled to a desired depth, large diameter pipe is typically installed in said well and cemented in place. The casing provides structural support for the wellbore, while the cement protects and seals the wellbore and isolates downhole formations from each other. Cementing is typically performed by pumping cement slurry down the central bore of the casing, thereby displacing drilling fluids present within said casing. The cement slurry flows to the bottom of the wellbore, out the distal (bottom) end of the casing, and into the annular space existing between the outside of the casing and the inner surface of the wellbore. After the cement hardens, it forms a fluid seal and permanently positions the casing in place.

In many cases, it is desirable to set cement plugs at one or more depth(s) within a well bore. This process, commonly referred to as “spotting cement”, typically involves a pumping a predetermined volume of cement slurry down an open-ended length of drill pipe or work string. The cement is displaced with a predetermined volume of drilling fluids, such that the cement exits the bottom or distal end of the drill pipe or work string and forms a plug within the well bore.

Internal blow-out preventers (“IBOPs”) have been known in the art for many years. Such IBOPs generally function like check valves, in that the IBOP's permit fluid flow in one direction, but not in the opposing direction. Although IBOPs can be used in many different applications, IBOPs are frequently used during drilling operations and, more specifically, during spotting of downhole cement plugs or other heavy fluids within a well bore. During such operations, the IBOPs generally permit cement slurry and/or other heavy fluids to be pumped down drill pipe or work string, but prevent fluid flow into said drill pipe or work string in the opposing direction (whether due to feed in from a down hole formation, or the U-tube fluid effect).

For example, at least one IBOP is often placed within a tubular work string at desired depth(s) during such cementing operations. Heavy cement slurry and other fluids can be pumped down the internal bore of the work string through the IBOP(s) and out the bottom or distal end of the work string; however, because flow is not permitted in the opposite direction, the IBOP's prevent the cement slurry (which is typically heavier than other drilling fluids being used) from flowing back into the workstring.

Unfortunately, existing IBOPs suffer from some significant limitations. Notably, prior art IBOPs typically include restrictions through their central bore. As a result, it is generally not possible to conduct wireline, coiled tubing or other similar operations through said IBOPs. Thus, it is desirable to have an IBOP that has little or no restriction through its central bore, such that the IBOP will permit the passage of tools conveyed via wireline, coiled tubing or other means to be performed through such IBOP.

SUMMARY OF THE INVENTION

The present invention comprises an internal blowout preventer (IBOP) having a body defining a longitudinal central bore extending through said body. The IBOP of the present invention permits single-direction fluid flow (typically downward) through said central bore. However, a hinged flapper connected to the body of said IBOP prevents upward fluid flow (that is, in the opposite direction) through said central bore. Due to the configuration of the valve assembly of IBOP, and the substantially unobstructed central bore when said flapper is in the open position, it is possible to conduct wireline, coiled tubing or other similar operations through said IBOP assembly.

When use of wireline, coiled tubing or the like is desired, said flapper can be locked into the open position using a sliding-sleeve, lock-out device or other similar apparatus. In this manner, said flapper will not impede operations being conducted through the central bore of said IBOP, especially when such wireline and any connected tools are pulled upward through said bore.

In an alternative embodiment of the present invention, said flapper can comprise at least two opposing members that cooperate to block or restrict fluid flow through said central bore. Further, the body of said IBOP may also include an optional recess for receiving said flapper when in the open position, thereby reducing protrusion of said flapper into said central bore.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description of the preferred embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, the drawings show certain preferred embodiments. It is understood, however, that the invention is not limited to the specific methods and devices disclosed. Further, dimensions, materials and part names are provided for illustration purposes only and not limitation.

FIG. 1 depicts a partially exploded side sectional view of the IBOP assembly of the present invention.

FIG. 2 depicts a partially exploded side sectional view of the IBOP assembly of the present invention rotated 180 degrees from the depiction in FIG. 1.

FIG. 3 depicts a side view of the IBOP assembly of the present invention.

FIG. 4 depicts a side sectional view of the IBOP assembly of the present invention along line 4-4 of FIG. 3.

FIG. 5 depicts a perspective view of an upper body member of the IBOP of the present invention.

FIG. 6 depicts a side view of an upper body member of the IBOP of the present invention.

FIG. 7 depicts a side sectional view of an upper body member IBOP of the present invention along line 7-7 of FIG. 6.

FIG. 8 depicts a side view of a lower body member of the IBOP assembly of the present invention.

FIG. 9 depicts a side sectional view of a lower body member the IBOP assembly of the present invention along line 9-9 of FIG. 8.

FIG. 10 depicts a perspective view of a lockout sleeve of the IBOP assembly of the present invention.

FIG. 11 depicts a side view of a lockout sleeve of the IBOP assembly of the present invention.

FIG. 12 depicts a side sectional view of the IBOP assembly of the present invention along line 12-12 of FIG. 11.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

FIG. 1 depicts a partially exploded side sectional view of IBOP 10 of the present invention. In the preferred embodiment, said IBOP 10 of the present invention comprises mating upper body member 30 and lower body member 20. Upper body member 30 has upper connection member 31; although other connection means can be used, in the preferred embodiment said upper connection member 31 comprises a threaded female connector adapted for connection to a mating male threaded connector of drill pipe or other tubular work string. Through bore 32 extends through said upper body member 30. Clevis bracket members 33 extend from end 34 of upper body member 30.

Lower body member 20 has lower connection member 21; although other connection means can be used, in the preferred embodiment said lower connection member 21 comprises a threaded male connector adapted for connection to a mating female threaded connector of drill pipe or other tubular work string. Through bore 22 extends through said lower body member 20.

IBOP assembly 10 further comprises a flapper assembly comprising flapper 40 having clevis bracket members 43, flapper pivot pin 41 and bias spring 42. In the preferred embodiment, clevis bracket members 33 of upper body member 30 are received between clevis bracket members 43 of flapper 40. Each of said clevis bracket members 33 and 43 have aligned bores for receiving flapper pivot pin 41. In this configuration, flapper member 40 can pivot or rotate about said pivot pin 41. Bias spring 42 biases said flapper in a closed position (that is, closing through bore 32) as described in detail below.

Still referring to FIG. 1 tubular lockout sleeve 50 has body member 51 defining central through bore 52. In the preferred embodiment, the outer diameter of body member 51 of tubular lockout sleeve 50 is smaller than the diameter of through bore 32 of upper body member 30, such that said body member 51 can be received within said through bore 32. Said tubular lockout sleeve further comprises upper collar member 53.

FIG. 2 depicts a partially exploded side sectional view of IBOP 10 of the present invention rotated 180 degrees from the depiction in FIG. 1. As noted in FIG. 1, IBOP 10 of the present invention comprises mating upper body member 30 and lower body member 20. Upper body member 30 has upper connection member 31. Through bore 32 extends through said upper body member 30. Similarly, lower body member 20 has lower connection member 21, and through bore 22 extends through said lower body member 20.

Flapper member 40 is mounted using clevis bracket members 43 and pivot pin 41, and can pivot or rotate about the longitudinal axis of said pivot pin 41. In the preferred embodiment, said flapper member 40 can rotate about an angle of approximately 90 degrees. In the open position, as depicted in FIG. 2, said flapper member 40 is disposed against the recessed inner wall of flapper housing 23 defined by lower body member 20. In this position, said flapper 40 does not extend into or otherwise restrict through bores 32 or 22.

Although not shown in FIG. 2, bias spring 42 biases said flapper member 40 in a closed position during use of IBOP assembly 10. In such closed position, said flapper member 40 is rotated approximately 90 degrees, such that a portion of said flapper 40 seats against end 34 of upper member 30. In the preferred embodiment, when in the closed position, said flapper member 40 forms a fluid pressure seal against end 34, and prevents fluid from entering bore 32 of upper member 30 from below (that is, from bore 22 of lower body member 20), If desired, end 34 and/or sealing surface 44 of flapper member 40 can be recessed or otherwise shaped to engage with one another in order to facilitate a fluid pressure seal in a manner well known to those having skill in the art.

Tubular lockout sleeve 50 has body member 51 defining central through bore 52. The outer diameter of body member 51 of tubular lockout sleeve 50 is smaller than the diameter of through bore 32 of upper body member 30, such that said body member 51 can be received within said through bore 32. Said tubular lockout sleeve further comprises upper collar member 53.

Still referring to FIG. 2, transverse bore 36 is disposed through upper body member 30 and extends from the outer surface of said upper body member 30 to through bore 32. In the preferred embodiment, said transverse bore 36 is oriented substantially perpendicular to the longitudinal axis of through bore 32. Retention pin 60 and spring 61 are disposed within said transverse bore 36 and secured in place using cap 62. Spring 61 biases said retention pin 60 inward in the direction of bore 32 of upper body member 30.

Upper body member 30 has at least one recessed slot 35, while lower body member 20 has at least one recessed slot 25. When said upper body member 30 is mated with lower body member 20, said recessed slots 25 and 35 are aligned. Locking clip 70 is received within said aligned slots 25 and 35, and secured in place using locking clip pin 71.

FIG. 5 depicts a perspective view of upper body member 30 of IBOP assembly 10 of the present invention, while FIG. 6 depicts a side view of said upper body member 30 of IBOP assembly 10 of the present invention. Said upper body member 30 comprises substantially cylindrical body section 38, threads 37 and through bore 32. Clevis bracket members 33, each having aligned bores 33a, are disposed on end 34 of upper body member 30. Recessed slots 35 are formed in body section 38.

FIG. 7 depicts a side sectional view of upper body member 30 of IBOP assembly 10 of the present invention along line 7-7 of FIG. 6. Said upper body member 30 comprises substantially cylindrical body section 38, threads 37 and through bore 32. Clevis bracket members 37 are disposed on end 34 of upper body member 30. Recessed slots 35 are formed in body section 38 of upper body member 30.

FIG. 8 depicts a side view of a lower body member 20 of IBOP assembly 10 of the present invention, while FIG. 9 depicts a side sectional view of said lower body member 20 of IBOP assembly 10 of the present invention along line 9-9 of FIG. 8. Said lower body member 20 comprises substantially cylindrical body section 28, internal threads 27 and through bore 22. Recessed slots 25 are formed in body section 28.

Threads 37 of upper body member 30 engage with threads 27 of lower body member 20 in order to threadedly connect said upper and lower body members together. When said upper body member 30 is mated with lower body member 20, said recessed slots 25 and 35 are aligned. As described above, locking clip 70 is received within said aligned slots 25 and 35, and secured in place using locking clip pin 70 (which can be threaded or otherwise fasten locking clip 70 in place), to prevent said upper body member 30 and lower body member 20 from rotating (unscrewing) relative to each other.

FIG. 10 depicts a perspective view of lockout sleeve 50 of IBOP assembly 10 of the present invention. Tubular lockout sleeve 50 has body member 51 defining central through bore 52, as well as upper collar member 53. Optional tapered surface 54 can be disposed at the opposite end of lockout sleeve 50 from said upper collar member 53. Circumferential groove 55 forms a slot or recess that extends around the circumference of said body member 51; in the preferred embodiment, said circumferential groove 55 is oriented substantially perpendicular to the longitudinal axis of central bore 52.

FIG. 11 depicts a side view of lockout sleeve 50 of the present invention, while FIG. 12 depicts a side sectional view of lockout sleeve 50 of the present invention along line 12-12 of FIG. 11. Body member 51 defines central through bore 52. Upper collar member 53 is disposed at one end of said lockout sleeve 50, while optional tapered surface 54 is disposed at the opposite end of lockout sleeve 50 from said upper collar member 53. Circumferential groove 55 forms a slot or recess that extends around the circumference of said body member 51 and is oriented substantially perpendicular to the longitudinal axis of central bore 52.

Referring back to FIG. 3, a side view of IBOP assembly 10 of the present invention is depicted, In the preferred embodiment, said IBOP 10 of the present invention generally comprises mating upper body member 30 and lower body member 20. A locking clip 70 is received within aligned slots, and each clip 70 is secured in place using locking clip pin 71 (which can be threaded or otherwise fasten locking clip 70 in place), to prevent said upper body member 30 and lower body member 20 from rotating (unscrewing) relative to each other.

FIG. 4 depicts a side sectional view of IBOP assembly 10 of the present invention along line 4-4 of FIG. 3. Through bore 32 extends through said upper body member 30, while aligned through bore 22 extends through said lower body member 20. Clevis bracket members 33 extend from end 34 of upper body member 30.

IBOP assembly 10 further comprises a flapper assembly comprising flapper 40 having clevis bracket members 43, flapper pivot pin 41 and bias spring 42 (not depicted in FIG. 4). In the preferred embodiment, clevis bracket members 33 of upper body member 30 are received between clevis bracket members 43 of flapper 40. Each of said clevis bracket members 33 and 43 have aligned bores for receiving flapper pivot pin 41. In this configuration, flapper member 40 can pivot or rotate about said pivot pin 41.

Still referring to FIG. 4, tubular lockout sleeve 50 has body member 51 defining central through bore 52. Said tubular lockout sleeve 50 further comprises upper collar member 53 having a larger outside diameter dimension than that of body member 51. Optional tapered surface 54 can be disposed at the opposite end of lockout sleeve 50 from said upper collar member 53.

Flapper member 40 can rotate about an angle of approximately 90 degrees. In the open position, as depicted in FIG. 4, said flapper member 40 is disposed against the recessed inner wall of flapper housing 23 defined by lower body member 20. In this position, said flapper 40 does not extend into or otherwise restrict through bores 32 or 22.

Still referring to FIG. 4, transverse bore 36 is disposed through upper body member 30 and extends from the outer surface of said upper body member 30 to through bore 32. In the preferred embodiment, said transverse bore 36 is oriented substantially perpendicular to the longitudinal axis of through bore 32. Retention pin 60 and spring 61 are disposed within said transverse bore 36 and secured in place using cap 62. Spring 61 biases said retention pin 60 inward in the direction of bore 32 of upper body member 30.

In operation, IBOP assembly 10 of the present invention downward fluid flow through aligned through bores 32 and 22. Pivoting flapper 40, biased in a closed position by bias spring 42, prevents upward fluid flow (that is, in the opposite direction) through said aligned through bores 32 and 22.

In certain circumstances, it may be beneficial to lock flapper 40 in the open position. In such cases, lockout sleeve 50 can be run into the well on wireline or other conveying means. Because the outer diameter of body member 51 of tubular lockout sleeve 50 is smaller than the diameter of through bore 32 of upper body member 30, said body member 51 can be received within said through bore 32. Through bore 32 can include an inner profile or shape for receiving said collar member 53. Collar member 53 has a greater diameter than through bore 32 of upper body member 30, thereby limiting downward travel of said lockout sleeve 50. Further, retention pin 60 can be received within circumferential groove 55 to secure or “lock” said lockout sleeve 50 in place within IBOP assembly 10 and prevent axial movement of said lockout sleeve 50.

Due to the length of lockout sleeve 50, when said lockout sleeve 50 is installed, flapper 40 is prevented from closing, thereby preventing such flapper from impeding wireline operations being conducted through IBOP assembly 10. Such wireline and any connected tools can pass in an unobstructed manner through central bore 51 of lockout sleeve 50, thereby allowing operations to be performed at depths below said IBOP assembly 10. Further, such wireline and tools can be safely retrieved to the surface through said central bore 51 of lockout sleeve 50 without interference from flapper 40 or any other components of IBOP assembly 10.

The above-described invention has a number of particular features that should preferably be employed in combination, although each is useful separately without departure from the scope of the invention. While the preferred embodiment of the present invention is shown and described herein, it will be understood that the invention may be embodied otherwise than herein specifically illustrated or described, and that certain changes in form and arrangement of parts and the specific manner of practicing the invention may be made within the underlying idea or principles of the invention.

Claims

1. An internal blow out preventer comprising:

a) a body member having a top, a bottom, a longitudinal axis and a through-bore extending from said top to said bottom along said longitudinal axis;

b) a flapper pivotally connected to said body member, wherein said flapper permits fluid flow in one axial direction through said through bore but not the opposite axial direction; and

c) a tubular sleeve member adapted to be received within said through bore of said body member, wherein said tubular sleeve prevents said flapper from closing when said tubular sleeve member is installed in said through bore of said body member.

2. The internal blowout preventer of claim 1, further comprising:

a) a pin having a first end and second end, movably received within a transverse bore extending through said body member, wherein said transverse bore is oriented substantially perpendicular to said longitudinal axis of said body member, and said first end of said pin extends into said through bore;

b) a spring biasing said pin toward said through bore; and

c) a recess on the outer surface of said tubular sleeve for receiving said first end of said pin.

3. The internal blowout preventer of claim 2, wherein said recess on the outer surface of said tubular sleeve comprises a groove extending substantially around the circumference of said tubular sleeve.

4. A method of conducting wireline operations in a well having a drill string equipped with an internal blow out preventer, comprising:

a) installing an internal blowout preventer in a drill string, said internal blowout preventer comprising: i) a body member having a top, a bottom, a longitudinal axis and a through-bore extending from said top to said bottom along said longitudinal axis; ii) a flapper pivotally connected to said body member, wherein said flapper permits fluid flow in one axial direction through said through bore but not the opposite axial direction;

b) installing a tubular sleeve member within said through bore of said body member of said internal blowout preventer, wherein said tubular sleeve prevents said flapper from closing; and

c) conducting wireline operations through said tubular sleeve member.

5. The method of claim 4, wherein said internal blowout preventer further comprises:

a. a pin having a first end and second end, movably received within a transverse bore extending through said body member, wherein said transverse bore is oriented substantially perpendicular to said longitudinal axis of said body member, and said first end of said pin extends into said through bore;

b. a spring biasing said pin toward said through bore; and

c. a recess on the outer surface of said tubular sleeve for receiving said first end of said pin.

6. The method of claim 5, wherein said recess on the outer surface of said tubular sleeve comprises a groove extending substantially around the circumference of said tubular sleeve.