EP2876249B1

EP2876249B1 - Spherical-annular blowout preventer having a plurality of pistons

Info

Publication number: EP2876249B1
Application number: EP14191759.1A
Authority: EP
Inventors: Hernani G. Deocampo; Dean Madell
Original assignee: ZP INTERESTS LLC
Current assignee: ZP INTERESTS LLC
Priority date: 2013-11-22
Filing date: 2014-11-04
Publication date: 2017-07-19
Anticipated expiration: 2034-11-04
Also published as: SG10201407191RA; IN2014DE03195A; US20150144356A1; CN104653141A; KR20150059598A; HK1210820A1; EP2876249A1

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The following description relates to blowout preventers used in the oil and gas industry during oil and gas well drilling and work over to prevent escape of well bore pressure into the outside environment in the event of an unexpected pressure "kick" due to the influx of formation fluid or other uncontrolled situations. For example, an annular-spherical blowout preventer design may include multiple pistons and glands.

2. Description of Related Art

Well control is an important aspect of oil and gas exploration. For example, when drilling a well, safety devices must be put in place to prevent damage to equipment and, most importantly, to personnel resulting from unexpected events associated with drilling operations. Because of safety conditions and risk of blowouts devices known as blowout preventers (BOPs) are installed above the wellhead at the surface or on the sea floor in deep water situations to effectively seal a wellbore until measures can be taken to control the kick. Blowout preventers are large, specialized high-pressure valves or similar mechanical devices, typically installed redundantly in stacks and used to seal and control downhole pressure and monitor oil and gas wells to ultimately prevent the uncontrolled flow of liquids and gases during well drilling operations. Blowout preventers come in a variety of styles, sizes and pressure ratings and often several individual units serving various functions are combined to compose a blowout preventer stack. Some of the functions of a blowout preventer system include, but are not limited to, confining well fluid to the wellbore, providing a means to add fluid to the wellbore, allowing controlled volumes of fluid to be withdrawn from the wellbore, regulating and monitoring wellbore pressure, and sealing the wellhead.
In addition to controlling the downhole pressure and the flow of oil and gas, blowout preventers are intended to prevent tubing, tools and drilling fluid from being blown out of the wellbore when a blowout threatens. Blowout preventers are critical to the safety of crew, rig and environment, and to the monitoring and maintenance of well integrity. Thus, blowout preventers are intended to be fail-safe devices. Multiple blowout preventers of the same type are frequently provided for redundancy, an important factor in the effectiveness of fail-safe devices.
There are two major types of blowout preventers, annular and RAM. Annular BOPs are usually mounted to the very top of a BOP stack. The drilling crew then typically mounts a predetermined number of RAM BOPs below the annular blowout preventer. Blowout preventers were developed to cope with extreme erratic pressures and uncontrolled flow, often referred to as formation kick, emanating from a well reservoir during drilling. Kicks can lead to a potentially catastrophic event known as a "blowout." If a kick is detected, the annular is usually closed first and then the RAM is used as a backup if the annular should fail. Often times during operation BOPs are damaged and repair is difficult if not impossible when dealing with internal component damage such as pistons.
In drilling a typical high-pressure well, drill strings are routed through a blowout preventer stack toward the reservoir of oil and gas. As the well is drilled, drilling fluid, "mud", is fed through the drill string down to the drill bit, "blade," and returns up the wellbore in the ring-shaped void, annulus, between the outside of the drill pipe and the casing (piping that lines the wellbore). The column of drilling mud exerts downward hydrostatic pressure to counter opposing pressure from the formation being drilled, allowing drilling to proceed. When a kick occurs, rig operators or automatic systems close the blowout preventer units, sealing the annulus to stop the flow of fluids out of the wellbore. Denser mud is then circulated into the wellbore down the drill string, up the annulus and out through the choke line at the base of the BOP stack through chokes until downhole pressure is overcome. If the blowout preventers and mud do not restrict the upward pressures of a kick a blowout results, potentially shooting tubing, oil and gas up the wellbore, damaging the rig, and leaving well integrity in question.
A generic blowout preventer is for example known from US 2,609,836 . This document is directed to a control head and blowout preventer. A housing of the blowout preventer has a vertical bore there through. A packer comprising a massive annulus of resilient material is positioned within the housing with its bore aligned with the housing bore. The device furthermore comprises a pair of series of circularly arranged and angularly spaced rigid plates wherein the series is located, on each, at the opposite ends of and connected to the annulus. Furthermore vertically spaced shoulders are provided in the housing and receive the packer between them to limit the vertical movement of the packer with respect to the housing.
Further a blow-out preventer is known from US 2,207,149 . The blow-out preventer has an axial opening for a packing fit on a drill stem. It is proposed that a pair of breech lock members, one of which is threaded on the casing head is provided and means for rotating said pair into locking engagement and for rotating the locked pair on the casing head thread. Thereby the blow-out preventer fluid is secured tight in the casing head.

SUMMARY OF THE INVENTION

According to an example, a blowout preventer includes an upper housing comprising an inner ceiling with a cavity configured to accommodate a main seal, a lower housing comprising a plurality of internal fluidly interconnected cylinders, a plurality of annular pistons and glands configured to be placed within the plurality of internal fluidly interconnected cylinders, an energizing ring configured to be operated on by the annular pistons in order to operate the main seal, and disposed circumferentially within a void area of the lower housing, and an upper gland assembly configured to isolate the plurality of internal fluidly interconnected cylinders from the void area of the lower housing.
In another example, a blowout preventer includes a housing comprising a plurality of fluidly interconnected cylinders formed therein, a main seal positioned within the housing, a plurality of cylindrical sleeves removably placed within the plurality of fluidly interconnected cylinders, a plurality of annular pistons and glands configured to be placed within the plurality of cylindrical sleeves, and an energizing ring configured to be operated on by the annular pistons in order to operate the main seal.
In another example, a piston cartridge configured to be used in a blowout preventer includes a cylindrical sleeve forming the outer wall of the piston cartridge, an annular piston placed within the cylindrical sleeve, and a gland retained on a distal portion of the piston cartridge, wherein the annular piston comprises a hole configured to receive a piston rod.
In another example, a method of using a blowout preventer includes providing a piston cartridge, comprising a cylindrical sleeve, an annular piston, and a gland, into a cavity formed within the blowout preventer, connecting a piston rod of the blowout preventer to a hole formed within the annular piston of the piston cartridge; and covering the cavity of the blowout preventer using a bottom cover plate.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The foregoing summary, as well as the following detailed description, will be better understood when read in conjunction with the appended drawings. For the purpose of illustration, certain embodiments of the present disclosure are shown in the drawings. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an implementation of system, apparatuses, and methods consistent with the present invention and, together with the description, serve to explain advantages and principles consistent with the invention.

FIG. 1: illustrates a perspective view of an example of a blowout preventer assembly.
FIG. 2: illustrates a cross-sectional perspective view of the blowout preventer assembly connected according to one embodiment.
FIG. 3A: illustrates a cross-sectional elevation view of the blowout preventer assembly rotated approximately 90 degrees from that as shown in FIG. 2, according to one embodiment.
FIG. 3B: illustrates a cross-sectional elevation view of the blowout preventer assembly with Detail A of an annular piston and associated gland indicated according to one embodiment.
FIG. 3C: illustrates a magnified depiction of Detail A as shown in FIG. 3B of a cross-sectional side view of the annular piston and gland according to one embodiment.
FIG. 4: illustrates a cross-sectional view of an energizing ring utilized with one embodiment of the blowout preventer.
FIG. 5: illustrates a cross-sectional view of a lower housing utilized with one embodiment of the blowout preventer.
FIG. 6: illustrates a cross-sectional view of an upper housing utilized with one embodiment of the blowout preventer.
FIG. 7: illustrates a cross-sectional view of another example of a blowout preventer assembly.
FIGS. 7A and 7B: illustrate magnified depictions of an example of the blowout preventer including an adaptor ring with thru holes and a filter or wire mesh as shown in FIG. 7.
FIG. 8: illustrates a cross-sectional view of an example of a lower housing including an upper gland assembly and a cylindrical sleeve.
FIG. 9: illustrates a cross-sectional view of an example of the lower housing including an indicator/bleed port.
FIG. 9A: illustrates a magnified depiction of an example of the indicator/bleed port as shown in FIG. 9.
FIG. 10: illustrates a cross-sectional view of an example of a removable piston cartridge of the blowout preventer.

DETAILED DESCRIPTION OF THE INVENTION

Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The Figures and written description are provided to teach any person skilled in the art to make and use the inventions for which patent protection is sought. The invention is capable of other embodiments and of being practiced and carried out in various ways. Those skilled in the art will appreciate that not all features of a commercial embodiment are shown for the sake of clarity and understanding. Persons of skill in the art will also appreciate that the development of an actual commercial embodiment incorporating aspects of the present inventions will require numerous implementation specific decisions to achieve the inventors' ultimate goal for the commercial embodiment. While these efforts can be complex and time-consuming, these efforts nevertheless would be a routine undertaking for those of skill in the art having the benefit of this disclosure.
In addition, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. For example, the use of a singular term, such as "a" is not intended as limiting of the number of items. Also the use of relational terms, such as but not limited to, "top," "bottom," "left," "right," "upper," "lower," "down," "up," "side," and "surface" are used in the description for clarity in specific reference to the Figures and are not intended to limit the scope of the invention or the appended claims. Further, it should be understood that anyone of the features of the invention can be used separately or in combination with other features. Other systems, methods, features, and advantages of the invention will be or become apparent to one with skill in the art upon examination of the Figures and the detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present invention, and be protected by the accompanying claims.
Reference will now be made in detail to an implementation consistent with the present invention as illustrated in the accompanying drawings. For the purpose of clarification, embodiments described herein reference the term "fluid," which refers to a gas, liquid, as well as liquid solution with solid aggregates, as well as any other material that can reasonably be expected to flow.
Referring to FIG. 1, by way of non-limiting example, and consistent with embodiments of the invention, a blowout preventer assembly 1 is shown, wherein the blowout preventer assembly 1 is hydraulically actuated and is annular-spherical in overall design. When describing the operational function of the present embodiment of the blowout preventer assembly 1, the volume of hydraulic fluid to effectuate desired operation is about 4 gallons to "close" and about 3 ½ gallons to "open" a main seal 25 (see FIGS. 2 and 3A) of the blowout preventer assembly 1. Further, in the preferred embodiment, the inner dimensions of well pipe that can be accommodated can range from about 5 ½ inches to about 21 ¼ inches. All metal components utilized in manufacture of the present embodiment, when possible and not restricted by pressure constraints or other operational reasons, are manufactured and machined from commercially available 4130 steel. One skilled in the art will recognize that other diameters, types and thicknesses of steel or preferred materials can be utilized when taking into consideration safety and the high pressure functioning capacity of the present embodiment which can range in operation from 3,000 psi to 20,000 psi.
The blowout preventer assembly 1 will now be discussed in detail with reference to the cross-sectional views as shown in FIGS. 2 and 3A together, wherein FIG. 3A is rotated clockwise in view about 90 degrees as compared to the view depicted in FIG. 2. The blowout preventer assembly 1 comprises a plurality of constituent components that provide blowout prevention in oil and gas well operation through implementation and operation of a plurality of annular pistons 40 (also shown in specific detail in FIG. 3C), as will be further described. The blowout preventer assembly's 1 containment structure is generally configured having a lower housing 10 with a plurality of internal fluidly interconnected cylinders 160, an upper housing 5 (also shown in specific detail in FIG. 6), a one piece energizing ring 15 (also shown in specific detail in FIG. 4), and a plurality of individual bottom cover plates 65. The blowout preventer assembly 1 also comprises a commercially available off-the-shelf main seal 25 with a plurality of main seal ribs 27, an adaptor ring 30, a plurality of glands 45 (also shown in specific detail in FIG. 3C) dedicated to each annular piston 40, and various dedicated and associated seals and threaded attachments which will be detailed hereinbelow with associated components. The main seal is positioned over a bowl 155 machined into one end of the energizing ring 15.
Referring to FIGS. 2, 3A and 6 together, the present embodiment of the blowout preventer assembly 1 comprises the upper housing 5 having a concave inner design defining a spherical or concave shaped main bore 26 in an inner ceiling 28 of the upper housing 5 that allows for accommodation, fitment and operation of the main seal 25. The main bore's 26 inner ceiling's 28 concave design provides circumferential closure guidance and integrity to the main seal 25. The main seal ribs 27 function in conjunction with the inner ceiling 28 shape to cause sealing closure around and contact with the outer diameter of pipe (not shown) positioned within the lower housing column bore 130 when demand for closure of the blowout preventer assembly 1 is required by induced well bore factors. The upper housing 5 further comprises a series of spaced about female threaded connections 9 for receiving upper housing bolts 8 used to provide attachment and securement of other desired gas or oil well/drilling components. Further provided in an upper housing attachment end 4 of the upper housing 5 are a plurality of spaced apart individually machined bifurcated upper housing retainer lugs 150 for secured attachment with the lower housing 10 as will be described below. The bifurcated upper housing retainer lugs 150 are positionally machined in a bifurcated spaced apart protruding fashion about an outer circumference of an upper housing attachment end 4, as shown in FIG. 6. The bifurcated upper housing retainer lugs 150 operate to interlace, lock and secure, once mated, the lower housing 10 with the upper housing 5 via a quarter turn twist, thus securing both together.
Referring to FIGS. 2, 3A, and 5 together, the present embodiment of the blowout preventer assembly 1 comprises the lower housing 10 having a unitary structure design that provides for and contains much of the functional components and machined portions of the overall blowout preventer assembly 1. Specifically, the unitary structure of the lower housing 10 defines a generally cylindrical shape having a lower housing flange 75, a plurality of machined bifurcated lower housing retainer lugs 145, a lower housing wall 167, a machined upper seat 6, a machined upper shoulder 119, a lower seat 31, a lower housing column 164 having a lower housing column wall 165 which defines an inner area of the lower housing column bore 130, lower housing column wall seals 166, and a plurality of internal fluidly interconnected cylinders 160 machined into a cylinder plane surface 163 wherein each cylinder has a dedicated cylinder fluid channel 161. Each of the previous mentioned components and its integral function will be further detailed hereinbelow.
An upper shoulder seal 120 and an adaptor ring upper seal 140 are utilized as mud and cutting scrapers and are designed to prevent ingress of mud and cuttings into a plurality of column primary seals 122 and into a plurality of primary seals 95 and as a result prolongs the overall life of each. The upper shoulder seal 120 is removably attached to and circumferentially rests around and on the surface of an upper shoulder 119 via a plurality of upper shoulder seal retaining bolts 105 and is further secured into position via a retainer lip 118 on the energizing ring 15. An adaptor ring 30, having a plurality of adaptor ring primary seals 95 and a plurality of adaptor ring secondary seals 100, is removably disposed on a lower seat 31 around the outer diameter of the adaptor ring 30 and covering the area adjacent to the adaptor ring upper seal 140 and the adaptor ring primary seal 95 to prevent external escape of pressure built up in the blowout preventer assembly 1.
The lower housing 10 mates for operation with the upper housing 5 and the bifurcated upper housing retainer lugs 150 in a rotatable locking attachment fashion via a plurality of spaced apart and machined bifurcated lower housing retainer lugs 145 similar to those machined into the upper housing 5 described above. The plurality of bifurcated lower housing retainer lugs 145, however, are postionally machined in a bifurcated spaced apart protruding fashion about an inner circumference of a lower housing attachment end 11, as shown in FIG. 5. The bifurcated lower housing retainer lugs 145 function to interlace, lock and secure, the lower housing 10 with the upper housing 5 via a quarter tum twist once mated together and the upper housing 5 is properly seated on the upper seat 6 of the lower housing 10. The bifurcated upper housing retainer lug 150 and bifurcated lower housing retainer lug 145 connection design also allows rapid disassembly and assembly in-house and in the field.
The present embodiment of the lower housing 10, as shown in FIGS. 2, 3A and 5 permits flow supply of demanded hydraulic fluid into the plurality of internal fluidly interconnected cylinders 160 through two primary supply ports, either an open port 305 or close port 310. The close port 310 supplies hydraulic pressure in the bottom or close side of each annular piston 40 to activate the main seal 25. When the main seal 25 is activated from hydraulic fluid pressure through the close port 310 the blowout preventer assembly 1 is closed and the well bore is isolated and thus prevents well bore pressure from migrating above the main seal 25. When the main seal 25 is activated from the open port 305, hydraulic fluid pressure is supplied into an open side of the annular piston 40. The open and close function will be further described below.
As shown with specific reference to FIG. 5, in a preferred embodiment, six (6) internal fluidly interconnected cylinders 160 are machined into the steel body of the lower housing 10. Each internal fluidly interconnected cylinder 160 is machine bored into a cylinder plane surface 163 that is located in a radial area bounded by the lower housing wall 167 and the lower housing column wall 165. Each of the internal fluidly interconnected cylinders 160 is substantially equally spaced apart from adjacent cylinder. The fluid interconnectivity of each internal fluidly interconnected cylinders 160 within the lower housing 10 is achieved via implementation of the machined cylinder fluid channel 161 disposed in a horizontal plane within a circumferential portion of a cylinder wall 162 within each of the internal fluidly interconnected cylinders 160.
A gland 45 having a circumferential channel 86, as shown in FIGS. 2, 3A, and 3C, with a plurality of gland seals 85 is disposed in a distal portion of the internal fluidly interconnected cylinder 160, wherein the distal portion of the internal fluidly interconnected cylinders 160 diameter that surrounds the gland 45 is of a second diameter larger than the first inner diameter of the internal fluidly interconnected cylinder 160 that encloses the annular piston 40. Such smaller inner diameter portion of the cylinder 160 that encloses the annular piston 40 serves as a stop lip 146 and prevents movement during operation, or otherwise, of the gland 45 into the internal fluidly interconnected cylinder 160 portion enclosing the annular piston 40. During all operations the gland 45 is removably fixed in a stationary position and attached to a bottom cover plate 65 with a half tap gland plug 60. The only time the gland 45 is removed is for repair or replacement of the annular piston 40 or the gland 45. The gland 45 can also be used as a secondary access to provide hydraulic power into the annular piston 40. The gland 45 is the primary component that provides for test access and isolation of the annular pistons 40.
As shown in FIGS. 3B and 3C an isolation and test plug 168 is provided for conducting pressure testing on an individual internal fluidly interconnected cylinder 160 or an annular piston 40. The isolation and test plug 168 can be used when inserted into the gland test plug cavity 55 via an access aperture 115 to isolate an inoperable annular piston 40 from all other annular pistons 40 within the blowout preventer assembly 1, thereby preventing substantial downtime to drilling operations. During normal operations, the isolation and test plug 168 is removed and is not present and is replaced by the half tap gland plug 60 for continued operations. FIGS. 2 and 3C show the cross section of the gland 45. The gland 45 has two longitudinal gland channels 50 traversing an inner portion of the gland 45. The gland channel 50 allows hydraulic fluid to flow to the annular piston 40 in the same internal fluidly interconnected cylinder 160 and allows hydraulic fluid to flow to the cylinder wall 162 and into the cylinder fluid channel 161, thereby providing the aforementioned internal fluidly interconnected cylinder's 160 interconnectivity. The bottom cover plates 65 are positioned in a plate channel 66 and are removably attached by a plurality of threaded fasteners, such as bottom cover plate bolts 70 into the lower housing 10 to secure the glands 45 in place and to provide for easy access to the annular pistons 40 and the gland 45 for maintenance and/or removal.
The diameter and bore length of the internal fluidly interconnected cylinders 160 are a predetermined factor and are based on of the overall size and dimensions of the blowout preventer assembly 1 design which is dictated by operational necessity. Each annular piston 40 is fabricated having an annular design of predetermined diameter to provide proper fitment within the inner diameter of the internal fluidly interconnected cylinder 160. The diameter and thickness of each annular piston 40 is dependent upon pressure requirements and other specifications of the overall blowout preventer assembly 1 size and design. One skilled in the art will recognize the overall blowout preventer assembly 1 size requirements and the internal fluidly interconnected cylinder 160, annular pistons 40 and other herein described components and associated sizing required can vary in size, length, diameter and type of steel for proper operation. The preferred embodiment can operate in the field to provide blowout prevention capability with fewer than six (6) functioning annular pistons 40 disposed in the internal fluidly interconnected cylinders 160. However, blowout prevention is severely diminished or threatened with three (3) or fewer operating internal fluidly interconnected cylinders 160 and/or annular pistons 40.
As shown in FIGS. 2, 3C and 4, the annular piston 40 is removably attached to a surface of a heel 16 on the energizing ring 15 by way of a piston connector 90 for enabling operation of the blowout preventer assembly 1 to facilitate proper and sufficient component movement for ultimate closure of the main seal ribs 27 of the main seal 25 around a pipe (not shown) when positioned within the lower housing column bore 130 and closure is demanded through a close port 310 due to hydraulic fluid operation. The annular pistons 40 have a plurality of side perimeter grooves 81 for accommodating associated piston seals 80 to prevent pressurized fluid leakage into undesired portions of the internal fluidly interconnected cylinder 160.
As shown in FIGS. 2 and 3A, the lower housing 10 and upper housing 5 also enclose the energizing ring 15. The energizing ring 15 (detailed in FIG. 4) is disposed such that at least three of the heels 16, being bifurcated in a equidistant and spaced apart fashion about a distal end of the energizing ring 15 can functionally engage at least three (3), preferably six (6), independent annular pistons 40, wherein the internal fluidly interconnected cylinders 160 and annular pistons 40 form a honeycomb design within the lower housing 10. The energizing ring 15 heels 16 are each separately connected to one side of the heels' 16 accompanying annular pistons 40 via a piston connector 90 comprised of a male threaded bolt, seals and a nut. The piston connector 90 allows removal of either the annular piston 40 or the energizing ring 15.
Now, the close and open operation of the blowout preventer assembly 1 will be described with reference to the Figures in general but with specific reference to FIG. 3A. To close the blowout preventer assembly 1, hydraulic fluid pressure is primarily supplied through the close port 310. The hydraulic pressure provided exerts force on a piston close side 169 to move the annular pistons 40 against the heel 16 of the energizing ring 15. The force generated by the hydraulic pressure will then be transferred to the main seal 25 via the energizing ring 15. This will cause closure to the main bore 26 of the blowout preventer assembly 1 thereby preventing all well bore pressure from escaping.
To open the blowout preventer assembly 1, hydraulic pressure is primarily supplied through the open port 305. The hydraulic pressure provided exerts force on a piston open side 170 to move the annular pistons 40 in a direction toward the gland 45. The force generated by the hydraulic pressure will then be transferred to the energizing ring 15 and will cause opening of the main seal 25 and as a result will open the main bore 26 of the blowout preventer assembly 1.
FIG. 7 is a diagram illustrating another example of a blowout preventer assembly 2. The blowout preventer assembly 2 may include any of the components of blowout preventer assembly 1 as described above, and may operate in the same way. For example, the blowout preventer assembly 2 includes the upper housing 5, the lower housing 10, the main seal 25, the adaptor ring 30, the plurality of annular pistons 40 operating within the plurality of internal fluidly interconnected cylinders 160 formed in the lower housing 10, the plurality of glands 45 formed on the bottom of the fluidly interconnected cylinders 160, the bottom cover plates 65 covering the fluidly interconnected cylinders 160, among other components of the blowout preventer assembly 1. Additionally, blowout preventer assembly 2 includes an open port 305 and close port 310 for the supply of hydraulic fluid pressure to the annular pistons 40 and for operating the main seal 25. A description of these components and their operations is provided in detail with reference to FIGS. 1-6 above.
Referring to the example shown in FIG. 7, the blowout preventer assembly 2 includes an energizing ring 215 which may operates in a similar way as the energizing ring 15 of the blowout preventer assembly 1. In this example, energizing ring 215 is placed within a void area 230 which is separated from the fluidly interconnected cylinders 160 by an upper gland assembly 245. Accordingly, the upper gland assembly 245 isolates and protects the fluidly interconnected cylinders 160 and components therein, such as the annular pistons 40 and the plurality of glands 45, from debris and well fluid which may enter the blowout preventer 2 during drilling operations. For example, the upper gland assembly 245 may include a plurality of upper gland assemblies 245 each being used with one of the plurality of fluidly interconnected cylinders 160, or the upper gland assembly 245 may be one assembly wrapping around the circumference of the blowout preventer 2 to isolate all fluidly interconnected cylinders 160. The energizing ring 215 is connected to the annular pistons 40 by a piston rod 216, which will be described in greater detail with reference to FIG. 8 below.
Still referring to FIG. 7, blowout preventer assembly 2 includes a cylindrical sleeve 250 which is removably placed within the fluidly interconnected cylinder 160 of the lower housing 10. In this example, hydraulic fluid pressure drives the movement of the annular piston 40 within the cylindrical sleeve 250, and a gland 45 is attached to the bottom of the cylindrical sleeve 250. The cylindrical sleeve 250 may be removed entirely from the blowout preventer assembly 2 by removing the bottom cover plate 65. This will be described in greater detail with reference to FIG. 10 below.
In an aspect, a removable cylindrical sleeve 250 protects the walls of the fluidly interconnected cylinders 160 of the lower housing 10 from corrosion or damage, and provides a cheaper and faster process of refurbishing or reworking the lower housing 10. Further, the cylindrical sleeve 250 may be replaced with a new or refurbished cylindrical sleeve 250 in a quick and easy replacement process. The cylindrical sleeve 250 may be formed of any material, and is preferably formed of a light weight, resilient, and non-corrosive material. For example, the cylindrical sleeve 250 may be formed of aluminum, Grade 410 Stainless Steel, or 17-4 PH Stainless Steel.
FIGS. 7A and 7B are diagrams illustrating magnified depictions of an example of the blowout preventer assembly 2 including the adaptor ring 30 having thru holes 280 and a filter or wire mesh 285. In this example, the adaptor ring 30 includes one or more thru holes 280, each of which extends through the entire thickness of the adaptor ring 30. Any number of thru holes 280 may be formed in any number of positions on the adaptor ring 30, and in a preferred example, eight thru holes 280 are formed in equally spaced positions around the circumference of the adaptor ring 30. Also, referring to FIG. 7B, a filter or wire mesh 285 is formed in a slot within the upper circumference of the adaptor ring 30 such that air may move freely between the void area 230 and the upper area of the blowout preventer 2 which holds the main seal 25. In an example, the thru holes 280 and the filter or wire mesh 285 of the adaptor ring 30 allow the void area 230 to breathe freely thus preventing hydraulic lock which may result from pressure buildup within the void area 230, while the filter or wire mesh 285 protects the void area 230 from wellbore debris.
FIG. 8 is a diagram illustrating a cross-sectional view of an example of the lower housing 10 including the upper gland assembly 245 and the cylindrical sleeve 250. Referring to FIG. 8, the cylindrical sleeve 250 includes the annular piston 40 operating therein and the gland 45 attached at the bottom of the cylindrical sleeve 250. The gland 45 includes the gland plug 60 and longitudinal gland channels 50 traversing an inner portion of the gland 45 for receiving hydraulic fluid pressure as described above.
Referring to FIG. 8, the annular piston 40 is connected to the energizing ring 215 by a piston rod 216 which includes a shoulder bolt 217 and a connector 218. The shoulder bolt 217 is connected to the bottom of the energizing ring 215, and the connector 218 is connected to the annular piston 40 by projecting therethrough and connecting to a corresponding retainer 222 on the opposite side. In this example, the connector 218 is threadedly engaged with the retainer 222. A face seal 221 may be placed on the upper side of the annular piston 40 and around the connector 218. Further, the upper gland assembly 245 includes a plurality of gland seals 85 within its outer and inner diameters for preventing intrusion of wellbore fluid and debris. The upper gland assembly 245 includes a plurality of fastening holes 246 for receiving fasteners and securing the upper gland assembly 245 into the lower housing 10.
FIG. 9 is a diagram illustrating a cross-sectional view of an example of the lower housing 10 including an indicator/bleed port 290 and interconnecting holes 251, and FIG. 9A is a diagram illustrating a magnified view of the indicator/bleed port 290. The indicator/bleed port 290 may include an indicator 295 for determining conditions within the void area 230 such as pressure or temperature. In this example, the indicator 295 is a pressure indicator or bleed port for indicating to an operator the pressure within the void area 230. Also, in an example, an operator may access the void area 230 through the indicator/bleed port 290 with a number of different tools.
FIG. 10 is a diagram illustrating a cross sectional view of the internal fluidly interconnected cylinders 160 and a removable piston cartridge 200 in a nearly removed position. Referring to FIG. 10, the removable piston cartridge 200 is a modular unit which includes the annular piston 40 and the cylindrical sleeve 250. Also, the removable piston cartridge 200 may include the gland 45 at the bottom of the cylindrical sleeve 250 as shown in FIG. 8. The removable piston cartridge 200 may be sold and manufactured separately or together with the blowout preventer assembly 2. Also, each of the components of the removable piston cartridge 200, including the annular piston 40, the cylindrical sleeve 250, and gland 45, may be sold and used as a modular unit together or separately.
The removable piston cartridge 200 may easily and quickly be removed from the fluidly interconnected cylinders 160 as a modular unit or in separate components. For example, an operator or a machine may first remove the bottom cover plate 65. The gland plug 60 of the gland 45 may then be removed, and the gland 45 may subsequently be removed. An operator or machine may then loosen and remove retainer 222, as shown in FIG. 8, for detaching the connector 218 from the piston 40. The sleeve 250 including the piston 40 may then be removed from the fluidly interconnected channel 160 as illustrated in FIG. 10. In another example, each of the components, such as the cylindrical sleeve 250, the annular piston 40, and the gland 45 may be individually removed or replaced without removing or replacing the entire piston cartridge 200 as a modular unit.
Referring to FIGS. 9 and 10, the lower housing 10 includes inner-connection holes 251 which allow the interconnection of the fluidly interconnected cylinders 160, and the cylindrical sleeves 250 include corresponding connection holes 252 which allow the interconnection of the cylindrical sleeves 250. In this example, the uniform actuation of the main seal 25 is ensured through the equal distribution of hydraulic fluid pressure formed between the interconnected cylindrical sleeves 250. Accordingly, the operation of the annular piston 40 within the cylindrical sleeve 250 may be similar to the operations described above for the blowout preventer assembly 1. Hydraulic fluid pressure is introduced through an open port 305 for pushing down the annular piston 40 and opening the main seal 25, and hydraulic fluid pressure is introduced through a close port 310 for pushing up the annular piston 40 and closing the main seal 25.
It should be appreciated by one of ordinary skill in the art that the dimensions of the cylindrical sleeve 250 may vary, but the cylindrical sleeve 250 should be sized to fit within the fluidly interconnected cylinders 160. In an example, an inner diameter of a fluidly interconnected cylinder 160 is 9.5 inches, the outer diameter of the cylindrical sleeve 250 is 9.48 inches, the inner diameter of the cylindrical sleeve 250 is 8.12 inches, and the height of the cylindrical sleeve 250 is 14 inches. Nevertheless, it should be appreciated that a number of different dimensions may be used for any of the components of the blowout preventer assembly 1 and the blowout preventer assembly 2, and the dimensions described herein are not limiting.
One of skill in the art will recognize that the embodiments described above are not limited to any particular size and the size of the blow out preventer and will depend upon the particular application and intended components. It will be appreciated by those skilled in the art that changes could be made to the embodiments described above. It is understood, therefore, that the invention disclosed herein is not limited to the particular embodiments disclosed.

Claims

A blowout preventer (1), comprising:
an upper housing (5) comprising an inner ceiling (28) with a cavity configured to accommodate a main seal (25);

a lower housing (10); and

an energizing ring (15) configured to be operated on by the annular pistons (40) in order to operate the main seal (25), and disposed circumferentially within a void area (230) of the lower housing (10); characterized in that

the lower housing comprises a plurality of internal fluidly interconnected cylinders (160) and in that the blowout preventer (1) further comprises a plurality of annular pistons (40) and glands (45) configured to be placed within the plurality of internal fluidly interconnected cylinders (160), wherein the pistons (40) are placed within a cylindrical sleeve (250) comprised by a piston cartridge (200); and

an upper gland assembly (245) configured to isolate the plurality of internal fluidly interconnected cylinders (160) from the void area (230) of the lower housing (10).
The blowout preventer of claim 1, further comprising a plurality of cylindrical sleeves (250) configured to be removably placed within the plurality of internal fluidly interconnected cylinders (160), each of the cylindrical sleeves (250) configured to hold one of the plurality of annular pistons (40).
The blowout preventer of claim 1 or 2, further comprising an adaptor ring (30) positioned between the concave shaped cavity of the upper housing (5) and the void area (230) of the lower housing (10), the adaptor ring (30) comprising a wire mesh (285) surrounding a circumference of the adaptor ring (30) and a thru-hole extending through a thickness of the adaptor ring (30).
The blowout preventer of one of the preceding claims, further comprising an indicator port for determining a pressure level within the void area (230).
The blowout preventer of one of the preceding claims, wherein the plurality of internal fluidly interconnected cylinders (160) each comprises a dedicated cylinder fluid channel (161) disposed within a portion therein, wherein the cylinder fluid channel (161) permits hydraulic fluid interconnectivity of each of the plurality of internal fluidly interconnected cylinders (160).
The blowout preventer of one of the claims 2 to 5, wherein the plurality of internal fluidly interconnected cylinders (160) each comprises a dedicated cylinder fluid channel (161) disposed within a portion therein, and the plurality of cylindrical sleeves (250) comprises one or more corresponding connecting holes (251) disposed therein for permitting hydraulic fluid interconnectivity of each of the plurality of internal fluidly interconnected cylinders (160) and each of the plurality of cylindrical sleeves (250).
The blowout preventer of one of the preceding claims, wherein the lower housing (10) comprises an open port (305) and a close port (310) for accommodating hydraulic connections for providing and relieving hydraulic fluid to cause the annular pistons (40) to force the energizing ring (30) in a direction to open or close the main seal (25), wherein preferably hydraulic fluid flows through the close port (310) to the gland (45), wherein each gland (45) further comprises a plurality of longitudinal gland channels (50) traversing the diameter of the gland (45) and a circumferential channel about the circumference of the gland (45), wherein each of the longitudinal gland channels (50) and the circumferential channels combine in design and function to accommodate the hydraulic fluid flow to responsively effectuate movement of the piston (40) and energizing ring (30) in a direction to cause the seal (25) to close.
The blowout preventer assembly of one of the claims 2 to 7, wherein each of the plurality of cylindrical sleeves (250) has a first inner diameter for properly accommodating an outer diameter of each of the annular pistons (40) and a second larger inner diameter for accommodating an outer diameter of each of the glands (45), such that the juncture of the first inner diameter and the second inner diameter form a stop lip (146), wherein preferably each of the glands (45) is positionally retained within a distal portion of each of the plurality of cylindrical sleeves (250) by the stop lip (146).
The blowout preventer assembly of one of the preceding claims, further comprising a piston rod (216) for connecting the energizing ring (30) to one of the plurality of annular pistons (40), wherein the upper gland assembly (245) comprises a hole for receiving the piston rod (216).
A piston cartridge (200) configured to be used in a blowout preventer (1) according to one of the preceding claims, comprising: a cylindrical sleeve (250) forming the outer wall of the piston cartridge (200); an annular piston (40) placed within the cylindrical sleeve (250); and a gland (45) retained on a distal portion of the piston cartridge (200), wherein the annular piston (40) comprises a hole configured to receive a piston rod (216).
The piston cartridge of claim 10, further comprising connecting holes formed within the cylindrical sleeve (250) for allowing the fluid interconnectivity of the piston cartridge (200) with an internal environment of the blowout preventer (1), and/or further comprising a retainer (222) for securing the annular piston (40) to the piston rod (216), wherein in response to removing the retainer (222), the piston cartridge (200) is detachable from the piston rod (216).
A method of using a blowout preventer (1), comprising: providing a piston cartridge (200), comprising a cylindrical sleeve (250), and an annular piston (40), into a cavity formed within the blowout preventer (1); characterized in that the method further comprises providing a gland (45) in the cavity; connecting a piston rod (216) of the blowout preventer (1) to a hole formed within the annular piston (40) of the piston cartridge (200); and covering the cavity of the blowout preventer (1) using a bottom cover plate.
The method of claim 12, further comprising removing the piston cartridge (200), wherein the removing of the piston cartridge (200) comprises: removing the bottom cover plate (65); removing the gland (45); detaching a retainer holding the piston rod (216) within the hole of the annular piston (40) in order to detach the annular piston (40) from the piston rod (216); simultaneously removing the cylindrical sleeve (250) and the annular piston (40), wherein preferably the removing of the piston cartridge (200) is performed in order to replace or refurbish the piston cartridge (200), or in order to rework the cavity of the blowout preventer (1).