Not applicable.
Not applicable.
Not applicable.
Embodiments disclosed herein generally relate 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. Specifically, embodiments discussed herein relate to an annular-spherical blowout preventer design having multiple pistons and glands.
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well fluid to the wellbore, providing a means to add fluid to the wellbore, allowing controlled volumes of fluid to be withdrawn from the wellbore, regulating and monitoring wellbore pressure, and sealing the wellhead.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.
In accordance with the teachings provided herein for a blowout preventer, one embodiment provides a blowout preventer assembly comprising a containment structure, wherein the containment structure comprises a unitary lower housing with a plurality of lower housing bifurcated retainer lugs disposed circumferentially about an attachment end of the lower housing, wherein the lower housing further includes a plurality of internal fluidly interconnected cylinders; a plurality of annular pistons and glands engaging the plurality of fluidly interconnected cylinders in the lower housing; a one piece energizing ring having a bowl in one end portion, wherein the energizing ring is operationally disposed circumferentially about a portion of the lower housing and in engagement with the plurality of annular pistons; an upper housing having an integral structure with a plurality of upper housing bifurcated retainer lugs for interlace quarter turn engagement with the lower housing plurality of bifurcated retainer lugs, wherein the upper housing further includes an inner ceiling with a spherical, concave shaped main bore for accommodating a main seal positioned over the bowl portion, wherein the lower housing and upper housing operationally enclose the one piece energizing ring, annular pistons, glands and seal; and a plurality of bottom plates for sealing the lower housing from an outside environment.
In another embodiment, a blowout preventer is provided comprising a lower housing having a unitary generally cylindrical shaped structure with a plurality of bifurcated retainer lugs; a plurality of internal fluidly interconnected cylinders configured in a plane surface of the integral structure, wherein each internal fluidly interconnected cylinder includes a dedicated cylinder fluid channel disposed therein a portion of a cylinder wall; a center column defining a center bore for accommodating a well pipe, wherein the center column comprises a plurality of seals; and a flange mounting portion disposed at a distal end of the center column.
In yet another embodiment, a blowout preventer is provided comprising an energizing ring having a generally cylindrical, one-piece integral structure having a bowl shaped surface opening machined into a first end portion of the energizing ring; and a plurality of bifurcated heel shaped mounting elements machined into a second end portion of the energizing ring.
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.
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 embodiments 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 any one 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
The blowout preventer assembly 1 will now be discussed in detail with reference to
Referring to
Referring to
An upper shoulder seal 120 and an adapter 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 adapter ring 30, having a plurality of adapter ring primary seals 95 and a plurality of adapter ring secondary seals 100, is removably disposed on a lower seat 31 around the outer diameter of the adapter ring 30 and covering the area adjacent to the adapter ring upper seal 140 and the adapter 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 positionally machined in a bifurcated spaced apart protruding fashion about an inner circumference of a lower housing attachment end 11, as shown in
The present embodiment of the lower housing 10, as shown in
As shown with specific reference to
A gland 45 having a circumferential channel 86, as shown in
As shown in
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 without departing from the scope and spirit of the invention. 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
As shown in
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
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.
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 without departing from the broad inventive concept thereof. It is understood, therefore, that the invention disclosed herein is not limited to the particular embodiments disclosed, and is intended to cover modifications within the spirit and scope of the present invention.
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Number | Date | Country | |
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20150144813 A1 | May 2015 | US |