Patent Application
20160084031
Not applicable.
Not applicable.
Not applicable.
1. Field
The following description relates to blowout preventers used in the oil and gas industry during well drilling. For example, a ram-type blowout preventer is used to prevent escape of well bore pressure into the outside environment in the event of an unexpected pressure due to the influx of formation fluid or in other uncontrolled situations.
2. Description of Related Art
Well control is an important aspect of oil and gas exploration. Typically, 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 risks 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 specialized high-pressure valves typically installed 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. Additionally, blowout preventers are typically used to prevent tubing, tools and drilling fluid from being blown out of the wellbore when a blowout threatens. Blowout preventers come in a variety of styles, sizes and pressure ratings and several units serving various functions are typically combined to compose a blowout preventer stack. Blowout preventers may perform any of a variety of functions such as confining well fluid to the wellbore, providing means to add fluid to the wellbore, allowing controlled volumes of fluid to be withdrawn from the wellbore, regulating and monitoring wellbore pressure, centering and hanging off the drill string in the wellbore, shutting in the well, preventing the flow of formation fluid, and sealing the well.
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. As recommend by authorities and required by various regulations, blowout preventers must be regularly tested, inspected, and refurbished. Blowout preventers typically include one set of corresponding ram blocks, and when the ram blocks need to be replaced or refurbished, companies are required by law to retest the entire blowout preventer stack. This may take long periods of time and may incur great expenses. A number of blowout preventers, including different types of ram blocks, are typically needed on the blowout preventer stack in order to serve a variety of different functions.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
According to an example, a ram block carrier includes an opening, an upper shelf within the opening configured to hold an upper ram block, and a lower shelf within the opening configured to hold a lower ram block.
In another example, a housing of a blowout preventer includes a bore, a first cavity on a side of the bore, a second cavity on another side of the bore, and inside walls, adjacent to the first and second cavities, each comprising an opening which allows a ram block to access the bore.
In another example, a blowout preventer includes a housing, a ram block carrier configured to move within the housing, and one or more ram blocks configured to be placed within the ram block carrier.
In another example, a method of operating a blowout preventer includes moving a ram block carrier within the blowout preventer, and moving a ram block of the ram block carrier towards a pipe going through a bore of the blowout preventer.
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 examples of the present description 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 description and, together with the description, serve to explain advantages and principles consistent with the invention.
Throughout the drawings and the detailed description, unless otherwise described, the same drawing reference numerals will be understood to refer to the same elements, features, and structures. The relative size and depiction of these elements may be exaggerated for clarity, illustration, and convenience.
The following detailed description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatuses, and/or systems described herein. Accordingly, various changes, modifications, and equivalents of the systems, apparatuses and/or methods described herein will be suggested to those of ordinary skill in the art. Also, descriptions of well-known functions and constructions may be omitted for increased clarity and conciseness.
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,” are used in the description for clarity 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 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 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.
Referring to
The housing 110 includes a rear door 130 which is shown in a closed position in
The housing 110 includes ram doors 140 which may be opened for inspecting, replacing, or removing components within the blowout preventer 100 such as ram block carriers, ram blocks, or other components. In this example, two ram doors 140 are attached to the body of the housing 110 using fasteners (not shown) similar to the fasteners 132 used for bolting the rear door 130. The ram doors 140 may include a number of holes 144 arranged around the doors 140 and configured to receive fasteners which are to be bolted to holes 112 formed within the housing 110. The ram doors 140 may be attached to the housing 110 using door hinges 142 so that the doors may be swung to an open position about the hinges 142 once the fasteners are removed.
Referring to
Referring to
In an example, the ram block carrier 160 includes an upper shelf 165 and a lower shelf 164 for receiving an upper ram block 182 and a lower ram block 184. The carrier 160, including the ram blocks 182, 184 installed therein, can be seen in
Further, the ram block carriers 160 may be smaller in height, width, and length than the cavities 124 of the housing 110. This allows the ram block carriers 160 to move up and down within the housing 110. It should be appreciated that the ram block carriers 160 may be formed according to a variety of different sizes based on the types and sizes of the ram blocks 182, 184 used within the ram block carriers 160. In an example, the carriers 160 may accommodate 3 inch thick or 5 inch thick ram blocks on the upper and lower shelves 164, 165. The height of the ram block cavities 124 of the housing 110 may be at least two times the height of the openings formed within the interior wall of the housing 110. The upper and lower ram blocks 182, 184 may have the same size or may have different sizes. Also, the upper and lower ram blocks 182, 184 may be of the same type or may be of different types. For example, the upper ram blocks 182 and the lower ram blocks 184, or three or more ram blocks installed within the blowout preventer 100, may include any one or more of pipe, blind, shear, and blind shear ram blocks.
For purposes of understanding the movements within the blowout preventer 100, the actuation of the ram blocks 183, 184 into an open, retracted position and closed, engaged position, and the actuation of the ram block carriers 160 into an upper and lower position will be described below. Regarding the movement of the ram blocks 183, 184, the blocks 183, 184 are moved between a retracted position and an engaged position about the pipe of the bore 120 using a hydraulic actuator 170 or a mechanical override stem 190 which will be described below with reference to
Referring to the example illustrated in
In the event of failure of the hydraulic actuator 170 or as an alternative to hydraulic actuation, blowout preventer 100 includes override mechanical actuator stem 190 for mechanical actuation of the ram blocks 182, 184. Mechanical actuator stem 190 is placed on the end of a stem protector 192 using roller bearings 194 which allow the stem 190 to be twisted for initiating mechanical actuation. When the stem 190 is twisted manually by an operator or using a machine, rotation of the stem 190 causes a threaded push rod 196 within the stem to pull away from the stem 190 and to be pushed inwardly towards the housing 110. This in turn pushes the entire actuating system, including the exterior actuating rod 172, the piston 174, and the interior actuating rod 173, into the ram block 182 for actuating into an engagement position. It should be appreciated that the length of the actuator stem 190 and push rod 196 is at least sufficient to extend the ram block 182 into an entirely engaged position, however, a number of lengths and sizes may be adopted and are appreciated to a person having ordinary skill in the art.
The stem protector 192 may include windows 193 which allow an operator to monitor the hydraulic and mechanical actuation of the ram blocks 182, 184. For example, the push rod 196 includes an end holder 197 which receives the exterior actuating rod 172. The end holder 197 includes one or more holes showing the position of the exterior actuating rod 172 with respect to the end holder 197. When the hydraulic actuator 170 is in the retracted position, an operator is able to see that the exterior actuating rod 172 is fully inserted within the end holder 197. When the hydraulic actuator 170 is in the engaged position, an operator is able to see that the exterior actuating rod 172 has separated from the end holder 197. Similarly, by monitoring the position of the end holder 197 with respect to the windows 192 of the stem protector 193, an operator may determine whether the mechanical actuator stem 190 has been engaged and whether the push rod 196 is fully inserted within the mechanical actuator stem 190. Indicators or markings may be added to any one or more of these components to allow the operator to determine the degree of hydraulic or mechanical actuation. Additionally, sensors may be used to detect the relative positions of these components for notifying an operator.
Ram blocks 182, 184 are engaged one at a time with the interior actuating rod 173 through a T-block connector 180 which is attached at the end of the interior actuating rod 173. The T-block connector 180 is configured to be received by each of the ram blocks 182, 184 through a T-slot 183. When the ram block carrier 160 is in the lower position, the T-block connector 180 is engaged with the T-slot 183 of the upper ram block 182, and when the ram block carrier 160 is in the upper position, the T-block connector 180 is engaged with the T-slot 183 of the lower ram block 184. Accordingly, due to the shape and size of the T-slot 183, the up and down movement of the ram block carrier 160 simply allows the T-block connector 180 to slide between the T-slots 183 of the different ram blocks 182, 184. It should be appreciated that the size of the components of the ram block carrier 160 and carrier actuating mechanisms 150, 155, 162 allow the T-block connector 180 to move to an engagement position with each T-slot 183 of the ram blocks 182, 184. Additionally, a programmable actuator may be utilized to position the T-block connector 180 within the T-slots 183 of each ram block 182, 184.
Ram block carrier 160 is configured to be in a lower position, as shown in
In an example, hydraulic fluid controlled by an operator is injected into the extend port 153 and into a cavity of the hydraulic actuator 150. This causes the actuating piston 151 to rise which in turn pushes the actuating stem 152 and the attached ram block carrier 160 into the upward position shown in
Hydraulic fluid which operates the hydraulic actuator 150 of the ram block carrier 160, and hydraulic fluid which operates the hydraulic actuator 170 of the ram blocks 182, 184 may be stored in a hydraulic panel which is formed within or outside the blowout preventer 100. Additionally, control of the hydraulic actuators 150, 170 may be operated manually by an operator, or may be operated according to a programmable control unit and in response to sensors which detect conditions of the carrier 160 and ram blocks 182, 184. For example, a sensor may detect that a ram block 182 is in a worn condition and programmable control unit may operate hydraulic actuator 150 to move the ram block carrier 160 into the upward position.
Ram block carrier 160 is configured to be in a lower position, as shown in
Referring to the examples illustrated in
The rotation of the pinion 155 is controlled by the twisting or rotation of the pin 156. Rotating the pin 156 in one direction causes it to move in one direction against the rack 162 and causes the carrier 160 to move up. Rotating the pin 156 in another direction causes it to move in another direction against the rack 162 and causes the carrier 160 to move down. Accordingly, indicators may be added on the outside of the pin 156 or the pin retractor 157 which allow an operator to monitor the rotational position of the pin 156 to determine the position of the pinion 155 with respect to the rack 162 and the overall position of the ram block carrier 160. Additionally, sensors may detect the rotation of the pin 156 for notifying an operator.
In an example, pin 156 may be rotated manually by an operator using a wrench or automatically. Pin 156 may be rotated using a number of different machines or tools which are known to a person having ordinary skill in the art. For example, pin 156 may be rotated using a variety of electrical motors, hydraulic motors or other rotating devices. When the blowout preventer 100 is used in deep water situations, the mechanical actuator 156 of the ram block carrier 160 or the mechanical actuator 190 of the ram blocks 182, 184 may be operated using a remotely operated vehicle (ROV). The ROV could be used to supply hydraulic fluid to operate a motor or could be used to directly rotate the mechanical actuators 156, 190.
Referring to
Still referring to
Additionally, the covering member 241 includes a threaded hole 247 for receiving a threaded screw 248 extending from the bottom plate 243 through the top plate 242 and into the threaded hole 247. In this example, a flange 246 is placed between the covering member 241 and the top plate 242. For example, a user may rotate the covering member 241 thereby unscrewing the threaded hole 247 from the threaded screw 248, and allowing an opening within the top plate 242 to be exposed. This allows inspecting of the interior of the blowout preventer 200 and releasing pressure build up within the blowout preventer 200.
One of skill in the art will recognize that the described examples are not limited to any particular size. Further one of skill in the art will recognize that the blowout preventer 100, 200 is not limited to any type of material. As a non-limiting example, the blowout preventer 100, 200 is formed primarily from low alloy steel. In another example, metal components utilized in manufacture, when possible and not restricted by pressure constraints or other operational reasons, may be 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 which can range in operation from 3,000 psi to 20,000 psi. In an example, a housing of the blowout preventer 100, 200 may be machined and ram block carriers may be cast; however, a number of manufacturing techniques may be used such as the machining or casting of any component of the blowout preventer 100, 200.
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.
