Patent Application
20070289637
Embodiments of the present invention will now be described, by way of example only, with reference to the attached Figures, wherein:
Generally, the present invention provides a system for securing handwheel-actuated valves at oil and gas wellheads to prevent tampering and information theft therefrom. Specifically, the invention provides wheel engagement members for engaging individual valve wheels in close proximity at a wellhead, wherein two or more engagement members may be locked together to limit operation of respective handwheel-actuated valves.
Applicant's corresponding Canadian application CA 2,555,668 (the contents of which are incorporated herein by reference) describes a system for securing wellhead equipment, including a flexible cable for wrapping about wellhead equipment. The cable is secured with a cable restraint to prevent removal of the cable and tampering with wellhead equipment. The aforementioned system also includes device shields for shielding access to specific types of wellhead equipment, wherein the device shields are secured in place with the flexible cable and cable restraint. The present application describes additional devices for use in securing wellhead valve handwheels, which may also be used in conjunction with the earlier-described securing system.
The wheel engagement members of the present invention engage a portion of a handwheel-actuated valve. At least two engagement members are used at any one wellhead such that two valves become dependently engaged. When locked together, the engagement members may not be removed or adjusted, limiting operation of the associated valves. It is preferable that when the engagement members are locked together, with or without use of a distance adjustment member (as will be described below), the handwheels become inoperable or difficult to operate. In addition, the handwheels may be locked upon their respective valve stems to prevent unauthorized removal therefrom. It should be noted that different applications and wellhead locations may require different security measures, and appropriate devices may be selected and affixed to appropriate valves at a wellhead in accordance with the invention, in a manner determined by the site engineer or security manager.
The engagement members, when properly used, secure the position of each valve handwheel. The engagement members may physically contact the rim or spokes of a handwheel to interfere with wheel rotation, or the members may be affixed to the valve stem over the handwheel to prevent removal of the handwheel, thereby engaging the handwheel against the valve stem. Once two handwheels are so engaged by the engagement members of the present invention and the engagement members are locked together, operation of the valve limited, either by substantially preventing rotation of the handwheel, or by creating a physical barrier that interferes with rotation of the handwheel such that operation of the valve is difficult or laborious.
In the embodiment of the invention shown in
In use, as shown in
In an alternate embodiment, as shown in
In use, two wellhead handwheels in relative proximity are selected for locking together using the engagement members 40. The securing nut is removed from the first handwheel, and the threaded end 42 of an engagement member 40 is threaded onto the valve stem with the extending portion 43 of the engagement member 40 protruding outwardly over the first handwheel towards the second handwheel. A separate engagement member 40 is similarly applied to the second handwheel. If the extending portions 43 of the engagement members 40 overlap, the engagement members 40 may be locked together by inserting a padlock or cable through the locking aperture 45 of each member 10. Alternatively, as shown in
In an embodiment, the extending portion 43 of the engagement members 40 protrudes above the handwheel rim, while a distance adjustment member may extend between the handwheels below the handwheel rims. The distance adjustment member is then connected to the engagement members using a large padlock or cable placed inside the handwheel rim between the handwheel spokes. Such a connection will secure the handwheels upon respective valve stems while further creating a barrier between the spokes of each handwheel, thus limiting rotation of the handwheels and also preventing unauthorized valve access.
The distance adjustment member shown in
Other suitable engagement members may be designed, constructed, and used in accordance with the invention. For example, the distance adjustment member may be a telescopic rod for connection to each engagement member, or a cable for threading through locking apertures in each engagement member.
As the purpose of the distance adjustment member is to lock a first engagement member with a second engagement member to limit movement of the engagement members with respect to their engaged valves, it is preferable that the distance adjustment member be constructed of rigid material such as steel. Although the distance adjustment member is used primarily when the extending portions of the first and second engagement members do not overlap, it may also be used when the extending portions of the engagement members do overlap, adding strength to the system.
Notably, when the engagement members each include an angled portion and threaded end, as shown in
The above security devices are preferably formed by welding together pieces of steel. Preferably, the devices are formed from steel lengths that are 1½″ wide and ⅜″ thick, although a multitude of other suitable dimensions may be used, as will be readily appreciated by those skilled in the art. It is contemplated that the devices may be custom built on-site, however it is generally not recommended to do so as specific regulations are typically imposed upon drilling and production sites to minimize the potential for hazardous occurrences. Generally, devices that may produce significant heat or sparks are therefore not permitted at wellhead locations.
Although the security devices described herein remain subject to removal by an oil scout or vandal by cutting steel, cable or padlocks, the devices provide a valuable deterrent against oil scouts, as such tampering would be immediately evident to the site engineer on daily inspection of the wellhead, and appropriate security detail could be implemented to prevent further tampering or to apprehend trespassers. Moreover, in the event of an oil or gas leak or explosion, the company owning the wellhead equipment would have evidence to indicate that appropriate security measures were in place, and to confirm that vandalism, and not negligence, caused the incident.
An embodiment of a method for securing a wellhead includes providing the valve handwheel engagement members with or without distance adjustment members to a user desirous of securing handwheel-actuated valves at a wellhead.
It should be noted that the present system of locking equipment at a wellhead provides a significant degree of flexibility to the user. For example, virtually any two handwheel-actuated valves at a single wellhead may be secured in accordance with the invention, using an appropriate number of distance adjustment members and padlocks and/or cables. Moreover, if each set of devices is locked with a separately keyed padlock, selective access to each set of valves may be provided to specific individuals simply by providing these individuals with an appropriate set of keys. A customized access system may also be implemented, in which the site engineer has a master key to lock up the entire wellhead, while flow testers may be given a key which only opens the padlock securing the flow valves.
It should be noted that although the present description refers to the use of padlocks to secure each device, many other locking mechanisms could be used to secure each device, including electronic keying, biometric verification, smartcards, or keypad access to each device.
In an embodiment of the invention, a kit is provided for securing wellhead equipment at a wellhead. The kit minimally includes two engagement members. It is contemplated that the user may desire to secure two handwheels using different types of engagement members. For example, the user may secure one handwheel with a hook-type engagement member, and the other with a threaded end-type engagement member. The user may or may not require distance adjustment members. Moreover, the user may secure the same set of handwheels with both types of engagement members to further secure the handwheel and valve. For example, the hook-type engagement member may be used to prevent rotation of the handwheel, while the threaded engagement member may be used to prevent removal of the handwheel. Accordingly, in a preferred embodiment of a wellhead securing kit, at least two of each type of engagement member are provided, as well as at least one distance adjustment member. The kit may also include lengths of cable and padlocks, as well as instructions for using the above items in securing wellhead equipment.
The above-described embodiments of the present invention are intended to be examples only. Alterations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the scope of the invention, which is defined solely by the claims appended hereto.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2550793 | Jun 2006 | CA | national |
| 2555668 | Aug 2006 | CA | national |
