“The present invention relates to valves typically used on downhole tools in oil and gas wells and in particular, though not exclusively, to a water injection valve.”
“A suitable valve design comprises a body including a seat against which a poppet or other closing surface of the valve can rest. The poppet is biased towards the seat(s) to hold the valve in a closed position. Water passed down the tubing string of a well bore will arrive at the poppet, and the water pressure will work against the loading of the spring and force the poppet away from the seat. The water is then directed through ports in the poppet, whereupon it takes a convoluted path to return to a central path through the valve and exit at its base.”
“Such valves have a number of disadvantages. Typically these valves have a spring which applies a load to the poppet to keep the valve closed. Thus when water flows an initial pressure will open the valve, but there is a tendency for the valve to close again as the pressure drops when the fluid is flowing through the valve. A further disadvantage of these valves is in the arrangement of the ports through which the water flows when the valve is open. By the nature of the design, these ports are typically small in diameter and as such they increase the pressure drop through the valve. The convoluted narrow path also causes erosional problems through the valve and increases the potential debris build up in the valve which can cause the valve to fail.”
“It is an object of at least one embodiment of the present invention to provide a valve that overcomes at least some of the disadvantages of prior art valves. It is a further object of at least one embodiment of the present invention to provide a water injection valve having a high bypass flow area. A yet further object of at least one embodiment of the present invention is to provide a water injection valve which is a high lift valve.”
“According to a first aspect of the present invention there is provided a valve….”
“By creating a direct flowpath from the inlet to the outside of the valve through the ports, which is unimpeded, that is the cross-sectional area of the flow path is not reduced, the problems associated with a pressure drop through the valve are alleviated.”
“Preferably the ports are arranged circumferentially on the tubular body. More preferably, a cross-sectional area of the ports is greater than half the total surface area of the tubular body. In a preferred embodiment there are two substantially rectangular ports located on the tubular body. The ports are arranged such that they take up a substantial portion of the tubular body to provide for maximum flow through of fluid when the valve is open. In the preferred embodiment portions of the tubular body between the ports provide longtitudinally arranged rails.”
“Embodiments of the invention will now be described, by way of example only, with reference to the accompanying figures in which: Fig 1 is a part cut-away cross-sectional view through a valve according to an embodiment of the present invention, shown in a (a) open and (b) closed configuration; Figs 2 [sic] illustrate a schematic view of the arrangement of the flow housing on the valve of Fig 1 wherein Fig 2(a) is rotated by ninety degrees with respect to Fig 2(b); Fig 3 is a cross-sectional view of a valve according to a further embodiment, wherein the left-hand side of the figure illustrates the valve in the open configuration and the right-hand side illustrates the valve in the closed configuration;…”
“Referring initially to Fig 1 of the drawings, there is illustrated a valve, generally indicated by reference numeral 10, according to a first embodiment of the present invention. Fig 1(a) is the valve 10 in an open configuration, while Fig 1(b) is the valve 10 in a closed configuration…. Valve 10 comprises a top sub 12 including a boxed section 14 for connecting the valve 10 to an anchoring device, i.e. a lock or packer. Typically the valve is made up to an [sic] wireline lock or retrievable bridge plug and run to depth, usually in the packer tail pipe. Top sub 12 contains a bore 106. Bore 106 is the inlet to the valve 10 so that fluid passed down the work string can input the valve.”
“Fig 2(a) provides a side view of the housing 18, while Fig 2(b) shows the same housing rotated by 90 degrees. Flow housing 18 comprises a tubular body 130 which has a diameter less than or equal to the diameter of the top sub 12. Oppositely arranged on the body 130 are two slots or ports 132. The ports 132 are arranged longtitudinally and cover a substantial portion of the valve 10, beginning at the top sub 12 and ending near the end cap 24. Ports 132 are substantially rectangular in cross-section, having a rounded portion 134 toward the end cap 24. The ports 134 [it is common ground that that is a mistaken reference – it should be 132] may be of any chosen dimensions but must provide a cross-sectional area that is greater than the cross-sectional area of the bore 106. Preferably the cross-sectional area of the ports is approximately an order of magnitude greater than the cross-sectional area of the bore 106. The shape in this embodiment is as a consequence of milling through a cylinder formed on a slope. Together the ports 132 remove a substantial portion of the body 130 to provide maximum flow of fluid through the valve 10. Portions of the body 30 remaining to either side of the ports 132 provide rails 136 used to help guide the poppet 84 through the valve without impeding its path. Thus it can be seen from Fig 2(a) that the poppet 84 and poppet skirt 68 are substantially exposed within the body 130. This cut-away to flow housing 18 results in the valve 10 having a high bypass flow area which minimises the pressure drop and erosion problems through the valve 10. This additionally reduce the debris build up potential as there are less surfaces, ledges or other surface areas which the flow path impinges on where debris could collect.”
“Reference is now made to Fig 3 of the drawings which illustrates a valve, generally indicated by reference 100, according to a second embodiment of the present invention…. Fig 3 illustrates the valve 100 enclosed (right-hand side) and open (left-hand side) configurations.”
“Returning to Fig 3, there is illustrated a poppet skirt 68. Poppet skirt 68 is threaded to the recess 88 on the poppet 84. The skirt 68 provides a streamlined profile running back to the threads 64 which attaches to the collet 109. Such a profile of the nose 104 together with the skirt 68 provides a streamlined flow passage 120 to maximise fluid flow through the valve in the open position. This is further enhanced by the design of the flow housing 18 located around the inner tube 34. This housing 188 is illustrated in Fig 2 and is described hereinbefore with reference to the Figure. In this way the relationship between the cross-sectional area of the flow path at the bore 106 is smaller than the cross-sectional area through the ports 132 as they are open. This cut-away to flow housing 18 results in the valve 100 having a high bypass flow area which [sic] negligible pressure drop and minimises erosion problems through the valve 100. This additionally reduced the debris build up potential.”
“The principle [sic] advantage of the present invention is that it provides a valve having a high bypass flow area with a smooth flow path which minimises pressure drop and erosion problems through the valve while also reducing debris build up potential in the valve. Reduction flow is thus optimised and is only restricted by the bore of the anchoring device. It will be appreciated by those skilled in the art that modifications may be made to the invention herein without departing from the scope thereof. Additionally though a poppet is shown, any suitable arrangement of two sealing surfaces could be used. Yet further the size and number of the ports in the flow housing may be changed to vary the flow rate through the valve, while maintaining the desired relationship between the cross-sectional areas.”
“and create an unimpeded flow path between the inlet and the ports with negligible pressure drop”
“Construction, whether of a patent or any other document, is of course not directly concerned with what the author meant to say. There is no window into the mind of the patentee or the author of any other document. Construction is objective in the sense that it is concerned with what a reasonable person to whom the utterance was addressed would have understood the author to be using the words to mean. Notice, however, that it is not, as is sometimes said, ‘the meaning of the words the author used’, but rather what the notional addressee would have understood the author to mean by using those words. The meaning of words is a matter of convention, governed by rules, which can be found in dictionaries and grammars. What the author would be understood to mean by using those words is not simply a matter of rules. It is highly sensitive to the context of and background to the particular utterance. It depends not only upon the words the author has chosen but also upon the identity of the audience he is taken to have been addressing and the knowledge and assumptions which one attributes to that audience.”
“By creating a direct flowpath from the inlet to the outside of the valve through the ports, which is unimpeded, that is the cross-sectional area of the flow path is not reduced, the problems associated with a pressure drop through the valve are alleviated.”
“communicating with a work string providing a flow path of a first cross-sectional area.”
“(a) if an invention to which the application in suit relates is supported by matter disclosed in the earlier relevant application or applications, the priority date of that invention shall instead of being the date of filing the application in suit be the date of filing the relevant application in which the matter was disclosed...”
“The approach is not formulaic: priority is a question about technical disclosure, explicit or implicit. Is there enough in the priority document to give the skilled man essentially the same information as forms the subject of the claim and enables him to work the invention in accordance with that claim?”
“Yet further the size and number of ports in the flow housing may be changed to vary the flow rate through the valve.”
“… the matter relied upon as prior art must disclose subject-matter which, if performed, would necessarily result in an infringement of the patent.”
“284. Mr Meade submitted that it was not a legitimate attack simply to cast about in the common general knowledge, using hindsight to find disparate elements which, if assembled in the way disclosed by the patent in suit, would fall within the claims. One can perfectly well have an invention in a new assembly of known elements providing a new benefit, and many good inventions are just that. I agree.”
“In the case of standard textbooks, it is likely that all or most of the main text will be common general knowledge. In many cases common general knowledge will include or be reflected in readily available trade literature which a man in the art would be expected to have at his elbow and regard as basic reliable information.”
“I cannot see any significant differentiator between this and the valves here in front of me [viz the Red Spider and Omega valves]. They have all the same principal ingredients. It is a poppet; it is a spring; it is separately mounted and it has big windows; it has a replaceable seat; it has a connection which allowed it to be fit a packer or a bridge plug.”
“213(1) Design right is a property right which subsists in accordance with this Part in an original design. (2) In this Part ‘design’ means the design of any aspect of the shape or configuration (whether internal or external) of the whole of part of an article. (3) Design right does not subsist in – (a) a method or principle of construction. ….. (4) A design is not ‘original’ for the purposes of this Part if it is commonplace in the design field in question at the time of its creation. …. (6) Design right does not subsist unless and until the design has been recorded in a design document or an article has been made to the design.”
“Design right is infringed by a person who without the licence of the design right owner does, or authorises another to do, anything which by virtue of this section is the exclusive right of the design right owner.”
“226(1) The owner of design right in a design has the exclusive right to reproduce the design for commercial purposes – (a) by making articles to that design …. (2) Reproduction of a design by making articles to the design means copying the design so as to produce articles exactly or substantially to that design, and references in this Part to making articles to a design shall be construed accordingly.” (a) by making articles to that design …. (2) Reproduction of a design by making articles to the design means copying the design so as to produce articles exactly or substantially to that design, and references in this Part to making articles to a design shall be construed accordingly.”
“we have no customer for but ‘would be nice to do’. The Omega ethos has always been to be different and not to copy products but to ‘create a market’ with our own tools. In this way, we establish a divide between ourselves and our competitors. Presently, we have moved slightly to counter emerging competition from Caledyne, Red Spider and others. This means that we have to look at the offerings from these companies and if possible provide something superior.” 131. No. 3 on the list was “Injection Valve”, and was followed by the sentence: “Present injection valves appear to have a poor track record. Problems are leaks back through the valve when shut, vibration causing valves to ‘drop off’ and vibration affecting plug connection.”