Subsea is a well-known term used to refer to equipment, methods and technology used at underwater locations, and particularly at locations on or close to the seabed for various applications, and in particular to explore, drill and develop oil and gas fields that exist below the ocean floors. The ocean floor or seabed at which subsea apparatus is used may be at a relatively shallow location (shallow in this context being at depths less than 1,000 feet) or at a deep water location (generally meaning water depths in the range 1,000 to 10,000 feet, or even deeper).
It will be appreciated that a wide variety of types of subsea apparatus (equipment) is used in such applications. This variety includes subsea apparatus providing a control function (for example comprising controllable valves to regulate the flow of fluids to or from a well) and subsea apparatus providing a connection function (such as providing an electrical or optical control or monitoring link between two pieces of apparatus, or providing a fluid conduit from one subsea location to another, for example to convey fluids to a well for injection into that well, or to convey production fluids from a well). A term commonly used to refer to one type of such subsea interconnecting apparatus is “umbilical”, and a subsea umbilical will typically comprise a flexible intermediate portion containing at least one electrical cable, optical wave guide, or fluid conduit, with connection means provided generally at each end for connecting the umbilical to other apparatus. For example, umbilicals are known which comprise a plurality of electrical conductors (e.g. wires or cables) with a corresponding plurality of electrical contacts provided in connectors at each end of the umbilical. There are circumstances in which such an umbilical, or indeed another piece of subsea apparatus, is conveyed to a subsea (underwater) location (this operation is also referred to in the art as “deploying” the apparatus) and is required to remain at that location for some time before it is installed (i.e. connected to some other piece of subsea equipment). For example, an umbilical for providing fluid, electrical and perhaps optical connection to a well head may first be laid on the seabed (deployed). Then, an end of the umbilical may be placed into a mechanical receptacle on the well head to provide the fluid connection (and in this condition the umbilical is partially installed). In certain known arrangements the electrical and/or optical connection between the umbilical and well head is provided by connecting another piece of subsea apparatus, known as a “jumper”, between a connector on the umbilical and a corresponding connector on the well head. Thus the jumper is another form of subsea interconnect apparatus or device, typical shorter than apparatus referred to as umbilicals, but similarly providing an interconnecting function. When the jumper is connected, the umbilical is then fully installed to the well head. Clearly, although a subsea umbilical or other subsea apparatus can be tested before it is deployed (i.e. before it is conveyed to its subsea location), degradation or damage to it may occur while it is being transported to its deployment location and indeed while it is waiting at that location before installation occurs. For example, if the connectors of subsea apparatus are not protected in some way at the subsea location before installation, then they can in general become contaminated with silt or other material, and any electrical contacts they contain could suffer corrosion. Such degradation is problematic. One attempt to solve these problems has been to fit a so-called “dummy” connector to the connector of subsea apparatus such as an umbilical, the dummy connector mating with the apparatus's connector in the same way as would a corresponding connector of apparatus to which the umbilical is to be connected. Certain known arrangements are such that when the connector and dummy connector are mated at least one seal is made which prevents or at least inhibits the ingress of contaminants into the mated arrangement and prevents seawater from making contact with any electrical contact of the umbilical's connector. Certain dummy connectors are adapted to provide protection to other parts of the connection interface (i.e. not just to electrical contacts). The dummy connector typically remains mated with the connector of the subsea apparatus until shortly before that apparatus is to be installed. The dummy connector is then detached and the subsea apparatus is connected in the required configuration. Although this technique offers some advantages, there is still the possibility that the subsea apparatus could have been damaged or degraded in some way while the dummy connector was in place. For example, although the dummy connector may have protected the connector of an umbilical, the umbilical may have suffered damage elsewhere along its length whilst in situ or waiting for deployment. Only after removal of the dummy connector, and connection of the umbilical to other subsea apparatus may this damage or degradation become apparent, when a problem is detected with the operation of the subsea system as a whole.
It is therefore an object of certain embodiments of the invention to provide subsea assemblies, subsea test apparatus and methods of handling subsea apparatus which overcome, at least partially, one or more of the problems associated with the prior art.