4c_Process_Offshore

The following are illustrations of Modules and Modular Systems that have been created because of current demands. One of their features is compliance with restraints which in principal they accept (larger modules always seem to demand no restraint other than a particular requirement). The supposed benifits of large scale designs is a restraint on the use of small scale designs ie the example Pipeline Pump Spread accomplished using 3
Problems of Modulerisation.
As an objective the interest of Modulerising Seperation Operation would be acheived by something very dynamic like a Hydro Cyclone which can be built from unitised process tubes. Unfortunately Good Seperation has historically been solved on the basis"Bigger is better" approach. The reasons for this is that a) for gas seperation the largest surface area, slow moving will allow the most gas to break out from the well flow, and b) the largest area , depth and again slow moving will enable the water and oil to seperate more efficiently. As each project application may have a different feed stock (well flow), different sizes and types of seperation are reqired. As previously stated the solution is usually the larger the better however this does not always suit the location or space available. Another problem concerning Floaters is the need for the Seperation process to be in a location for least movement (pitch, roll and heave) allow good seperation. This location is usually the mid point between the Bow and Stern and Port and Starboard sides of a hull.
Generally 3 sets of rotating (large scale) machines would be more efficient and reliable than 15 sets of rotating (small scale) ones. The demand for more suitable, easily, transported and short build systems encourages the questioning of the restraint to use large size machines.

If we take Seperation as a typical process and the subject of a typical module we can investigate its development. The example shown is Varg and ABB Project Managed design. The hull originates from SE Asia and the design produced a need for the module packages to meet required restraints. The hull plans are shown in detail and illustrate the need for dimensional control for the interconnection hull to modules. They also show the approach to safe areas, the segregation using blast walls of safe areas and Areas with a possible hazard . Another restraint is that the performance of Seperation need's for optimisation to suffer minimal external disorientation, it therefore neds to be at the epicentre of the point of minimal movement. Other items also need to be at the epicentre for best functioning of there activity. The Varg Swivel is of the type that can complete 270 degrees rotation, at the point of maximum rotation it can be taken to the reverse quadrant rather than go through 360 degrees rotation. Again the mooring with free rotation but following its directuional positioning to current, wave and wind can weather vane to a suitable position. When this comes to the extremes of movement, Thrusters can provide correction to take the hull to an reverse hull position 260 degrees . Hulls able to do 360 degree corection still use such capability. The example shown is Uisige Gorm stern thruster, this could assist positionining say to optimise an off loading operation without going through 360 degrees rotation on the mooring. Other retraints cover the problems of process elevation. Again such positional sensitive process operations need to be at the centre of least sensitivity. Towers are such an item. rather than concern the problems of elevation is the pressure to make the process more smaller and oftem dynamic. Dearation columns are a subject in question. The attached outlines an approch to remove this sensitivity to elevation and lack of movement. It also promotes the fact that it is easier to find a location for such a design.