Skip to content

Home > Model Components > BOP Stack > Bottom Connections

Bottom connections

The Bottom Connection tab allows to create and specify all bottom connections properties. Each line must be connected to a spool block given specific properties.

You may create spool blocks by pressing the Create New Spool Block button on the bottom right corner of the window. Spool blocks can also be deleted if needed by pressing the Delete Spool Block button which will remove the active row from the grid.

Warning

Spool blocks are not actually used in the computations, therefore a local frame of reference will be defined. The following assumption must be satisfied : the flexible pipe must have its End_1 end node connected to the bottom connection (defined by spool block and its Alpha, Beta angles) and its End_2 end node connected to the top (defined by Flexjoint and its angles K,L). The azimuth angle is Beta. The elevation is Alpha.

Each spool block is characterized by the following parameters :

  • Coordinates (x,y,z) of bottom part of a spool block. These coordinates are defined in the local frame of the BOP stack. These coordinates define the position of the connection at the bottom of the spool block.

  • Elevation Angle (Alpha angle) of the spool block. This angle is the angle with Ox around Oz.

  • Orientation Angle (Beta angle)

  • Diameter : this diameter will be used to display the spool block in the 3D View window when the 3D lines display option is activated.

  • Length L1 : see Figure below.

  • Length L2 : see Figure below.

The spool block is located in a plane, which is parallel to the axis of the whole BOP stack. The L1 segment is parallel to the Z axis in the local frame of the BOP stack.

The spool block is characterized by two angles :

  • An intrinsic angle when the spool block is fabricated: angle alpha on the previous drawing

  • An orientation of the spool block: which indicates in which direction the length L2 points towards when the end node of the line is connected to the bottom connection: this angle (Beta) has to be defined and we can use a similar convention as for the top orientation (angle K): it is the angle the spool block makes with the local main axis defined by connecting the origin (X=0, Y=0) and the bottom connection (X,Y)

Note

A spool block has only one connection point located at the end of L2 segment. There is no connection allowed at the location of the change of direction. The spool block is just a bent rigid piece of pipe.

If both lengths are zero, no spool block will display and the flexible line will be directly connected to the bottom connection. Otherwise a spool block has to be drawn: two piece of rigid pipe of the same diameter.