pitch over the length of the screen assembly mounted over each joint 32 is a jacket 42 as shown in fig2 at least one of the shunt tubes 34 36 38 and 40 has an exit 44 under jacket 42 it also has an entrance 46 under jacket 42 flow coming downhole through tube 34 exits and goes in three directions represented by arrows 46 48 and 50 arrow 46 shows the gravel exiting above the jacket 42 arrow 48 shows the gravel exiting below the jacket 42 and arrow 50 shows the gravel re entering tube 34 under jacket 42 jacket 42 provides a jumper path for each other tube such as tubes 36 and 40 shown in fig2 jacket 42 can have a discrete path for an individual tube or it can provide a common manifold so that flow from a variety of tubes can mix within the jacket and exit a different tube from the tube that a particular flow entered the jacket 42 at the next joint 52 a different tube 38 is open for flow in three possible directions as indicated by arrows 54 56 and 58 in between joints 32 and 52 at least one tube such as 40 has open ends 60 and 62 to allow flow out from under open coupling 64 flow can go out above coupling 64 as indicated by arrows 66 and out below as indicated by arrows 68 between joints such as 32 and 52 a single tube may have one or more couplings 64 alternatively more than one tube can have.