A system for controlling subterranean slurry circulating velocities and pressures when using a wall to urge slurry and to place an apparatus within or to extend a passageway through subterranean strata, the system comprising: a conduit assembly comprising at least one slurry passageway apparatus member, and conduit string members comprising a first conduit string member, and at least one larger diameter additional conduit string member, wherein said first conduit string member comprises a bore and extends longitudinally through a proximal region of said passageway through subterranean strata and defines an internal passageway member through the bore, wherein said at least one larger diameter additional conduit string member extends longitudinally through said proximal region of said passageway through subterranean strata and protrudes axially downward from an outermost protective conduit string lining said proximal region, thereby defining a first annular passageway member between a wall thereof and a surrounding wall of a subterranean passageway, wherein said first conduit string member extends at least partially within a first end and a second end of said at least one larger diameter additional conduit string member to define an intermediate enlarged internal passageway member, at least one additional annular passageway member, or combinations thereof, and wherein said at least one slurry passageway apparatus member connects said first conduit string member to said at least one larger diameter additional conduit string member, said at least one slurry passageway apparatus member comprising at least one radially-extending passageway member communicating between said internal passageway member, said intermediate enlarged internal passageway member, said at least one additional annular passageway member, said first annular passageway member, or combinations thereof, such that fluid slurry flowing at least in one of said passageway members (53, 54, 54A, 55) is diverted through said at least one radially-extending passageway member to another of said passageway members (53,54, 54A, 55) to, in use, control subterranean slurry circulating velocities and pressure to place the apparatus within or to extend said passageway through subterranean strata. a conduit assembly comprising at least one slurry passageway apparatus member, and conduit string members comprising a first conduit string member, and at least one larger diameter additional conduit string member, wherein said first conduit string member comprises a bore and extends longitudinally through a proximal region of said passageway through subterranean strata and defines an internal passageway member through the bore, wherein said at least one larger diameter additional conduit string member extends longitudinally through said proximal region of said passageway through subterranean strata and protrudes axially downward from an outermost protective conduit string lining said proximal region, thereby defining a first annular passageway member between a wall thereof and a surrounding wall of a subterranean passageway, wherein said first conduit string member extends at least partially within a first end and a second end of said at least one larger diameter additional conduit string member to define an intermediate enlarged internal passageway member, at least one additional annular passageway member, or combinations thereof, and wherein said at least one slurry passageway apparatus member connects said first conduit string member to said at least one larger diameter additional conduit string member, said at least one slurry passageway apparatus member comprising at least one radially-extending passageway member communicating between said internal passageway member, said intermediate enlarged internal passageway member, said at least one additional annular passageway member, said first annular passageway member, or combinations thereof, such that fluid slurry flowing at least in one of said passageway members (53, 54, 54A, 55) is diverted through said at least one radially-extending passageway member to another of said passageway members (53,54, 54A, 55) to, in use, control subterranean slurry circulating velocities and pressure to place the apparatus within or to extend said passageway through subterranean strata.