A multilateral wellbore junction and a method for installing the junction

A multilateral wellbore junction, and method for installation, for preventing particulate entry to the flow system which comprises a thin walled sleeve 10 having a premachined window 12 which is aligned with a window 42 in the primary wellbore casing from which a lateral wellbore extends. A lateral liner 46 is disposed through the windows and into the lateral wellbore. The sleeve can be swaged into contact with the primary casing and the lateral liner can be sealed to the sl GB 2371580 A data dump probe 130 comprises a memory, a processor and a communication port for connection to a borehole logging tool 112. Data is downloaded from the logging tool and a copy is stored in the probe memory, the transfer of data being controlled by the processor. The copied data is transferred to a surface computer 118, either by physically moving the probe to the computer and connecting them via the probe's communication port, or by a radio frequency link 156. The probe ma GB 2371581 In a substructure (10) for a floating oil or gas production platform, an arrangement to tension a plurality of risers (16) extending from the sea bed up to the substructure, the arrangement comprising: a conventional hydraulic tensioner/heave compensator (17) for each riser, in which there is a soft spring formed by a piston cylinder combination acting against an accumulator, the heave compensators for the risers being disposed to compensate for vertical oscillations of rela GB 2371582 A borehole communication system for mud pulse telemetry though a compressible drilling fluid comprises: a drilling fluid source configured to supply fluid under pressure though a conduit towards a drill bit; a gas injector 84 for injecting gas into the fluid thereby rendering the fluid downstream of the injector compressible; a gas supply 82 in fluid communication with the gas injector via a gas conduit 104; a pulser in the borehole configured to generate pressure in the com GB 2371583 A levelling tool of the type used for levelling, for example, wet concrete or screed to provide a uniform and level surface finish, comprising an elongate housing (10) having a first straight edge (21) adapted to be placed on and moved across the surface to the levelled, and two or more telescopically extending beams (14, 15) contained within the housing (10) and extendible therefrom as required to select an extended overall length for the tool. Ad