Abstract: A radio-active tracer, carried by a pressurized gas, is injected through an axially displaceable tube into a flow stream of steam within a well tubing string to perform a steam injection survey of underground formations intersected by a well bore into which the tubing string extends. The injection tube is guided for displacement from a retracted position at an acute angle to the flow stream direction to an injection position within the tubing string through a riser port, swab valve and steam inlet connection located below a storage zone within a lubricator pipe from which a logging tool is inserted into the tubing string.

Abstract: A cylindrical high temperature logging tool assembly supended from the shield of a coaxial cable for insertion into the interior of a well bore. To isolate the instruments contained within the interior of the cylindrical assembly from the fluids or steam within the well bore, and to facilitate assembly, the cylindrical oil tool comprises a plurality of axially aligned segments including a grease holding cavity at the end thereof wherein a quantity of non-conducting grease is packed and is compressed therein by the threadable engagement of the sections. Since most greases are generally incompressible, the threaded assembly provides a technique by which the grease pressure level within the housing can be achieved which are greater than the pressure head within the well bore. In this manner an integral structure is provided which can be deployed at various depths within the well bore and which furthermore provides selective arrangement of sections to arrange the requisite instrumentation for well bore logging.