Signal pressure pulse generator

Apparatus for use in a pipe string having a bore suspended in a well and conducting a fluid stream along said pipe bore, said apparatus producing a time distributed series of fluid pressure change signals in said fluid stream in response to signals from a downhole instrument for detection at the surface, the apparatus comprising:

• (a) a housing with means at one end for fluid tight connection to an upwardly continuing portion of said pipe string and means at the other end for fluid tight connected to a downwardly continuing portion of said pipe string, and fluid channel means therein to conduct said fluid stream between said portions of said pipe string;
• (b) a fluid powered turbine in said housing arranged to receive at least part of said fluid stream to produce a rotational effort output;
• (c) a rotary valve means rotationally connected to said turbine with at least one fluid channel arranged to pass at least part of said fluid stream and to variably resist the flow of said part of said fluid stream to cause at least one cycle of fluid change pressure in said stream, said cycle to proceed from a preselected maximum fluid pressure to a preselected lower minimum fluid pressure and back to said maximum fluid pressure, for each incremental turn of said valve relative to said housing;
• (d) rotational control means in said housing operably associated with said rotary valve means responsive to said signals from said downhole instrument to momentarily stop the rotation of said rotary valve means in selected rotary positions relative to positions corresponding to said preselected maximum fluid pressure, said lower minimum fluid pressure thereby generating said series of fluid pressure signals in said fluid stream.

Apparatus for use in a pipe string having a bore suspended in a well and conducting a fluid stream along said pipe bore, said apparatus producing time distributed fluid pressure change signals in the fluid stream in response to signals from a downhole instrument for detection at the surface, the apparatus comprising:

• (a) a housing having means at one end for fluid tight attachment to an upwardly continuing portion of the pipe string and means at the outer end for fluid tight attachment to a downwardly continuing portion of the pipe string and having fluid channel means for conducting said fluid stream between said portions;
• a fluid powered turbine in said housing and comprising a rotor and a fixed stator, said rotor supported for rotation relative to said stator within said housing, said rotor and stator each having a plurality of blades projecting radially therefrom defining a plurality of peripherally distributed fluid channels therebetween, said fluid channels being shaped to add peripheral velocity to said fluid flowing therethrough to provide impulse loading to drive said rotor in said rotation, said stator and said rotor channels being arranged such that in a preselected amount of rotation of said rotor with respect to said stator, said rotor and said stator channels are in streamlined registry, then move through a position of maximum interference with the flow of fluid moving through said turbine, and again are in said streamlined registry thereby producing rotary position dependent variable resistance to fluid flow through said turbine;
• (d) load means connected to said rotor to change the rotational speed of said rotor in response to signals from said downhole instrument to generate said time distributed fluid pressure change signals in said fluid stream that result from different rotational positions of said rotor relative to said stator.

Apparatus for use in a pipe string having a bore and suspended in a well and conducting a fluid stream along said pipe bore, said apparatus producing time distributed fluid pressure change signals in said fluid stream characteristic of an encoded message from a downhole instrument for detection at the surface, the apparatus comprising:

• (a) a housing having a longitudinal axis and means at one end for fluid tight attachment to an upwardly continuing portion of the pipe string and having means at the other end for fluid tight attachment to a downwardly continuing portion of the pipe string and having fluid channel means for conducting said fluid stream between said portions;
• (b) a fluid powered turbine in said housing through which at least part of said fluid passes, said turbine comprising at least one stage, each stage having one rotor and one stator, said stator being fixedly attached to said housing, said rotor situated downstream of said stator and carried by an arbor, said arbor bearingly supported for rotation about said longitudinal axis of said housing, said arbor being axially movable to vary the distance between said stator and said rotor, said rotor and said stator having salient power vanes extending therefrom and defining an annular flow path for said fluid stream therebetween, said power vanes peripherally distributed such that rotational increments of said rotor place said rotor power vanes in streamline registry with said stator vanes to produce minimum flow resistance and minimum pressure drop across said turbine, while approximately half-increments of rotor rotation place said rotor power vanes in a maximum flow interference relationship with said stator vanes to produce maximum flow interference and maximum pressure drop across said turbine;
• (c) rotation control means operably connected to said rotor and being responsive to said signals from said downhole instrument, to define rotational positions and change of said positions relative to said stator to produce said time distributed fluid pressure signals in said fluid stream characteristic of the encoded message to be transmitted to the surface.

Apparatus for use in a pipe string suspended in a well with a drilling fluid flowing through said pipe string, said apparatus generating time distributed fluid pressure signals in said drilling fluid for detection at the surface of said well in response to signals from a downhole instrument, said apparatus comprising:

• (a) an outer housing defining a central bore through which at least a portion of said drilling fluid flows;
• (b) a stator located within said central bore of said housing, said stator having a plurality of stator turbine blades projecting radially therefrom, said stator turbine blades being attached to said outer housing;
• (c) a rotor rotationally mounted within said central bore of said outer housing adjacent to said stator, said rotor having a plurality of rotor turbine blades projecting radially therefrom, said stator turbine blades and said rotor turbine blades being cooperatively arranged to urge said rotor to rotate when said drilling fluid flows through said stator turbine blades and said rotor turbine blades, said rotation of said rotor turbine blades placing said rotor turbine blades and said stator turbine blades in streamline registration with one another while further rotation of said rotor turbine blades places said rotor turbine blades and said stator turbine blades in streamline interference with one another;
• and
• (d) means responsive to said signals from said downhole instrument for releasably latching said rotor in a first position corresponding to said streamline registration and in a second position corresponding to said streamline interference, thereby generating said time distributed fluid pressure signals in said drilling fluid.