Well surveying instrument and method

[5. Method according to claim 1, wherein said

• radiant energy is acoustic energy.] 6. Method [according to claim 5, including] of investigating the size and shape characteristics of a subsurface earth cavity, or the like, penetrated by a borehole, comprising the steps of
• establishing a radiant acoustic energy source in said cavity at a selected location on the vertical axis of said borehole,
• projecting radiant acoustic energy during a substantially continuous scan from said source into said cavity at a plurality of selected angles between about 0.degree. and about 180.degree. from said vertical axis, such that the acoustic energy is directed at selected portions of the walls and roof of the cavity including those portions adjacent the borehole;
• rotating said source about said vertical axis of said borehole, and receiving reflected acoustic energy. 7. Method according to claim [5] 6 including orienting said generating point with respect to
• north.

[14. Apparatus according to claim 13 including means for rotating said upper

• section about the axis of said borehole.] 15. Apparatus [according to claim 12, wherein] for investigating the character of a subsurface earth cavity, or the like, penetrated by a borehole, comprising
• an instrument having an intermediate section swivelly connected for horizontal rotation and an elongated lower section pivotally connected with said intermediate section of said instrument for movement in a plane transverse to the horizontal,
• a source of radiant energy in said lower section, said energy source [includes] including acoustic energy generating means for producing a beam of acoustic energy, and receiving means in said instrument, said receiving means [includes] including means in said lower section for
• sensing reflected acoustic energy. 16. Apparatus according to claim 15, wherein
• said beam is directed along a path coincident with the longitudinal axis of
• said lower section. 17. Apparatus according to claim 15, wherein said beam is directed along a path angularly intersecting the longitudinal axis of
• said lower section. 18. Apparatus according to claim 15, including means
• for rotating said upper section about the axis of said borehole. 19. Apparatus according to claim 18, including orienting means for
• controlling said rotating means as a function of north. 20. Apparatus according to claim 18, including orienting means for controlling said rotating means as a function of north.

[23. Apparatus according to claim 22, including orienting means for controlling said

• rotating means as a function of north.] 24. Apparatus for investigating the character of a subsurface earth cavity, or the like, penetrated by a borehole, comprising
• an instrument having an intermediate section swivelly connected for horizontal rotation and an elongated lower section pivotally connected with said intermediate section of said instrument for movement in a plane transverse to the horizontal,
• means in said lower section for radiating energy therefrom toward the cavity in a plurality of directions, and
• receiving means in said instrument for detecting radiant energy. 25. Method of investigating the character of a subsurface earth cavity, or the like, penetrated by a borehole, comprising
• establishing a pivot point in said cavity at a selected location on the vertical axis of said borehole,
• establishing a generating point pivotally movable in said cavity relative said pivot point,
• projecting radioactive energy into said cavity from said generating point by discharging a discrete quantity of radioactive flotation material from said generating point into said cavity, and
• sensing radiations emanating from said discharged material. 26. Method according to claim 24, wherein said borehole is lined by a casing extending from said borehole into said cavity, and
• said radioactive material floats upward in said cavity about the exterior
• surface of said casing. 27. Apparatus for investigating the character of a subsurface earth cavity, or the like, penetrated by a borehole, comprising
• an instrument having an elongated lower section pivotally connected with an upper section of said instrument,
• means for rotating said upper section about the axis of the borehole,
• a source of radiant energy in said lower section, said energy source including means for discharging a discrete quantity of radiation flotation material into said cavity, and
• receiving means in said instrument for detecting radiant energy including
• means for sensing radiations. 28. Apparatus for investigating the character of a subsurface earth cavity, or the like, penetrated by a borehole, comprising
• an instrument having an elongated lower section pivotally connected with an upper section of said instrument,
• means for rotating said upper section about the axis of the borehole,
• a source of radiant energy in said lower section, said energy source including acoustic energy generating means for producing a beam of acoustic energy,
• receiving means in said instrument for detecting radiant energy including means in said lower section for sensing reflected acoustic energy, and
• means for positioning said lower section, at selected angles with respect
• to the longitudinal axis of said upper section. 29. Apparatus for investigating the character of a subsurface earth cavity, or the like, penetrated by a borehole, comprising
• an instrument having an elongated lower section pivotally connected with an upper section of said instrument,
• means for rotating said upper section about the axis of the borehole,
• a source of radiant energy in said lower section, said energy source penetrating an output of light rays,
• receiving means in said instrument for detecting radiant energy including a camera responsive to said light rays, and
• orienting means for controlling said rotating means as a function of north.

An apparatus for investigating the size and shape characteristics of a subsurface earth cavity penetrated by a borehole comprising

• an instrument having an intermediate section and an elongated lower section, said instrument being capable of being lowered through the borehole so that said intermediate section thereof at least partially enters the cavity,
• said intermediate section being swivelly supported for rotation about an axis which is generally parallel with the borehole axis;
• means for pivotally connecting said lower section to said intermediate section so that said lower section is pivotable in generally vertical planes relative to said intermediate section about a generally horizontal axis;
• drive means for pivoting said lower section relative to said intermediate section;
• at least one acoustic energy generating means in said lower section for transmitting acoustic energy in a direction generally perpendicular to the longitudinal axis of said lower section toward wall and roof portions of the cavity as said lower section is pivoted about said generally horizontal axis;
• and
• means in said lower section for receiving reflected acoustic energy, whereby said instrument can be selectively rotated and said lower section pivoted to direct acoustic energy toward, and receive reflected acoustic energy from, substantially all portions of said cavity.