Armored cable containing a hermetically sealed tube incorporating an optical fiber

An armored optical well logging cable comprising:

• a central substantially round hermetically sealed tube core having an outer diameter of between about 0.110 to about 0.120 inches, and an inner diameter of about 0.06 inches, said core including therein a plurality of optical fibers embedded in an elastomer, said core formed from two metal sections joined longitudinally together around said fibers and forming a cylindrical tube, said tube exhibiting a yield strain greater than about 0.85;
• eight substantially round and insulated solid conductor strands wound around said central core with a right hand lay and about a 3.5 inch lay length and a diameter of 0.071 inches such that the outer diameter of the central core and the conductor strands is about 0.262 inches;
• sixteen substantially round inner armor strands of galvanized steel wire having an outer diameter of about 0.058 inches wound around and contacting said conductor strands in the same handedness and lay length as said conductor strands, said conductor strands and said inner armor being fabricating in the same operation, wherein said central core, said conductor strands and said inner armor wires from a central bundle having an outer diameter of about 0.368 inches;
• and
• twenty-four substantially round outer strands of galvanized steel wire wound around and contacting said sixteen inner strands in a let hand lay with a 3.5 inch lay length, said twenty-four strands having a diameter of about 0.049 inches such that the total cable diameter has an outside diameter of about 0.469 inches.

A process of forming an armored optical fiber cable comprising:

• rolling at least two annealed metal wires into sections, said sections capable of fitting together to form a cylindrical tube central core having an inner diameter sufficient to accept at least one or a plurality of buffered optical fibers;
• forming said central core around said buffered optical fibers from the rolled sections;
• joining hermetically said sections into said tube central core;
• winding conductor elements helically around said tube central core, said winding is of a given handedness and lay length;
• winding a layer of inner armor wires of the same handedness as said conductor elements and with the same lay length and applied at the same time as said conductor elements helically around said conductor elements;
• and
• fabricating a layer of outer armor wires of opposite handedness to said layer of inner armor wires and with such a lay length that the torques extended by said inner and outer armor are substantially balanced when the cable is under tension.

In a method of well logging to obtain data about earth formations surrounding a wellbore wherein one end of an optical fiber cable is connected to a surface transmitter/receiver and the end opposite thereto is connected to an instrument for measuring and transmitting data about the earth formations through said optical fiber cable to the transmitter/receiver during the lowering and raising of the instrument in the wellbore, the improvement comprising:

• transmitting said data through an armored optical fiber cable which comprises;
• a central hermetically sealed tube core including one or a plurality of buffered optical fibers, said core formed from at least two metal sections joined hermetically together around said inner core and forming a cylindrical tube, sections hermetically wherein said metal sections were preshaped by rolling from an annealed wire, and wherein said tube exhibits a yield strain of greater than 0.85;
• at least six substantially solid elements wound helically around said tube in a given handedness;
• at least twice the number of said at least six solid elements of inner armor wires wound around and contacting said at least six solid elements with the same handedness in a unilay helical configuration, said at least six solid elements and said inner armor wires being fabricated around said tube at the same time wherein the elements and the wires of the same handedness and the tube form a central bundle;
• and a plurality of outer armor wires contacting said inner armor wires, said outer armor wires wound in an opposite helical handedness to the handedness of said inner armor wires such that the torques exerted by said inner armor wires and said outer armor wires substantially balanced;
• and
• transmitting electrical power or signals through said at least six elements.

An armored optical fiber cable suitable for use in an environment which subjects said cable to repeated longitudinal elongation and relaxation forces, said cable comprising:

• a central hermetically sealed tube core, said core comprising at least two metal sections fitting together around one or a plurality of buffered optical fibers and forming said core, wherein said metal sections were preshaped by rolling from an anealed wire, and wherein said metal sections and the tube formed therefrom are fabricated from metals which exhibit a yield strain greater than about 0.85;
• a plurality of insulated conductor elements wound helically around said central core in a given handedness and lay length;
• a plurality of inner armor wires wound around and substantially continuously contacting adjacent insulated conductor elements, said inner armor wires having the same handedness and lay length as said insulated conductor elements;
• and
• a plurality of torque balancing outer armor wires wound around said outer armor wires in an opposite helical handedness to the handedness of said inner armor wires.

An armored optical fiber cable suitable for use in well logging which subjects said cable to repeated longitudinal elongation and relaxation forces, said cable comprising:

• a central hermetically sealed tube core, said core comprising at least two metal sections fitting together around one buffered optical fiber of a plurality of helically wound buffered optical fibers and forming said core, wherein said metal sections were preshaped by rolling from an anealed wire, and wherein said metal sections and the tube formed therefrom are fabricated from metals which exhibits a yield strain greater than about 0.85;
• plurality of substantially solid insulated conductor elements wound helically around said central core in a given handedness and lay length, said solid insulated conductor elements being disposed in and substantially filling a first annular ring at any given cross-section along the length of said cable;
• a plurality of inner armor wires wound around said insulated conductor elements, said inner armor wires having the same handedness and lay length as said insulated conductor elements, said inner armor wires being disposed in and substantially filling a second annular ring concentric with said first annular ring at any cross-section along the length of said cable, each of said inner armor wires resting on an adjacent insulated conductor element and not in the grooves formed between adjacent insulated conductor elements to provide said cable with flexibility and to reduce friction between said insulated conductor elements and said inner armor wires, said central core, said insulated conductor elements and said inner armor wires forming a central bundle;
• and
• a plurality of torque balancing outer armor wires wound around said inner armor wires in an opposite helical handedness to the handedness of said inner armor wires, said outer armor wires being disposed in and substantially filling a third annular ring generally concentric with said second annular ring at any given cross-section along the length of said cable.