Armored optical fiber cable

An armored optical well logging cable comprising:

• a substantially non-deformable and round central core element having an outer diameter of about 0.120 inches, said central core element comprising a plurality of optical fibers embedded in elastomer and coated with a hard, resilient material;
• eight substantially round and insulated solid conductor strands wound around and contacting said central core with a right hand lay and about a 3.5-inch lay length and a diameter of about 0.071 inches such that the outer diameter of said central core element and said conductor strands is about 0.262 inches;
• sixteen substantially round inner armor wires 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 wires being fabricated in the same operation, wherein said central core element, said conductor strands and said inner armor wires form a central bundle having an outer diameter of about 0.368 inches;
• and
• twenty four substantially round outer armor wires of glavanized steel wire wound around and contacting said inner armor wires in a left hand lay with a 3.5-inch lay length, said outer armor wires having a diameter of about 0.049 inches such that the total cable diameter has an outside diameter of about 0.469 inches and said inner and outer armor wires are substantially torque balanced.

A process of forming an armored optical fiber cable comprising:

• applying a central core element;
• winding conductor elements helically around said central core elment, 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 an earth formation surrounding a well bore wherein one end of an optical fiber 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 to the transmitter/receiver during the lowering and raising of the instrument in the well bore, the improvement comprising:

• transmitting said data through an armored optical fiber cable which comprises:
• a substantially non-deformable center core element;
• at least six substantially solid elements helically wound around said central element in a given handedness;
• at least twice the number of said at least six elements of inner armor wires wound around and contacting said at least six elements of the same handedness in a unilay helical configuration, said at least six elements and said inner armor wires being fabricated around said central core element at the same time wherein the elements and the wires of the same handedness and the central core form a central bundle, said central bundle containing at least one jacketed optical fiber;
• 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 torque exerted by said inner armor wires and said outer armor wires are 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 core containing at least one optical fiber;
• 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 core formed to be substantially non-deformable across the cross-section thereof;
• a 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;
• at least one optical fiber in said central bundle extending substantially the length of said cable;
• 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.