Optical Interface System For Communicating With A Downhole Tool

Abstract

An optical interface system is disclosed. In accordance with an embodiment, such a system includes an optical interface. A surface control system is coupled to a first end of the optical interface, and a logging tool coupled to an opposite second end of the optical interface. Data and/or power can be exchanged between the logging tool and the optical interface by converting electrical signals into corresponding optical signals which can be transmitted over the optical interface. Corresponding methods are also disclosed herein.

What is claimed is: 
     
         1 . A system comprising:
 an optical interface;   a surface control system coupled to a first end of the optical interface; and   a logging tool coupled to a second end of the optical interface, the first and second ends being opposite ends of the optical interface;   wherein data is exchanged between the surface control system and the downhole tool using optical signals sent over the optical interface.   
     
     
         2 . The system of  claim 1 , wherein the surface control system comprises a surface interface module having a first converter configured to convert electrical signals into corresponding optical signals for transmission over the optical interface and to convert optical signals received via the optical interface into corresponding electrical signals; and
 wherein the logging tool comprises a second converter configured to convert electrical signals into corresponding optical signals for transmission over the optical interface and to convert optical signals received via the optical interface into corresponding electrical signals.   
     
     
         3 . The system of  claim 2 , wherein the logging tool comprises an adapter that mates with a read-out port on the logging tool, wherein the second converter is located in the adapter and the adapter is coupled to the second end of the optical interface. 
     
     
         4 . The system of  claim 2 , wherein the surface interface module comprises a photonic power module configured to deliver power to the logging tool as an optical signal. 
     
     
         5 . The system of  claim 4 , wherein the logging tool comprises a photovoltaic power converter that converts the optical signal produced by the photonic power module into electrical power. 
     
     
         6 . The system of  claim 5 , wherein the logging tool comprises an adapter that mates with a read-out port on the logging tool, wherein the photovoltaic power converter is located in the adapter and the adapter is coupled to the second end of the optical interface. 
     
     
         7 . The system of  claim 4 , wherein the optical interface comprises a fiber-optic cable comprising at least one optical fiber. 
     
     
         8 . The system of  claim 7 , wherein optical signals corresponding to the power and the data are transmitted over the same optical fiber using different optical wavelengths. 
     
     
         9 . The system of  claim 7 , wherein optical signals corresponding to the power and the data are transmitted over first and second optical fibers, respectively, of the fiber-optic cable. 
     
     
         10 . The system of  claim 4 , wherein optical signals corresponding to the data are sent over multiple optical fibers of the fiber-optic cable in parallel, with each optical fiber representing a respective data channel. 
     
     
         11 . The system of  claim 1 , comprising an external power source that supplies power to the logging tool. 
     
     
         12 . The system of  claim 1 , comprising an internal power source that supplies power to the logging tool. 
     
     
         13 . The system of  claim 1 , wherein the data is exchanged between the surface control system and the downhole tool using the optical interface at a transfer rate of at least 1 gbps. 
     
     
         14 . The system of  claim 1 , wherein the data is exchanged between the surface control system and the downhole tool using the optical interface at a transfer rate of at least 57.6 kbps. 
     
     
         14 . The system of  claim 1 , wherein the downhole tool is not deployed in a borehole. 
     
     
         15 . The system of  claim 1 , wherein the downhole tool comprises at least one of a logging-while-drilling tool, a measurement-while-drilling tool, a sampling tool, a wireline logging tool, or a slickline logging tool. 
     
     
         16 . The system of  claim 1 , wherein the downhole tool comprises a memory storing log data, and wherein the exchange of data between the surface control system and the downhole tool comprises the transmitting log data stored in the memory of the downhole tool to the surface control system over the optical interface using the optical signals. 
     
     
         17 . The system of  claim 1 , wherein the data exchanged between the surface control system and the downhole tool comprises at least one of diagnostic data, calibration data, software updates, or initialization data. 
     
     
         18 . The system of  claim 16 , wherein the initialization data comprises at least one of instructions for synchronizing a clock of the logging tool to a clock of the surface control system, instructions for selection of measurement points and/or types, or instructions for selection of data compression parameters. 
     
     
         19 . A method comprising:
 establishing an optical interface between a surface control system and a downhole tool located at a surface location; and   exchanging data between the downhole tool and the surface control system using a first optical signal sent over the optical interface.   
     
     
         20 . The method of  claim 19 , comprising delivering power from the surface control system to the downhole tool using a second optical signal sent over the optical interface. 
     
     
         21 . The method of  claim 19 , wherein establishing the optical interface further comprises connecting a fiber-optic cable between the surface control system and the downhole tool. 
     
     
         22 . The method of  claim 20 , wherein delivering power from the surface control system to the downhole tool comprises using a photonic power module of the surface control system to generate the second optical signal. 
     
     
         23 . The method of  claim 19 , wherein delivering power from the surface control system to the downhole tool comprises using a plurality of photonic power modules each configured to generate a respective optical signal, wherein the combined energy of the respective optical signal represents the power delivered by the surface control module.