Downhole time domain reflectometry with optical components

摘要

A disclosed system for downhole time domain reflectometry (TDR) includes a surface electro-optical interface, a downhole electro-optical interface, a fiber-optic cable that couples the surface electro-optical interface and the downhole electro-optical interface, and an electrical transmission line that extends from the downhole electro-optical interface into a wellbore environment to enable TDR operations. A described method for downhole TDR includes transmitting an optical signal to a downhole environment, converting the optical signal to an electrical signal in the downhole environment, reflecting the electrical signal using an electrical transmission line in the downhole environment, analyzing data corresponding to the reflected electrical signal, and displaying a result of the analysis.

主权项

1. A downhole time domain reflectometry (TDR) system, the system comprising:
a surface electro-optical interface; a downhole electro-optical interface; a fiber-optic cable that is deployed in a borehole and that couples the surface electro-optical interface and the downhole electro-optical interface; an electrical transmission line that extends from the downhole electro-optical interface into a region of interest with one or more formation fluids that contact the electrical transmission line; and a data analysis unit coupled to the surface electro-optical interface, wherein the data analysis unit is configured to analyze TDR interrogation response signals to recover electromagnetic profile information regarding the one or more formation fluids, wherein the TDR interrogation response signals are obtained by using the downhole electro-optical interface to convert a TDR interrogation signal from an optical signal conveyed by the fiber-optic cable to an electrical signal conveyed by the electrical transmission line, and to convert a TDR interrogation response signal from a reflected electrical signal conveyed by the electrical transmission to a corresponding optical signal conveyed by the fiber-optic cable.