Systems and methods for drilling in high temperature environments using optical fiber communication

Abstract

A drilling system includes a lower drill string and an upper drill string. The lower drill string includes a drill bit, a drive system coupled to the drill bit, at least one lower drill pipe coupled to the drive system, and a sensor system disposed in the at least one lower drill pipe. The sensor system includes one or more sensors and a first connector coupled to the one or more sensors. The upper drill string is coupled to the lower drill string and includes one or more upper drill pipes. The upper drill string also includes a MWD/LWD electronics system coupled to the one or more upper drill pipes. The MWD/LWD electronics system includes an electronics component communicatively coupled to the first connector via a fiber optic cable. The electronics component is in communication with the one or more sensors via the fiber optic cable.

What is claimed is: 
     
         1 . A method of drilling a wellbore, comprising:
 drilling a first portion of a well using a first drill string;   pulling the first drill string out of the well;   inserting a lower drill string into the well, wherein the lower drill string comprises a bottom hole assembly, a plurality of drill pipes, and a sensor system, wherein the sensor system comprises one or more sensors coupled to a first connector;   lowering a fiber optic cable into the lower drill string, wherein the fiber optic cable comprises a second connector configured to mate with the first connector;   mating the second connector with the first connector;   coupling the fiber optic cable to a MWD/LWD electronics system at an end of the fiber optic cable opposite the second connector, wherein the electronics system is a part of an upper drill string, and wherein the electronics system is in communication with the sensor system via the fiber optic cable;   coupling the upper drill string to the lower drill string forming a drill string assembly; and   drilling a second portion of the well.   
     
     
         2 . The method of  claim 1 , further comprising:
 sensing one or more conditions in the second portion of the well by the sensor system; and   transmitting one or more data signals corresponding to the one or more conditions from the sensor system to the MWD/LWD electronics system via the fiber optic cable.   
     
     
         3 . The method of  claim 1 , wherein second portion of the well is in a high temperature high pressure environment. 
     
     
         4 . The method of  claim 1 , wherein the MWD/LWD electronics system remains in the first portion of the well while drilling the second portion of the well. 
     
     
         5 . The method of  claim 1 , wherein the sensor system comprises any combination of an acoustic sensor, a pressure sensor, a temperature sensor, a resistivity sensor, a gamma ray sensor, and an inclination azimuth sensor. 
     
     
         6 . The method of  claim 1 , wherein the first connector and the second connector are wet connectors. 
     
     
         7 . A method of monitoring conditions while drilling, comprising:
 detecting one or more drilling conditions via one or more sensors;   outputting one or more data signals corresponding to the one or more detected drilling conditions, wherein the sensors are coupled to a lower drill string;   transmitting the one or more data signals from the one or more sensors to a first connector, the first connector disposed within the lower drill string;   transmitting the one or more data signals from the first connector to a second connector, the second connector coupled to the first connector; and   transmitting the one or more data signals from the second connector to a MWD/LWD electronics system via a fiber optic cable, the electronics system disposed in an upper drill string.   
     
     
         8 . The method of  claim 7 , further comprising:
 converting, by a processor in the electronics system, the one or more data signals into one or more mud pulse signals; and   transmitting the one or more mud pulse signals to a receiver.   
     
     
         9 . The method of  claim 7 , wherein the lower drill string and the one or more sensors is disposed within a high temperature high pressure zone of a well. 
     
     
         10 . The method of  claim 8 , wherein the upper drill string and the MWD/LWD electronics system remains out of the high temperature high pressure zone. 
     
     
         11 . The method of  claim 7 , wherein the one or more sensors are rated to function properly in environments having temperatures up to 500° F. 
     
     
         12 . The method of  claim 11 , wherein the one or more sensors comprise any combination of an acoustic sensor, a pressure sensor, a temperature sensor, a resistivity sensor, a gamma ray sensor, and an inclination azimuth sensor. 
     
     
         13 . The method of  claim 11 , wherein the fiber optic cable comprises a plurality of distinct fiber optic channels, and is configured to carry a plurality of distinct data signals. 
     
     
         14 . The method of  claim 11 , comprising:
 detecting conditions of a high temperature high pressure well zone from outside of the high temperature high pressure well zone via the one or more sensors disposed within the high temperature high pressure well zone.   
     
     
         15 . A drilling system with fiber optic communication, comprising:
 a lower drill string comprising:
 a drill bit; 
 a drive system coupled to the drill bit; 
 at least one lower drill pipe coupled to the drive system; 
 a sensor system disposed in the at least one lower drill pipe, the sensor system comprising one or more sensors and a first connector coupled to the one or more sensors; and 
   an upper drill string coupled to the lower drill string, the upper drill string comprising:
 one or more upper drill pipes, and 
 a MWD/LWD electronics system coupled to the one or more upper drill pipes, the MWD/LWD electronics system comprising an electronics component, wherein the electronics component is communicatively coupled to the first connector via a fiber optic cable, wherein the electronics component is in communication with the one or more sensors via the fiber optic cable. 
   
     
     
         16 . The drilling system of  claim 15 , wherein the one or more sensors are rated to function properly in an environment having temperatures up to 500°. 
     
     
         17 . The drilling system of  claim 15 , wherein the one or more sensors comprise any combination of an acoustic sensor, a pressure sensor, a temperature sensor, a resistivity sensor, a gamma ray sensor, and an inclination azimuth sensor. 
     
     
         18 . The drilling system of  claim 15 , wherein the first connector and the second connector are centrally disposed within the lower drill string. 
     
     
         19 . The drilling system of  claim 15 , wherein the fiber optic cable comprises a plurality of distinct fiber optic channels, and is configured to carry a plurality of distinct data signals. 
     
     
         20 . The drilling system of  claim 15 , wherein the upper drill string and the MWD/LWD electronics system remains out of a high temperature high pressure well zone while the lower drill string and sensor system are in the high temperature high pressure well zone.