Fiber Optic Slickline and Tractor System

Abstract

A system for delivering a fiber optic slickline through a deviated well with a battery powered tractor. The system includes a tractor having an efficiency rating of at least about 30% so as to adequately serve as a conveyance aid without the requirement of surface supplied power. For example, regulating of drive sections of the tractor may take place through a hydraulic section. Thus, arms of the tractor may be hydraulically locked in an open position without the requirement of continuous power to maintain the arms in an open position. At the same time, however, the hydraulic section may include accumulator capacity so as to allow for temporary responsive collapse of the arms for sake of navigating a restriction in the well.

We claim: 
     
         1 . A system comprising:
 a tractor for disposal in a deviated well; and   a fiber optic slickline coupled to said tractor.   
     
     
         2 . The system of  claim 1  wherein said tractor comprises a downhole power source to operate the tractor. 
     
     
         3 . The system of  claim 1  wherein said fiber optic slickline is configured to obtaining measurements from the well. 
     
     
         4 . The system of  claim 1  wherein said fiber optic slickline is configured to control movement of said tractor through the well. 
     
     
         5 . A fiber optic slickline tractor assembly for disposal in a well, the assembly comprising:
 a main body;   a battery housed by said main body;   a drive section incorporated into said main body to obtain power from said battery for moving the assembly within a deviated section of the well; and   a hydraulic section coupled to said main body for directing engagement with a wall of the well for the moving of the assembly, the directing of the engagement in a manner conserving power available from said battery.   
     
     
         6 . The assembly of  claim 5  wherein wherein said battery is of a stackable configuration to allow coupling of an additional battery thereto. 
     
     
         7 . The assembly of  claim 5  wherein the drive section comprises one of a wheeled tractor and a reciprocating tractor. 
     
     
         8 . The assembly of  claim 7  wherein said drive section comprises:
 an arm for extending to a position away from said main body to attain the engaging with the well wall; 
 a roller coupled to said arm and for interfacing a wall of the well during the extending of said arm; and 
 a motor poweringly coupled to said roller through said arm to rotate said roller during the interfacing with the wall to aid in the moving of the assembly. 
 
     
     
         9 . The assembly of  claim 5  wherein the fiber optic slickline is configured to conduct signals between a surface of the well and the tractor assembly to direct the engagement of the tractor and thereby control movement of said tractor through the well. 
     
     
         10 . The assembly of  claim 8  wherein said hydraulic section comprises a locking mechanism to secure said arm in the extended position during the moving of the assembly. 
     
     
         11 . The assembly of  claim 10  wherein said hydraulic section comprises an accumulator to allow a degree of collapse by said arm from the extended position upon encountering a predetermined level of resistance. 
     
     
         12 . The assembly of  claim 7  wherein said drive section is a first drive section, the assembly further comprising a second drive section incorporated into said main body to obtain power from said battery for moving the assembly within the deviated section. 
     
     
         13 . The assembly of  claim 12  wherein said arm is a first arm of said first drive section, the assembly further comprising a second arm of said second drive section for extending to a position away from said main body in a manner substantially perpendicular to said first arm as an aid to centralization of the assembly within the well. 
     
     
         14 . A method of performing a distributed measurement survey application in a well, the method comprising:
 deploying a fiber optic slickline and tractor system into a well; and   taking measurement readings within the well via the fiber optic slickline.   
     
     
         15 . The method of  claim 14  further comprising performing another application in the well with a service tool coupled to the system. 
     
     
         16 . The method of  claim 14  wherein the distributed measurement survey application is directed at one of temperature, pressure, strain and vibration measurements. 
     
     
         17 . The method of  claim 14  further comprising using a downhole battery of the system to power said tractor system. 
     
     
         18 . The method of  claim 14  wherein the tractor system comprises one of a wheeled tractor and a reciprocating tractor. 
     
     
         19 . The method of  claim 18  wherein deploying comprises deploying a tractor system comprising at least one drive section, the drive section comprising at least one element configured to engage with the wall of the well and further comprising compensatingly collapsing the element to a degree upon encountering a predetermined amount of resistive force presented by a restriction in the well. 
     
     
         20 . The method of  claim 18  further comprising removing the system from the well by one of:
 powering the tractor in a reverse direction; and 
 pulling on the slickline from a location at an oilfield surface adjacent the well.