Battery operated autonomous scale removal system for wells

Abstract

An autonomously operated well intervention tool system includes a lubricator sealingly affixable to an upper end of a well. The lubricator has a latch at an upper end thereof. A well intervention tool system is releasably matable with the latch. The well intervention tool system comprises a wellbore intervention device at a longitudinal end thereof. The lubricator has at least one isolation valve to close fluid communication between the well and the lubricator.

What is claimed is: 
     
         1 . An autonomously operated well intervention tool system, comprising:
 a lubricator sealingly affixable to an upper end of a well, the lubricator comprising a latch at an upper end thereof;   a well intervention tool system releasably matable with the latch, the well intervention tool system comprising a wellbore intervention device at a longitudinal end thereof; and   wherein the lubricator comprises at least one isolation valve to close fluid communication between the well and the lubricator.   
     
     
         2 . The system of  claim 1  wherein the latch comprises an electrical connector to enable supply of electrical power to the well intervention tool system. 
     
     
         3 . The system of  claim 1  wherein an electrical connector is located anywhere within the lubricator system. 
     
     
         4 . The system of  claim 1  wherein the wellbore intervention device comprises a scale removal device. 
     
     
         5 . The system of  claim 1  wherein the wellbore intervention device comprises at least one of a production logging instrument and a plug or packer setting tool. 
     
     
         6 . The system of  claim 1  wherein the well intervention tool system comprises at least one swab cup on an exterior surface thereof to enable lifting the well intervention tool system by upward movement of fluid in the well. 
     
     
         7 . The system of  claim 1  wherein the well intervention tool system comprises a powered propulsion unit to enable movement of the well intervention tool system along an interior of the well. 
     
     
         8 . The system of  claim 1  wherein the lubricator comprises at least one equalization valve in a fluid communication line extending between the well and the lubricator. 
     
     
         9 . The system of  claim 1  wherein the lubricator comprises at least one pressure relief valve configured to selectively vent pressure inside the lubricator. 
     
     
         10 . The system of  claim 1  wherein the scale removal device comprises at least one of a chemical storage and release mechanism, motor-rotated blades, motor-rotated abrasive mills, an electric shock discharge device, an acoustic device and a heater. 
     
     
         11 . The system of  claim 1  wherein the well intervention tool system comprises means for automatically stopping the well intervention tool system at a selected position in the well. 
     
     
         12 . A method for performing intervention operations in a well, comprising:
 latching a well intervention tool system in a lubricator, the lubricator comprising at least one isolation valve at a well connection end thereof, the lubricator comprising at least one pressure equalization valve, the lubricator comprising at least one pressure relief valve;   closing the at least one isolation valve;   affixing the lubricator to an upper end of a well;   opening the at least one pressure equalization valve to impart pressure in the well to an interior of the lubricator;   opening the at least one isolation valve;   releasing the well intervention tool system to move into the well to selected depth therein;   operating a wellbore intervention device on the well intervention tool system; and   returning the well intervention tool system to the lubricator.   
     
     
         13 . The method of  claim 12  wherein the returning the well intervention tool system to the lubricator comprises lifting the well intervention tool system using flow of fluid in the well. 
     
     
         14 . The method of  claim 12  wherein the returning the well intervention tool system to the lubricator comprises operating a propulsion device in the well intervention tool system. 
     
     
         15 . The method of  claim 12  further comprising closing the at least one isolation valve, opening a pressure relief valve to vent pressure from within the lubricator and removing the lubricator from the well. 
     
     
         16 . The method of  claim 12  further comprising closing the at least one isolation valve, opening a pressure relief valve to vent pressure from within the lubricator, removing a sealing cap from an upper end of the lubricator and retrieving the well intervention tool system from within the lubricator. 
     
     
         17 . The method of  claim 12  further comprising attaching an electrical cable to a connector forming part of a latch used to retain the well intervention tool system in the lubricator and applying electrical power to the electrical cable to recharge at least one battery in the well intervention tool system. 
     
     
         18 . The method of  claim 12  wherein the wellbore intervention device comprises a scale removal device. 
     
     
         19 . The method of  claim 12  wherein the wellbore intervention device comprises at least one of a production logging instrument and a packer or plug setting tool.