Internal Repair of Pipeline Leaks Using Pressure-Activated Sealant

Abstract

Abstract A cost-effective method of internally repairing pipeline leaks has been developed that - in many instances - eliminates the need for expensive and risky external mechanical repairs. By delivering a pressure-activated sealant between two pigs to a leak site and pressure activating the sealant to polymerize as a flexible solid within the leak path, it is possible to internally repair pipeline leaks without the need for excavating or replacing defective sections with minor leaks. Introduction According to Department of Transportation's Office of Pipeline Safety, there are over 326,000 miles of natural gas transmission pipelines and over 1,923,000 miles of natural gas distribution pipelines presently in the United States. With natural gas consumption projected to increase by 50% over the next seventeen years, a major focus will be placed on pipeline integrity management, particularly pipe and joint leak repair systems. The conventional methods of curing pipeline leaks is to either perform an external mechanical repair of the leak or install an internal patch or sleeve that reduces the inside diameter of the pipe. What is needed is a cost-effective method of internally repairing the pipeline leaks without the need for expensive and risky external mechanical repairs. The paper will describe the use of a pressure-activated sealant technology to effect internal repair of pipeline leaks. This sealant technology has been successfully applied in the oil and gas industry for nine years, including offshore gathering lines and pipeline applications. These upstream industry case histories will be outlined. The described technology is unique in that a differential pressure through the leak site activates a polymerization process that solidifies the liquid sealant and seals the leak paths. The availability of this technology can result in a significant reduction in the long-term risks and economics of repairing pipeline leaks. Pursuant to a Cooperative Agreement with the United States Department of Energy (DOE) - Office of Fossil Energy - National Energy Technology Laboratory - Strategic Center for Natural Gas - Delivery Reliability Program, Seal-Tite is extending the capabilities of the pressure-activated sealant technology to cure leaks in natural gas distribution and transmission systems. Preliminary results of the DOE project will be available for the Eastern Regional Meeting. The DOE section of the paper will review:leak data used as a benchmark to develop new sealant formulas and procedures, andlaboratory leak sealant operations on simulated pipeline leaks. The DOE Project has not been completed. A status report on the project will be distributed at the Conference.