Stripping (Live-Well Operations)

Key Takeaways

• Stripper assembly operation provides the dynamic pressure seal during stripping operations — the typical stripper includes an elastomer seal element designed to conform to the pipe surface as it passes through, providing the pressure-tight dynamic seal needed for live-well operations; the stripper element is typically rated for specific pressure levels (typical 5,000-10,000 psi working pressure for routine applications, higher pressures for HPHT applications) and specific pipe sizes (with the stripper being matched to the specific pipe being stripped); the stripper is typically supplemented by grease injection (for higher pressures) or specialty seal arrangements (for unusual conditions); the integrated stripping seal supports the reliable pressure containment that live-well operations require.
• Coiled tubing stripping operations are the most common application — coiled tubing operations are typically performed on live wells (because the operations including acid stimulation, scale removal, sand cleanout, etc. are performed on producing wells without first killing the well), with the coiled tubing being stripped through the wellhead lubricator and stripper assembly during deployment and retrieval; the coiled tubing operations include continuous stripping (the tubing moving continuously through the stripper) rather than the joint-by-joint movement of conventional tubing strings, with the resulting operational simplicity supporting efficient operations; the integrated coiled tubing equipment includes the stripper as part of the operational infrastructure.
• Snubbing operations support stripping with substantial axial force application — snubbing equipment includes hydraulic rams that push pipe down against wellhead pressure (the snubbing force) and pull pipe up while balancing the wellhead pressure-induced ejection force; the snubbing operation supports stripping under conditions where the routine stripping force is inadequate (typically when wellhead pressure is high enough that the natural pressure-induced force on the pipe exceeds the operational pulling capability); modern snubbing equipment supports stripping operations across the operational range encountered in live-well intervention, with specialty equipment for HPHT and other demanding applications.
• Operational considerations for stripping include continuous stripper monitoring (the seal condition must be monitored throughout the operation, with progressive seal wear potentially requiring grease injection adjustment or stripper replacement), pipe condition monitoring (the pipe surface condition affects the stripper performance, with damaged or corroded pipe potentially compromising the seal), and integration with pressure-control systems (the various pressure-control elements must work together as an integrated system); modern operational protocols include systematic monitoring and maintenance of the stripping equipment that supports reliable operations across the diverse operational conditions encountered.
• Modern stripping technology supports the diverse live-well intervention operations across modern petroleum operations — major service companies (Halliburton, Schlumberger, Baker Hughes, specialty intervention contractors) provide comprehensive stripping equipment and services that support the operational requirements; the continued evolution of stripping technology supports increasingly sophisticated live-well operations including HPHT applications, sour service applications, and various specialty operations; the integrated technology supports the operational flexibility that live-well intervention requires across the modern oil and gas industry.