Customized Subsea Production Flowline Cleanout with Coiled Tubing from aFloating Production Storage and Offloading Vessel

摘要

The recovery of a pipeline inspection gauge(PIG)left in a subsea production flowline in an unknownlocation after a failed cleaning and inspection operation is discussed.Combined with paraffin deposits,theproduction flowline of the best offshore producer in northeast Brazil was completely blocked.Extensive planning was necessary to spot the coiled tubing(CT)equipment to accommodate the deckconfiguration of the floating production storage and offloading(FPSO)vessel and to overcome dimensionaland load capacity limitations.A customized extendable jacking frame was manufactured to support the CTinjector and provide room for a work window.This fit-for-purpose rigging was necessary to enable theviability of the cleanout in the production flowline of the well.CT operation modeling software was used toanalyze the hydraulic and force simulations to verify that the CT would reach the target depth with optimaljetting efficiency and would tailor the cleanout methodology.Paraffin was successfully cleaned from the flowline,and the PIG was released and recovered on surface.The CT was efficiently and safely rigged up on a FPSO without any nonproductive time or service qualityissues.The versatility of CT services to not only deliver intervention services on conventional wells but to alsoadapt to rig up in extreme geometries and environments are showcased along with how CT services canbe applied to flowline interventions.For this case,a customized CT frame was manufactured to overcome the challenges of rigging up on avessel with extremely limited deck space and load capacities and restoring hydrocarbon production aftera failed PIG procedure.