Deployment of One of Its Kind Slim Coiled Tubing Tractor to OvercomeReach Issue in Extended Reach Restricted Smart Completed Wells

摘要

Several extended reach-restricted completion-smart wells required matrix acid stimulation using CoiledTubing (CT). These wells are equipped with Mechanical Formation Isolation Valve (MFIV) in the tubingend which needs to be reopened by using CT to access mother-bore for performing acid job. CT simulationresults for these wells showed coil can reach only 60-70% of open hole interval. Calibrated frictioncoefficients were used in CT simulation based on the data base developed from other wells in the samearea. Only CT-Tractor simulation showed 100% reach with maximum tractor over pull of 3200 lbs fromthe lock-up depth. World’s slimmest CT tractor was developed in collaboration specifically to address the challenges ofextending CT reach past lock-up depth during acidizing and other intervention jobs in minimum restrictionextended reach well. The world’s slimmest tractor (2 1/8” outside diameter; OD) was able to providea pulling force of 3200 lbs and was powered by intervention fluid pumped through coiled tubing. Thetractor has many failsafe features and self-cleaning mechanism of gripper arms to overcome the challengesencountered while tractoring in open hole. Four smart wells (with minimum restriction 2.81”) were successfully matrix acid stimulated while theCT-Tractor combination were able to extend the reach of CT beyond lock-up depth. CT-Tractor was run-in-hole (RIH) to lock-up depth and then tractor was activated from that depth to extend the reach of CT. At totaldepth (TD), the tractor was isolated and de-activated by dropping steel ball. The wells were acid stimulatedwhile pulling-out-of-hole (POH). Pre-flush was pumped while RIH at low pumping rate to avoid activatingtractor before lock-up depth and after lock-up, pre-flush was pumped through tractor to activate the tractor. This paper outlines the tractor characteristics, matrix acid stimulation jobs design parameters, detailedoperational data captured and the learning curve achieved during job execution.