A New Rigless Approach for Fishing a Stuck and Parted Coiled Tubing in a Live Well

Abstract

Usually, the preferred way to restore production in wells with accessibility heavily compromised is by rig workover activity. However, a preliminary approach in rigless mode followed by rig activity can be even more effective in the presence of several critical issues. Here we illustrate the methodology and technical solutions adopted to perform a challenging rigless fishing job to make the subsequent rig workover operation quicker, cheaper, and safer.

A workflow was developed for a course of actions to perform a complex fishing intervention while fully respecting the well control requirements. Considering the well status—1½-in. coiled tubing (CT) stuck in 4½-in. tubing at 7582 ft due to scale buildup, parted in two segments side by side, top of fish at 1345 ft and with no injectivity in the well—it was decided to adopt a fit-for-purpose rigless strategy by combining conventional fishing tools (flow release overshot, continuous cutting overshot) with a CT anchor, which guided the electrical line (EL) cutting tools inside the pipe while keeping it in tension. To accomplish the target, a robust design, with multiple contingency plans was properly defined and successfully implemented. In addition to the main constraint of having a CT pipe parted and stuck in the tubing, the scale deposit prohibited killing the well by bullheading. Consequently, the overall fishing operations were planned and managed as if the well was alive.

The alternate use of CT fishing tools, CT anchor, and EL cutting operations allowed recovering approximately 6958 ft over a total length of 7398 ft, leaving just 440 ft of CT pipe stuck in hole inside the scale deposit (with the new top of fish at 7142 ft). As a result, a complex well situation, which could have led to a long and expensive rig operation, was successfully approached in rigless mode, leaving the well ready for a simpler workover activity.

The use of Continuous Cutting Overshot (CCO), through a standard "cut & drop" approach, was limited by the CT lubricator height. An innovative fishing approach was then deployed: a proper CT anchor BHA, to latch and hang the CT pipe in the tubing wall, was run. The beveled shape of the CT anchor allowed EL tools to enter inside the CT pipe and cut the same above the free point, so recovering longer sections of pipe.