In technical terms, a fish can be any object which has been lost or stuck in a borehole, and has a serious negative impact on well operations. Fishes can be anything, whether that is a drill string that has come away, a bit cone, or even a hand tool that has been inadvertently dropped into the well. To solve this issue, fishing involves the use of special tools and procedures to recover the fish and allow drilling to continue. While this article will deal solely with regular fishing, there is also an alternative method, which involves using through-tubing processes that make use of tools on a wireline or coiled tubing.
Virtually any object that is dropped into a well, or even run into it, may need to be fished out at some point. Furthermore, the need for fishing may arise at any given point during operations, and there are therefore a wide range of different tools and methods. There are three main technologies that these solutions are built around, though: pulling, milling, or cutting the pipe itself, and other downhole parts.
A fishing job is one option, but this will depend on the cost and likelihood of success. Other options include:
- Leaving the fish where it is, and sidetracking or redrilling the well to follow an alternative path
- Leaving the fish where it is, and completing the well in a shallower zone
- Abandoning the well altogether
Preferably, the fish should be completely avoided in the first place, thanks to the right planning and proper drilling practices. However, it is important that a contingency plan is in place should the situation arise. Continue reading
