Sooner or later the hole swallows something. A rod string crystallizes and parts on the upstroke. A tubing joint backs off and drops. A packer that set beautifully in 2009 refuses to release in 2026. A wireline tool hangs up, the line breaks, and now there's a fish with a bird's nest of cable on top of it. Fishing is the trade that gets it all back, and it's the most craft-heavy corner of workover work: you can't see the fish, you work it by feel and printout from thousands of feet away, and every run either improves the situation or complicates it. The old hands say fishing is a game of patience played against your own AFE, and they're right on both counts.
Know your fish
Rule one: never run a catch tool at a fish you haven't identified. The well file says what should be down there, the weight indicator and tally say where the top ought to be, and the impression block confirms it, a soft-faced block set down on the fish that comes back with a print of the top: a clean tubing collar, a ragged break, a rod pin lying against the casing wall. That print picks the tool. Guessing picks the tool too, sometimes, and that's how a fish that one overshot would have caught ends up drilled over, flared, and welded to the casing by someone's impatience. The state of the fish's top is the whole game plan.
The toolbox
Catch tools grab outside or inside. The overshot is the workhorse: it slips over the top of the fish and its grapple, spiral or basket, bites the OD harder the harder you pull, with releasing versions so the crew can let go of a fish that won't come. The spear does the same trick from the inside, entering the fish's bore and expanding to grip the ID, the answer when the outside is inaccessible or ragged. Rod fishing has its own family of overshots and sockets sized for sucker rods and their couplings, because parted rods, corkscrewed by compression, are the most common fish in pumping country.
Around the catch tools works the supporting cast. Jars and accelerators deliver hammer blows uphole or down to break a stuck fish's grip; bumper subs let the string strike down with control. Washover pipe, large-bore pipe with a rotary shoe on bottom, drills over the outside of a fish that's stuck by cement, scale, or packed sand, freeing the grip before the catch. Junk baskets and powerful magnets sweep up the small hard stuff, bit cones, slips, hand tools, that mills would otherwise fight. Mills themselves grind up what won't come whole, packers especially. And for pipe stuck deep, the wireline free-point tool measures where the string is actually held, so a back-off, an internal cut, or a chemical cut can recover everything above the stuck point and turn one long fish into a shorter, honest one.
Working the job
A fishing job runs as a loop: diagnose, run, work the fish, evaluate, decide. Each trip adds information, the print, the torque, what came back in the basket, and the good fisherman updates the plan every round instead of repeating the last run louder. Circulation stays part of the craft, too: cleaning fill off the top of the fish before catching it, and keeping the hole clean so today's fish doesn't get buried into next week's. Well control never leaves the table, since a well that swallowed tubing is still a well, with everything the hydrostatic arithmetic implies while pipe is moving in and out of it.
The arithmetic of quitting
Fishing's hardest tool is the calculator. The classic rule of thumb weighs the value of the fish plus the value of the hole below it against the rig's daily cost times the days you're prepared to spend, discounted by odds that shrink with every failed run. The discipline is setting that number, the fishing budget, before the first tool goes in the hole, because mid-job is the worst place to make an economic decision: every crew on location wants one more run, and one more run is how ten-day fishing jobs happen to three-day fish. When the budget's spent, the alternatives get their turn: plug back above the fish and complete uphole, sidetrack around it where the well justifies drilling, or, on a well near the end of its life, let the fish stay and fold it into the P&A program. Some fish are cheaper to abandon than to admire.
Common questions
Can wireline be fished?
Yes, with respect: broken cable balls up into a bird's nest that ordinary catch tools push aside. Rope spears and side-door overshots are built for it, working the cable first, then the tool below. The worst move is running heavy tools blind into a nest and packing it solid.
What makes a fish "stuck" versus just dropped?
A dropped fish sits free and catches easily; a stuck one is held, by packed sand or scale, by cement, by a mechanical hang-up, or by the corkscrew set a compressed string takes. In workover depths differential sticking is rare; the grip is usually mechanical, which is why washover pipe and jars earn their day rates.
Does fishing always use the workover rig?
The rig runs the heavy fishing described here. Slickline and electric-line crews fish their own small tools inside tubing, and coiled tubing fishes in live wells. The trades overlap and the best call on a bad day is often a specialist fishing-tool hand with the rig doing the pulling.
The series, and where Vexon fits
Previous: remedial cementing and casing repair. Next, the bookends of a well's life: completions and plug & abandonment. The pillar guide is workover rig services. Vexon provides fishing and workover rig services to qualified operators: get in touch and ask for our qualification form.