A well-executed fishing operation follows a disciplined, step-by-step Oil & Gas Fishing operation procedure that maximizes success while minimizing risk. The Oil & Gas Fishing Market has codified best practices into industry-standard sequences, but each well presents unique challenges. For toolpushers, drilling engineers, and wellsite supervisors, a thorough understanding of each procedural phase—from initial assessment to final clean-out—is essential to avoid common mistakes and reduce non-productive time. This guide details a systematic fishing procedure, based on practices from major operators and service companies.
Phase 1: Detection and Assessment
The moment a string becomes stuck (cannot be moved up or down, or circulation lost), the fishing procedure begins. Immediate steps:
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Record all parameters: Depth, string weight, rotary torque, standpipe pressure, mud properties. Note any recent events (e.g., high torque, hole fill loss, tight spots).
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Attempt free the string: Apply limited overpull (20-50% of string weight) and torque (50% of running torque) with circulation. Do not exceed pipe yield strength. If no movement after 15 minutes, cease attempts (further pulling may wedge fish tighter).
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Determine stuck point using either:
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Stretch method (wireline): Run wireline to depth, pull up with measured overpull, measure stretch. Calculate stuck point depth (D = E x A x ΔL / F). Accurate to ±100 ft.
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Torque method: Rotate string at surface, measure torque at multiple depths; stuck point where torque-angle relationship changes. Less accurate but faster.
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Identify fish type and condition from drilling records: Is it drill pipe, collars, MWD tool, bit, or junk? What is its OD, ID, and material? Is it likely crushed, parted, or intact?
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Perform a “fish finder” run (impression block or caliper log) if the fish top is accessible. This confirms fish orientation (centralized or against wall) and top condition (clean, split, flared).
The Oil & Gas Fishing operation procedure emphasizes “measure twice, fish once.” Incomplete assessment is the leading cause of fishing failure.
Phase 2: Plan and Tool Selection
Based on assessment, the fishing supervisor selects primary and backup tools and writes a written procedure:
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Select catch method: Internal (spear) if fish ID is accessible and undamaged; external (overshot) if OD is good; tap (die collar) as last resort. For broken bit or junk, plan milling.
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Select jar type and placement: Hydraulic jar should be placed 30-100 ft above the catching tool. Spacing affects impact intensity. Deeper and stiffer strings require shorter spacing.
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Determine jarring parameters: Initial overpull (usually 50% of estimated jar trigger), maximum overpull (80% of string tensile yield), expected blow count.
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Select milling parameters (if needed): Mill type (flat bottom, tapered, pilot), recommended RPM and WOB, expected penetration rate.
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Plan debris management: Mud properties (viscosity, gel strength) to carry cuttings; plan for magnet or junk basket runs every 2-4 hours of milling.
The plan also includes contingency if the fish is not recovered after 2-3 days: options include sidetracking, plugging back, or abandonment. The Oil & Gas Fishing operation procedure should be reviewed with the entire rig crew in a safety meeting.
Phase 3: Rig Up and Tool Assembly
Proper assembly prevents tool failure at depth:
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Inspect each tool as it comes out of its box. Check for damage to threads, grapple teeth, and seal surfaces. Document serial numbers.
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Lubricate all connections with API modified thread compound (50% zinc). Do not use standard pipe dope.
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Torque connections to manufacturer specifications (record torque values). Overtorquing can split boxes; undertorquing leads to back-off.
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Function test jars on surface by pulling with a crane or test stand. Verify trigger values (e.g., 50,000 lbs triggers jar).
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Assemble string from bottom up: fish catch tool → jars → accelerator (optional) → drill pipe. Mark each tool’s position with paint.
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Perform a “drift run” (run a gauge ring down the string) to ensure no obstructions.
All joints should be tagged with a unique number and depth in the tally book.
Phase 4: Run in Hole and Engage Fish
Lower the fishing string carefully:
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Fill string every 10-15 stands to avoid collapse from external pressure.
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Monitor weight and torque continuously. Any unexpected increase indicates debris or ledges.
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Approach fish top slowly (5-10 ft/min). When tag is felt (weight drops by 2,000-5,000 lbs), stop.
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Engage the fish:
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For overshot: Lower slowly until the fish enters the bowl; set down weight (10,000-30,000 lbs) to expand grapple; rotate 1/4-1/2 turn right to set; test pull (10,000 lbs over engaged weight) to confirm grip.
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For spear: Similar but set down weight to expand grapple outward.
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For die collar: Rotate 5-10 turns while lowering slowly to cut threads.
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Verify engagement by picking up weight: a good grip shows no movement at initial pull. If no grip, reset and re-engage.
The Oil & Gas Fishing operation procedure warns against high rotation or jarring before confirming good engagement—this can damage the fish top, making subsequent attempts harder.
Phase 5: Jarring or Milling
With fish engaged, attempt to free and pull:
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Jarring:
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Start with low overpull (e.g., 20,000 lbs above trigger). Pull up; jar fires. Wait 30 seconds for jar to reset.
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Increase overpull in increments (10,000 lbs per 10 attempts) up to maximum safe.
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Monitor fish movement: if it moves up 1-2 ft per blow, continue. If no movement after 50-100 blows, consider switching to down-jarring (if fish is stuck in a keyseat).
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If fish moves but then stops, the wellbore may be bridged. Pump sweeps (high-viscosity mud) to clear.
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Milling (if jarring fails or fish is junk):
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Drop or pump a mill to fish top. Start rotation (50-60 RPM), slowly lower until mill contacts fish.
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Apply weight (5,000-15,000 lbs) and increase RPM to 80-120. Maintain steady torque.
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Monitor returns for metal cuttings; adjust parameters to avoid balling (torque spikes).
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Pump sweeps every hour to clean hole. Run magnet every 2-3 mills to retrieve cuttings.
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Mill until fish is reduced to small pieces or a new fish top is exposed.
Throughout both operations, maintain circulation to cool tools and carry debris. Do not rotate or jar without circulation—tools may overheat and fail.
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Phase 6: Recovery and Clean-Out
Once the fish is dislodged or milled:
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Pull string out of hole slowly (maximum 10 ft/min) to avoid swabbing and losing the fish. Check weight and torque for drag.
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Lay down fish on catwalk and inspect. Document cause of sticking (e.g., keyseat, differentially stuck, bridge).
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Run clean-out assembly (magnet + junk basket + stabilizer) to bottom to retrieve any remaining debris.
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Record final depth and confirm no fish in hole by drifting (run a gauge ring to bottom).
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Prepare final report: including fish recovery time, tools used, jarring counts, milling parameters, and recommendations to prevent recurrence.
The Oil & Gas Fishing operation procedure concludes with a post-job review involving the drilling team and service provider. Key lessons are incorporated into future well plans.
Common Mistakes to Avoid
Even experienced crews make errors:
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Insufficient assessment leading to wrong tool selection (e.g., using overshot when fish OD is damaged).
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Jarring too hard too quickly causing the fish to part, leaving a new fish.
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Using old or untested jars that fail to fire at required tension.
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Not pumping enough sweeps during milling, allowing cuttings to settle and stick the string.
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Pulling too fast after recovery, swabbing the fish out of the overshot.
Following a rigorous, step-by-step oil & gas fishing operation procedure—from assessment through clean-out—is the most effective way to turn a costly stuck pipe event into a routine intervention. When in doubt, slow down, reassess, and consult the fishing supervisor. In fishing, patience is the most valuable tool.Gain valuable insights through comprehensive industry analysis:
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