Hiltek Resource Recoverywith BioActive Services

Wellbore BioChemistry Root cause 1 of 7

Paraffin in Oil Wells: Causes, Costs and the Remedy

Paraffin wax builds up in the tubing, on the sucker rods and in the flowlines as crude cools on its way to the surface. It drives hot-oil jobs, rod pulls and lost production in stripper, marginal and fracked wells.

What it is and what it costs

Wax that comes with the crude

Thick, honeycomb-like paraffin wax filling a section of production tubingBlockage
From the oil
What it is
Long-chain hydrocarbons, C18 and heavier, dissolved in the crude.
What causes it
On the way up, the oil cools below its wax appearance temperature and loses the light ends and gas that keep wax dissolved, so wax crystallizes on the rods, tubing and flowlines.
Lifting costs: the usual fixes and why they repeat
Hot-oil jobs, solvent treatments and rod pulls, plus the power to lift heavier rods. They keep coming back because the oil keeps cooling and the long chains keep arriving. An Oil & Gas Journal survey found the best programs hot-oiling or hot-watering monthly on a fixed schedule, and others every 30 to 90 days.
Hidden cost
Part of the hot fluid goes into the formation, where melted wax can damage permeability, and wax pushed deeper can harden and stick the rods.
Profitability
Wax narrows the tubing until the rate falls, then hangs or parts the rods, and the well sells nothing until it is cleaned out or fished.
  • $546 per well a year for hot oiling alone, at 3 to 4 jobs a year, across 427 Texaco wells in West Texas (1988 dollars).
  • $47.6 billion a year: the expected worldwide cost of wax deposition, within a range of $14.7–330.6 billion.

What this does to a well’s life: Lifting Costs and Well Life

Sousa et al. (2022, 2023); Hicks, Oil & Gas Journal (1990).

Paraffin impact

Rod weight and flow: the cost of deferred maintenance

How much production does one hung well cost? What does it cost to fish a separated rod string? Half an inch of wax is enough to put both on the table.

Clean rod

0.00 in of wax

Added weight per 1,000 ft
0 lb
Tubing flow restriction
0%Full flow area open
Peak volumetric efficiency

Deferred maintenance

½ in of wax buildup

Added weight per 1,000 ft
~730 lb
Tubing flow restriction
73.1% lostOnly 26.9% of the flow area left open
High risk: hung rod and separation

Figures from the Hiltek and BioActive presentation. They match ½ inch of wax around a ¾-inch sucker rod inside 2⅜-inch tubing.

Stack of production tubing joints with their bores nearly closed by paraffin deposits
Paraffin buildup in the tubing. Wax narrows the bore of joint after joint, the restriction the rods and the oil have to work through.
Torn and twisted pipe and rod string pulled up at a wellhead after a fishing job
Catastrophic separation and intervention. A dropped, structurally compromised rod string pulled back to the surface after an expensive, multi-day fishing job.
The remedy

What ChainBreaker does about paraffin

BioActive microbes break long wax chains into shorter ones that stay liquid at lower temperatures, and the solvents they make keep the paraffin in solution, so it doesn’t fall out of the oil. Biosurfactants help detach the wax so it flows out with the oil.

It works between treatments, so the wax is handled as the oil arrives instead of after it builds up. On a 100-mile oil pipeline, continuous injection softened the paraffin, and cleaning pigs stopped getting stuck (pipeline case).

Hard, black deposits may be asphaltene, not wax, and need different handling: see how to tell them apart.

Start with a Production Pilot How ChainBreaker works

Sources for this section