Flowsol: Restoring Stable Flow in Deposition-Prone Gathering Systems

At a glance

A midstream oil gathering system feeding a refinery faced wax–asphaltene deposits from variable crudes and intermittent flow. After implementing Guardian’s Flowsol-based flow assurance program, pigging intervals were extended, flow disruptions avoided, and pig-trap waste reduced by 70% in the first six months.

Key metrics

PIGGING FREQUENCY REDUCED

FLOW STABILITY RESTORED

PIGGING WASTE DISPOSAL REDUCED 70%

How wax and asphaltene deposits shorten pigging intervals

Crude gathering lines carry oil from many sources at changing rates. When crude chemistry varies, flow starts and stops, and temperatures swing, wax and asphaltene can drop out and stick to the pipe wall. Deposits narrow the line, raise pressure, and force more frequent pigging.

Each pigging run takes time and produces solids that have to be collected and sent for disposal. As deposits build faster, the pigging window gets tighter, and the risk of a blockage goes up.

This refinery-fed gathering system ran 4 to 8 inch lines, including sections of poly pipe that are harder to treat. The operator needed longer pigging intervals without flow disruption, and less solid waste to dispose of.

Challenges

A refinery-fed crude oil gathering system experienced accelerated wax–asphaltene deposition driven by variable crudes, fluctuating flow rates, start-stop conditions, and temperature swings across 4–8 inch lines and sections of harder-to-treat poly pipe.

As deposits built, pigging windows tightened. The operation needed longer pigging intervals without flow disruption or blockages, while reducing the amount of recovered solids sent for costly disposal.

Solutions

The operator partnered with Guardian to characterize deposit samples and confirm wax–asphaltene composition through lab evaluation. With that input, a program was developed to disperse existing deposits and limit further agglomeration using Flowsol as the primary solvent/dispersant. Placement and dosage were set to match variable flow rates and mixed pipe materials.

Results

Pigging intervals extended under variable flow: Pigging frequency reduced while maintaining stable operation.

Waste disposal reduced in the first six months: Recovered pig-trap solids sent for disposal dropped 70% over the first six months of Flowsol treatment.

Operating approach standardized across assets: After stabilization, the program was adopted across 12 similar gathering systems.

Data

This data summarizes the system context and the first six months of operational outcomes following program implementation. It reflects variable-rate gathering service feeding a refinery, mixed pipe materials, and deposit behavior observed during pigging, with disposal reduction used as a practical indicator of improved solids handling and control.

Frequently asked questions

What was causing the deposits?

Lab evaluation of deposit samples confirmed a wax and asphaltene mix. Variable crudes, changing flow rates, start-stop operation and temperature swings were speeding up deposition.

How did Flowsol help?

Flowsol was used as the primary solvent and dispersant to break up existing deposits and limit new buildup. Placement and dose were set to match variable flow and mixed pipe materials.

How much did pig-trap waste drop?

Recovered solids sent for disposal dropped 70% over the first six months of treatment.

Was the program used anywhere else?

Yes. After the system stabilized, the same program was adopted across 12 similar gathering systems.