Pressure Pulse Inversion for Blockage and Deposition Analysis
Locate blockages, deposits and leaks in a pipeline or flowline from one closed-valve pressure trace. A non-intrusive pipeline inspection method that needs a valve, a pressure transducer and this tool — no pig, no shutdown, no excavation.
How pressure-pulse pipeline inspection works
A valve closes quickly and sends a pressure step along the line at the acoustic wave speed. Every change in cross-section — a wax or hydrate deposit, scale, a partial blockage, a leak, a change of wall thickness — reflects part of that step back to the transducer. The arrival time of each echo gives the distance to the feature (x = a·Δt/2), and its amplitude gives the severity: for a blockage the remaining flow area is A′/A = (1 − r)/(1 + r), while a leak produces a negative reflection whose size gives the leak flow.
The tool is a full method-of-characteristics water-hammer model with friction, variable-area reaches and orifice leaks. It simulates the test, inverts the reflections, and then shows three curves together: the measured data, the forward model for a uniform pipe, and the inverse model whose area-versus-distance profile reproduces the data.
What you get from a single hammer test
- Blockage or deposit position from the valve, with a 1σ uncertainty from wave-speed error, sample rate and closure time
- Remaining cross-sectional area and deposit extent
- Leak position and leak flow rate
- An echo table listing every reflector, including weak ones, so false alarms are visible rather than hidden
- A one-click sensitivity sweep across noise, sample rate and closure time with detection and false-alarm counts
- Rms misfit of the uniform-pipe forward model versus the recovered profile
Bring your own field data
Upload CSV or TXT transducer traces in metres or feet of head, Pa, kPa, bar or psi; the tool converts to head using the test-fluid density. Set the pipe length, diameter and wave speed and the inversion runs on your data. Validated against an independent transient solver (TSNet): a leak placed 300 m from the valve was reported at 307 ± 9 m.
When to use it
Screening of oil and gas flowlines and export pipelines for wax, hydrate, asphaltene and scale deposition; locating partial blockages before a pig run; leak location on water mains, district heating and process pipework; verifying cleaning-pig effectiveness. It is a single-line screening tool — the Method panel states the assumptions (constant wave speed, quasi-steady friction, no branches or column separation).
Frequently asked questions
Can a pressure test locate a wax or hydrate blockage in a flowline?
Yes. A partial blockage reflects part of a pressure pulse back to the transducer. The echo time gives the distance to the blockage and the reflection coefficient gives the remaining flow area, so a single valve-closure test can locate and size deposits without pigging or intervention.
How accurate is pressure-pulse leak location?
Position error scales with wave-speed uncertainty: a 3 % error in wave speed gives roughly 3 % in position. The tool propagates this together with sampling and closure-time effects and reports each position with its uncertainty. On an independent solver benchmark a leak at 300 m was located at 307 ± 9 m.
What equipment do I need for a water-hammer inspection test?
A valve that can be closed in a few tens of milliseconds, a fast pressure transducer near the valve sampling at 500 Hz or faster, and a known pipe length and wave speed. The tool shows how detection degrades with slower closure and lower sample rates.
Does this replace inline inspection (pigging)?
No. It is a non-intrusive screening method that tells you where to look and how severe a restriction is, so that pigging, cleaning or intervention can be targeted. Unpiggable lines and subsea flowlines are typical applications.
What data format can I upload?
CSV, TSV, TXT or DAT files with a time column and a pressure or head column, in m, ft, Pa, kPa, bar or psi.