GPR Survey for Refinery and Petrochemical Plants

What does an SUE survey cover inside a refinery?

It sets out to detect and map each buried service in the excavation area, then grades every line by how certain its position is. Subsurface utility engineering starts with your records and surface clues such as valve chambers and marker posts. Locators and radar then fix lines in plan, and a trial hole exposes any critical line under a tie-in.

In a GPR pass, a transmitter in the cart radiates electromagnetic waves downward. A receiving antenna times the return signal from each buried object, so ground penetrating radar (GPR) works as a geophysical survey of the shallow subsurface. Higher frequencies give high resolution in the top metre, while lower ones reach deeper with less detail.

A plant commissioned in the 1980s may have seen five or six revamps, each leaving its own buried records. One plant-wide base map is more cost effective than a fresh spot check before every job.

What is buried under a typical refinery or petrochemical plant?

Several networks often share a tight band below a process block.

• Fire water ring main and hydrant spurs – large ductile iron or coated steel water pipes.
• Oily water sewer and storm drains – concrete or clay gravity lines that a locator cannot trace alone.
• Buried product and crude lines – coated and cathodically protected, running to tank farms.
• Power and instrument cables – in sand-filled trenches, duct banks or bare soil on older units.
• Earthing grids and anode beds – a conductor mesh that shows on radar as repeating reflections.
• Abandoned lines – left after revamps and often missing from current drawings.

A locator follows metal lines, while concrete, clay and plastic need radar or a sonde, so metallic and non-metallic objects get separate passes. Our underground pipeline detection at a glance page covers each material.

How do permits and hazardous zones shape the field day?

Inside the battery limit, the permit decides when we start, where we stand and which instruments we may switch on. Most Indian oil installations follow the Oil Industry Safety Directorate work permit standard, OISD-STD-105.

1. Area classification: battery-powered survey electronics are not intended for classified zones, so scanning there needs your safety team's permit and gas testing.
2. Induction: the crew completes induction, PPE checks and the day's permit, with fresh sign-off for each new permit area.
3. Records: your engineer marks known lines, CP test posts and rectifiers on site.
4. Locator sweep: direct connection or induction on metal lines, with cathodic protection current recorded since it skews readings.
5. Radar grid and marking: profiles cross the expected run of services, then each line is painted in an agreed colour and photographed.

Which quality level does each refinery job need?

Match the level to the cost of being wrong, and expose lines wherever digging nears live hydrocarbon or fire water.

Each level is delivered as a separate layer in the drawing; our page on CAD and GIS utility mapping shows how the layers are organised.

Does the ground at a coastal refinery behave differently?

Yes. Radar loses depth in wet, saline ground, so a coastal site needs more locator work and more trial holes than an inland one. On the Gulf of Kutch, Reliance's twin refineries at Jamnagar form the largest single-site refining complex in the world, and Nayara Energy's refinery stands nearby at Vadinar. Salt-laden soil there soaks up the pulse, so plastic and concrete lines get trial holes earlier.

Inland, Indian Oil's refineries at Panipat in Haryana and Mathura in Uttar Pradesh sit on alluvial soil, where radar reaches further. Panipat also has a large petrochemical complex beside the refinery, so the buried network crosses more than one plant boundary. Mezux Touch has scanned plant areas for refiners such as Indian Oil, Reliance and Nayara Energy on their own work orders. It also surveys for the EPC contractors working inside these refineries.

What do you receive after the survey?

A layered CAD drawing, line register and photos: underground utility mapping tied to your plant coordinates.

• DWG and PDF drawing showing each service by type, quality level and, where measured, depth.
• A line register stating how each service was detected and what doubt remains.
• Trial hole sheets for QL-A points, with photos and measured cover.
• Paint marks for the dig crew and a photo log; GIS layers on request.

For a quick check before one excavation, the pre-excavation scanning scope is lighter and faster than a full SUE survey.

What does a GPR survey for refinery work cost?

Radar scanning is priced per metre, and the written quote lists trial holes, extra permit days or night work separately.

• Standard GPR scan: ₹24 per metre.
• L-section scan (longitudinal profile with depth): ₹32 per metre.
• Minimum order: ₹50,000 in Delhi NCR and ₹1,00,000 elsewhere in India.
• Whole-order discounts: 25% above 100 km, 40% above 500 km and 50% above 1,000 km.

GST extra. Slab examples are worked through on the GPR survey price list. Permit waiting time drives refinery costs most, so state your working hours when you ask.

How long does a refinery survey take, and what do we need?

One excavation area takes one or two field days; a full process block or tank farm is staged, and permits shape the schedule more than area does.

Send a marked-up plot plan, the purpose (design, piling, tie-in or base map), the quality level for each zone and your induction rules. Use the form on this page or get a written quote by email.

Inside Delhi NCR, our crew scans the same day your permit is signed, or the working day after. Elsewhere in India, our colleague resident in that state is on site within a working day of the permit being signed. Any travel or mobilisation charge, where one applies, appears in the quote.

Frequently asked questions

Can GPR be used inside a hazardous area of a refinery?

Only under a permit from your safety team, with gas testing as directed. Otherwise we work from the nearest safe boundary.

How is SUE different from a simple GPR scan?

A GPR scan finds anomalies along its lines. SUE adds records, surface features, locator tracing and trial holes, then gives every line a quality level that tells designers how far to rely on it.

Do you dig the trial holes yourselves?

We supervise and log each trial hole. Your own contractor digs it under the plant permit, using hand tools or vacuum excavation beside live lines.

What safety points should we plan before the survey?

Permit timing, escort, area classification and the location of CP rectifiers. Our SUE survey safety refinery guide lists the checks in order.

Can you survey during a turnaround?

Yes. A turnaround is often the best window, because some lines are isolated. Book early, as shutdown crew days are planned weeks ahead.

Will the drawing match our plant coordinates?

Yes. Share two or three known plant grid points and we tie the survey to them, so the layers fit your existing plot plan.

Written by Saniya Parveen · Technically reviewed by Rahul Rai · Updated 8 November 2026