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Oil & Gas

A retired crude unit taken from final shutdown to regulator-cleared land inside a live refinery boundary.

Client
National Refining Company
Location
Gujarat, India
Duration
14 months
Material handled
9,100 t
Project summary

Turnkey decommissioning of a retired crude distillation unit including de-inventory, chemical cleaning, gas-freeing, column and vessel removal, pipe rack demolition, foundation removal and contaminated ground remediation — executed entirely within an operating refinery.

Scope of works

  • De-inventory, draining and chemical cleaning
  • Nitrogen purging and gas-freeing certification
  • Atmospheric column removal (48 m, 210 t)
  • Exchanger, drum and pump removal
  • Three-tier pipe rack demolition
  • Contaminated soil remediation and validation
The challenge

The unit was surrounded on three sides by operating process areas. Hot work was severely restricted and every permit had to clear the refinery's own authorisation chain, which limited daily work-front throughput regardless of manpower available.

The main atmospheric column had to be removed intact for structural reasons but there was no crane standing position within radius that did not sit over live buried services.

Historic spillage in the pump bay had produced hydrocarbon contamination to an unknown depth, discovered during the initial ground investigation rather than declared in the tender information.

Our approach

We built the programme around permit throughput rather than manpower, opening multiple parallel work fronts so crews were never idle waiting on authorisation. Cold cutting was adopted as the default method, reducing hot-work permit dependency by a large margin.

For the column, we designed a load-spreading crane platform that bridged the buried services corridor, verified by calculation against the recorded service depths and confirmed by trial pit. The 210 t column came out intact in a single engineered critical lift.

The contamination was delineated by a targeted investigation grid, and remediation criteria were agreed with the client and the state pollution control board before excavation. 2,300 m³ of impacted soil was removed and treated, with independent clearance sampling validating the result.

The full evidence pack — isolation certificates, gas-free certificates, lift plans, waste manifests, remediation validation and final survey — was compiled continuously and submitted as a single indexed dossier at completion.

Outcome

9,100 t

Material recovered

2,300 m³

Soil remediated

~70%

Hot work permits avoided

Granted first submission

Site clearance

Zero

Recordable incidents

Plant deployed

Equipment mobilised against the engineered method for this programme. Where the correct machine was not in our own fleet, it was brought in rather than substituted.

  • 500 t crawler crane
  • Cold cutting and diamond wire systems
  • Vacuum tankers and cleaning units
  • Long-reach excavators
  • Mobile gas detection and monitoring
Site record

Crude Distillation Unit Decommissioning — site record 1
Crude Distillation Unit Decommissioning — site record 2
Crude Distillation Unit Decommissioning — site record 3
Crude Distillation Unit Decommissioning — site record 4
Crude Distillation Unit Decommissioning — site record 5
Crude Distillation Unit Decommissioning — site record 6
Similar scope?

If this looks like your asset, we should talk.

Send us the structure, the environment around it and the date you need it gone. We will come back with a method.