6-inch Re-assessment

Integrity expertise and field supervision provide midstream company with successful onshore pipeline re-assessment status.

Location: Louisiana


Nominal Size: 6-inch
OD: 6.625
WT: 0.188
MAOP: 1,715 psig
Pipeline Length: 25.5 miles


A midstream company operating a high pressure gas pipeline required assessment services in order to maintain regulatory compliance. The said pipeline asset was considered unpiggable for ILI technology. In order to comply with regulatory guidelines for an MAOP verification, the company demanded a hydrostatic pressure test assessment.

Scope of Work

The said re-assessment resulted in multiple pipeline integrity needs: internal pipeline cleaning, pipeline flooding, an 8-hour approved hydrostatic pressure test, pipeline de-watering and internal drying for product preparation.

Upon extensive site audits and risk assessments the final SOW divided the 26-mile segment into (2) two flooding segments. This divided contingency provided safeguard for several identified risks:

  • Protection against a compressed schedule due to water access supply.

  • Enabled opposing segment transition and minimal time loss in the case of necessary repairs.

Plan of Execution

1. Project Pre-planning

  • Pipeline site survey

  • Identify possible constraints/unknowns

  • Write technical procedure

  • SOW approval

2. Nitrogen Purging:

  • Assistance with nitrogen purging to maintain a pressure rating on the pipeline system while the operator conducted hot work tasks on the said asset.

3.Pipeline Flooding:

  • Utilization of a local water distribution source.

4. Hydrostatic Pressure Test:

  • 4-hour pressure stabilization period

  • 8-hour approved test of 2,200 psig

  • PE certified

5. Pipeline Dewatering:

  • Relinquish used test medium into natural surrounding

  • Test medium discharge satisfied state environmental regulations

  • Mechanical pigging systems

6. Pipeline Air Drying:

  • Achieved Dew Point of -40°F

  • Foam Swab Pigs

  • Urethane Coated Abrasive Pigs

Technical Achievements

  • Successfully executed Management of Change (MOC) orders to accommodate clean pipe specifications.

  • Executed 24-Hour SIMOPS schedule to complete SOW for a moving finish date.

  • Successfully executed hydrostatic pressure tests and certified by a Professional Engineer.

  • Jobs completed with zero incidents and no environmental impact.