Challenges with "Unpiggable" 3" to 24" Pipeline Inspections
Thursday, November 1, 2018

Challenges with "Unpiggable" 3" to 24" Pipeline Inspections

PICA has Solutions

In the past, certain pipelines were deemed “unpiggable” due to challenges that could not be overcome by technology available at the time. Much has improved since then, though obstacles are still encountered on a regular basis.

The three most important things we have learned over the years are:

1. Conducting research and thoroughly reviewing all available client records, is extremely important to avoiding challenges.

2. Planning and collaboration are imperative to a successful inspection.

3. Critical to have good communication and build a relationship with the client to understand all needs or challenges they may have.


Some of the challenges that PICA encounters when providing ILI services to clients are:

  • Demand on pipeline (short or no shutdown window)
  • Bends/topography (elevation changes, undocumented/wrongly documented bends/tees, multiple bends)
  • Bore restrictions in pipeline – can prevent full access of tool to pipeline
    • Construction features
    • Solids build-up, tuberculation
    • Undocumented changes in pipe diameter, unknown restrictions
    • No As-Built drawings available
  • High pressure environment (compressed air, water or other)
  • Toxic/environmentally hazardous product
  • Tool tracking
    • through wilderness – wildlife hazards (bears, insects), environmental hazards (cold, waterbodies, snow/landslides), lack of cell service
    • highway traffic
    • restricted access
  • Interference/noise
    • Electrical (railway tracks, powerlines buried or overhead)
    • Travel noise if much tuberculation.  Rough surface.
  • Tool access (Congested RoW/access locations – other infrastructure, machinery access)
  • Extreme weather (-40°C to 40°C+ from Alaska to Saudi Arabia; snow storms, etc.)
  • Other activities in area (vehicle or airplane traffic; near stadium during football season)
  • Tool damage caused by rough travel in pipeline (Abrasive pipeline interior, many bends can cause damage to tool parts)


The list of challenges to pipeline inspections can be long. PICA’s list of innovative solutions is equally long. PICA thrives on creating solutions for inspecting these “unpiggable” pipelines.

Most of the challenges identified above can be solved simply by performing detailed research and planning. Other challenges may need more elaborate solutions and have led PICA to improve tools, innovate new designs, and develop new procedures.

The tools PICA employs are designed specifically for challenging environments. They have been tried and tested in the field and improvements are continuously being made to them as we take on more difficult pipeline inspections.


Some of the solutions PICA has for these challenges include:

  • RFT tools can inspect pipelines without disrupting service by deploying in a free-swimming mode
  • Safety planning, management, hazard mitigation, training, experience
  • Tools are designed to be robust, and easy to repair on in the field
  • Designed to navigate tight/multiple bends
  • Custom built gauge tools to determine bore restrictions prior to RFT inspection
  • High resolution tools, in a range of sizes, provide options when dealing with bore restrictions
  • The HydraSnake, See Snake and Chimera lines of RFT tools are rated to withstand significant pipeline pressures
  • Tools regularly run with an IMU (Inertial Measurement Unit) to record pitch and yaw data, creating a map of pipeline for client
  • Often analysis reveals undocumented construction features that are then recorded for the client             
  • Odometer and circumferential clock position measurements record where construction features are, number of pipes, and of course any defect indication locations
  • Custom built AGM units to track our tools, planning and preparation for tracking (first aid kits, food, water, extra clothing, batteries, flashlights, flares, radio contact, bear spray, etc.)
  • Safety procedures and certifications when working with hazardous product; steps taken to capture/dispose of caustic/toxic/hazardous products to prevent environmental damage
  • Interference/noise sources fully investigated prior to inspection, and data quality control performed on-site
  • Experience working in congested areas (safety procedures, planning)
  • External inspection tools (Bracelet Probe can be used in areas an ILI tool has no access)
  • Can assist developing progressive pigging programs (PPP) for optimal cleaning of pipelines prior to RFT inspection

PICA is driven to find solutions for clients to get the information they need about the condition of their pipeline. After all, Good Decisions Start with Good Information.