Introduction: Extending Liner Lifespan
This chapter provides a guide to maintaining and repairing frac pad liners, including measures for preventing damage and common techniques for identifying and assessing liner problems.
Preventive Maintenance
Regular maintenance is the most important measure you can take to avoid costly repairs or regulatory issues and maximize the lifespan of your liner. Following best practices for housekeeping and fluid management, including regular inspections, reduces the risk of significant liner damage and keeps operations running smoothly.
Regular Inspections
Establish a routine inspection schedule to identify and address emerging issues before more significant problems appear. The frequency of inspections will depend on factors such as the liner material, site conditions, and operational intensity. However, regular visual inspections should be conducted in specific instances.
- Before each fracking operation, inspect the liner thoroughly to ensure it's in good condition and ready for use.
- Conduct periodic inspections during fracking operations to detect signs of wear, damage, or leaks.
- Inspect the liner after the completion of each fracking operation to identify and evaluate any damage or wear that may have occurred.
Good Housekeeping
Remember the old adage, an ounce of prevention is worth a pound of cure?
- Regularly remove debris, sharp objects, or tools that could puncture or damage the liner.
- Promptly clean up spills and leaks to prevent the fluids from remaining in contact with the liner for an extended period, which may degrade it.
- Store equipment and materials carefully to avoid placing excessive weight or stress on the liner. Equipment should never be dragged or dropped on the liner, which could cause abrasion, tears, or punctures.
Fluid Management
Careful fluid management is necessary to prevent liner degradation.
- Use liner materials compatible with the fracking fluids in use, and avoid making changes to the formulation that will put your liner material at risk. Consult the liner manufacturer's recommendations for information on chemical compatibility.
- Monitor and control the pH of fracking fluids to avoid extreme acidity or alkalinity, which may damage liner materials.
- When moving or transferring flowback and produced water, proceed carefully to avoid spills or leaks.
Assessing the Liner with Visual Inspections
Visual inspections are the foundation of preventive maintenance and damage assessment for frac pad liners. Thorough visual inspections performed on a scheduled basis help identify potential issues and provide an opportunity to rectify them.
What to Look For During Inspections
Signs of wear and tear
Check for abrasions, punctures, cracks, or other signs of damage to the liner material. Pay close attention to high-traffic areas, areas around equipment, and locations where the liner may be subject to stress or abrasion.
Seam integrity
Inspect all seams for any signs of separation, gaps, or leaks. Areas where seams intersect or change direction are generally more susceptible to stress and potential failure, so pay extra attention there.
Anchor trench condition
If the liner is anchored in a trench, make sure the liner is still securely anchored and there are no signs of erosion, settlement, or liner movement. Look for gaps or voids in the backfill material that could compromise the liner's anchoring.
If the liner has been secured with other methods, make sure those anchor points are secure, and there is no visible damage around the points of contact.
Penetration seals
Take advantage of planned downtime or when the tank is emptied for other reasons to inspect all penetrations (pipes, conduits, sumps, etc.) to ensure the seals are intact with no signs of leaks or damage. Look for cracks, gaps, or signs of deterioration in the sealing materials.
Drainage
Verify that the drainage system is functioning correctly and that water flows freely away from the frac pad to prevent ponding. Check for blockages or obstructions in the drainage system.
Overall liner condition
Observe the overall appearance of the liner, checking for indications of stress, deformation, or deterioration. Signs of deterioration include discoloration, staining, brittleness, or reduced flexibility. Changes in appearance, especially when they increase over time, warrant additional attention.
Sooner is Better: Identifying and Assessing Liner Damage
Despite preventive measures, frac pad liners can be damaged by heavy equipment traffic, accidental punctures, or prolonged chemical exposure. Early detection and assessment of liner damage so that timely repairs can be made is a cornerstone of good maintenance.
Leak Detection Methods
If visual inspection suggests a hidden leak or one that can't be pinpointed, there are several advanced leak detection methods that can help.
Vacuum Testing
This method applies a vacuum to the liner system and monitors for pressure changes. An increase in pressure signals air is entering the liner, indicating a leak. Trace the source of the pressure change to pinpoint the leak.
Air Pressure Testing
Similar to vacuum testing, the liner system is pressurized and monitored for pressure drops, which signal that air is escaping the liner. For a less technical method, a soapy water solution can be applied. If air bubbles appear, there are leaks.
Tracer Dye Testing
In the dye method, a brightly colored dye is introduced into the contained liquid and observed for movement where the fluid flows toward the leak. This method can be particularly helpful in locating leaks in complex liner systems or areas with difficult access.
Electrical Conductivity Testing
Conductivity testing is a more sophisticated detection method that requires specialized equipment. Liner materials generally act as electrical insulators, so when the leak breaches the liner, the current can readily escape through the breach. Testing equipment measures the liner's electrical current at several points, and changes in the readings signal damage or leaks. Conductivity can be more sensitive to small breaches than other testing techniques, especially in liners with inherently low conductivity.
Assessing the Damage
Once a leak or damage is identified, the extent and potential impact should be quickly assessed to determine the appropriate repair strategy.
Size and Location
Small punctures or tears in accessible areas are usually easy to repair. Conversely, large areas of damage or problems in an area dense with penetrations may require more complex repairs or liner replacement.
Cause of the Damage
If possible, isolate the cause of the damage to prevent the problem from recurring. For example, if damage is caused by heavy equipment traffic, an adjustment in operational procedures may solve the issue.
Establish Priorities
To help prioritize the repair, evaluate how quickly and to what extent the leak may affect the environment or lead to regulatory issues. This will also inform decisions on what additional containment measures should be taken.
