Introduction
Surge analysis is vital to ensuring safe and efficient fluid transport in polymer injection systems, particularly in Enhanced Oil Recovery (EOR) and chemical flooding operations. These systems are vulnerable to transient pressure spikes caused by pump trips, valve closures, or sudden flow changes, which can jeopardize pipeline integrity. A structured surge assessment helps prevent equipment failure, downtime, and non-compliance with operational standards.
Methodology
- Industry Standards: All surge studies were performed in compliance with ASME B31.3 for polymer service lines
- Transient Simulation Tools: Advanced tools like PIPENET Transient Module were employed to simulate pump startup, shutdown, and emergency valve actuation events.
- Pipeline Materials & Equipment: Analyses included GRE, HDPE, and carbon steel pipelines, alongside critical components such as chemical injection pumps, control valves, and remote-operated isolation valves.
- Mitigation Strategies: To control peak transient pressures, practical solutions such as optimized valve closure rates, pump trip coordination, and surge protection devices (e.g., surge vessels and air valves) were proposed.
- Vacuum Risk Evaluation: Pipelines were assessed for susceptibility to vacuum-induced damage or cavitation, ensuring structural stability under worst-case operating conditions.
Conclusion
Surge analysis in polymer injection systems plays a crucial role in protecting pipeline infrastructure and maintaining process reliability. By leveraging dynamic modeling and adhering to established industry codes, surge studies deliver cost-effective, safety-driven strategies that improve system resilience across upstream and midstream operations.
1. Surge Analysis for the Alkali Surfactant Polymer Service Pipelines of HAL Offshore
A surge analysis was conducted for a polymer injection pipeline system. The system involved the transportation of softened water and alkali surfactant polymer solutions across modular well pads. The objective was to assess pressure transients under critical scenarios like pump trips and emergency valve closures, ensuring the system’s compliance with safety standards and long-term integrity under dynamic loading.
Using the PIPENET Transient Module, several operating scenarios were simulated, including:
- Instantaneous pump trips
- Delayed valve closures
- Emergency shutdowns of booster and transfer pumps
- Flow stoppage in modular well pad transfer lines
Equipment and System Components Assessed
The pipeline system and simulation included the following components:
- Centrifugal Water Injection Pumps
- Remote Operated Shutoff Valves (XSVs)
- Flow Control Valves (FCVs and PRVs)
- Polymer Injection Units and Skids
- GRE and CS Pipelines, designed as per API 5L Gr. B and IS 1239 specifications
Mitigation strategies such as extending valve closure times (e.g., 20 to 280 seconds), coordinating pump shutdowns, and ensuring full vacuum resistance were evaluated to optimize surge behavior and reduce risk.
Results and Outcomes
- All observed surge and vacuum pressures remained within allowable design thresholds.
- Structural integrity was confirmed for both GRE and CS pipelines under dynamic load conditions.
- No additional surge protection equipment (such as accumulators or rupture discs) was required.
- Recommendations included operation-friendly mitigations that aligned with standard EOR processes.
The surge analysis validated the reliability and safety of the polymer injection pipeline system under a wide range of transient hydraulic events. By adhering to ASME B31.3 and B31.4, and applying precise transient modeling, the study ensured operational resilience, minimized downtime risks, and supported long-term infrastructure sustainability in EOR environments.