Slugging occurs when irregular surges of gas and liquid flow through pipelines, often due to variations in pressure, flow rates, or system design, causing instability in downstream processes. Intensive slugging in oil and gas production systems such as separators poses critical operational risks, including: • Gas flaring, • Oil dripping events, • Costly production stops, and • Equipment damage requiring extensive repairs. Our client, a major oil and gas operator, required a sophisticated solution to evaluate the severity of slugging as it enters a separator. The model has to handle varying levels of system knowledge, integrate seamlessly with existing operations and work in both real-time scenarios and for evaluation of large-scale simulation results of future operarions.
Approach
We developed a flexible, multi-level framework of Slugging Severity Indicators, tailored to the client’s system and data availability. The solution delivered insights at varying levels of granularity, based on the level of system instrumentation and available data:
General Indicator (Minimal System Knowledge)
- Description: Spectral analysis of pressure and temperature variations (common measures at various points in the system)
- Application: Provides quick assessments with minimal system-specific input, enabling scalable deployment across diverse applications.
Intermediate Indicator (Flow Rate Knowledge)
- Description: Uses flow rates, derived from multiphase flow meters or transient flow simulations, to calculate surge volumes of slugs entering the separator.
- Application: ONers a more detailed evaluation, ideal for systems equipped with flow measurement tools or modeled data.
System specific Indicator (Digital Twin)
- Description: Incorporates a digital twin of the aNected components (separator and drainage control system), simulating real-world operations to predict slugging behavior.
- Application: Provides the most detailed analysis, supporting precise optimization of, e.g., separator performance.
The framework is designed to be modular, allowing the client to adopt the level of analysis most suitable for their operational context and scale up as needed.
Impact
Once fully implemented, the Slugging Severity Indicators enable significant operational benefits, including:
- Improved Monitoring: Real-time evaluations allow for a proactive responses to slugging events, reducing the risk of unplanned production stops.
- Enhanced Reliability: Optimized separator and drainage system performance increase overall system reliability.
- Cost and Environmental Savings: Fewer flaring and oil dripping incidents minimize both operational costs and environmental impact.
- Future-Proofing: Improved evaluation of scenario modeling using commercial multiphase flow simulators to plan for future operations and mitigate potential risks.