The Dry Gas Seal system is a critical protection system for centrifugal compressors. Its main function is to prevent process gas leakage from the compressor casing while minimizing emissions and avoiding liquid or solid contamination of the seal faces. For reinjection service, where gas pressure is high and gas composition may include hydrocarbons, CO₂, H₂S, water, or heavy components, proper seal gas conditioning is essential to maintain seal integrity and compressor availability. PE&T team evaluated existing seal gas supply arrangements and identified a cleaner and more reliable gas source to improve seal gas quality and reduce the risk of dry gas seal contamination and failure. The new conditioning unit was designed to provide a continuous supply of clean, dry, and stable seal gas under all operating scenarios. The design incorporated multiple stages of gas treatment and conditioning, including high-efficiency particulate and coalescing filtration, gas heating facilities, pressure control systems, and liquid knockout equipment. These features were integrated to ensure effective removal of liquids, aerosols, and solid contaminants while maintaining the required pressure and temperature margins across the dry gas seals.

Special consideration was given to start-up, shutdown, transient, and normal operating conditions to prevent liquid carryover, condensation, hydrate formation, and reverse process gas migration into the seal cavity.

A multiphase pump is used to reduce well backpressure and boost the pressure of the wellstream to plant conditions, thereby sustaining or increasing production from wells with declining reservoir pressure. The design considered the full operating envelope, including variations in gas volume fraction, liquid rates, fluid properties, pressure decline profiles, start-up and shutdown conditions, slugging behavior, and future field development scenarios. Hydraulic analyses were performed to evaluate system performance under both current and forecasted reservoir conditions.

The system was designed with proper process control and safeguarding features, including suction and discharge pressure protection, high temperature protection, minimum flow or recycle philosophy, emergency shutdown logic, isolation valves, non-return valves, pressure relief provisions, and suitable instrumentation for monitoring pump performance and operating limits with OEM.

Special attention was given to transient and abnormal conditions such as blocked discharge, low suction pressure, high gas volume fraction, slug flow, pump trip, downstream restriction, and start-up with unstable multiphase flow. The safeguarding philosophy was developed to protect the pump, piping, and downstream facilities while ensuring safe and reliable operation.

PE&T team led Pressure Safety Valve (PSV) adequacy assessments across the plant to verify the capability of the existing pressure relief system to safely handle both current operating conditions and planned production increases. The study evaluated a wide range of credible overpressure scenarios, including blocked outlet, control valve failure, thermal expansion, utility failure, exchanger tube rupture, fire exposure, and equipment-specific process upsets in accordance with applicable industry standards i.e API 520/521 and specific company requirements.

The relief load calculations were performed to determine required relieving rates, accumulation limits, backpressure effects, and flare system impacts for existing and future operating cases. The assessment considered the effect of increasing production rates on equipment pressure build up, relief loads, inlet piping, discharge network hydraulics, and flare system capacity to ensure that the pressure protection philosophy remained effective.

The study identified potential limitations within the existing relief system and evaluated mitigation options, including PSV resizing, additional relief devices, operating limit adjustments, and facility modifications based on the dynamic simulation outcomes.

PE&T team helped to develop integrated facility concepts that address the challenges associated with handling hydrocarbons containing high concentrations of H₂S, CO₂, water, and other contaminants while maximizing the utilization of existing infrastructure.

The concept development included establishment of the overall process scheme, assessment of processing capacities, identification of key equipment and facility requirements, and evaluation of different design options to optimize plant performance and project economics. Critical aspects such as gas sweetening, dehydration, sour gas reinjection, flare systems, utility requirements, and integration with existing facilities to ensure a robust and operable design.

Debottlenecking of plant facilities and increases in feed rates can introduce new constraints in key process equipment such as distillation and absorption columns. In one of P&T’s client facilities, the crude stabilizer and amine (AGRU) absorber columns experienced severe flooding, resulting in trip of flash gas compressors and upsets in downstream gas processing trains due to liquid carryover.

P&T carried out a detailed evaluation of column performance under varying operating conditions, supported by rigorous hydraulic simulation studies. The results of these assessments formed the basis for targeted gamma scanning, which confirmed the predicted flooding behavior.

Following validation, P&T engaged with column internals vendors to develop and implement upgraded tray designs. The modified columns are now operating with stable hydraulics, improved safety margins, and enhanced reliability under higher throughput conditions.

If you would like to evaluate feed capacity limitations or hydraulic performance issues in your process equipment, contact P&T at info@peng-tech.com.

The oil treatment facility was facing challenges with water and dissolved salts carried over to the Crude Stabilization Column. Entrained/dissolved water (together with dissolved salts) carried in with crude oil was arriving at the distillation column feed and condensed in the overhead reflux system forming a highly acidic aqueous phase that led to severe corrosion in the overhead circuit.

The original facility design expected a relatively dry distillation column overhead system and did not account for water carryover during dynamic operating conditions.

As a brownfield modification, PE&T developed a solution comprising overhead wash water, pH neutralizer, and corrosion inhibitor injection systems to mitigate acidic environment and reduce corrosion rates in the distillation column overhead condensing system.

If you are experiencing similar acidic corrosion mechanism in column overhead reflux system and looking for mitigation solution, contact PE&T at info@peng-tech.com.