Oil, Gas, & Petrochemical

Ethane Pipeline 2 – Transient Analysis: Modeled a short 10″ Ethane pipeline in Pennsylvania to determine the effects of various valve closures.

Refinery Shutoff Valve Closure – Transient Analysis: Modeled several flow paths and pipelines at a refinery to determine safe closure time of a new shutoff valve at a storage tank. Analyzed various fluids (Heavy Virgin Naphtha, Debutanized Naphtha, Gasoline, etc.) over a wide range of temperatures. Determined proper valve size and type minimized the amount of time required for safe closure.

Ethane Pipeline 1 –Transient Analysis: Modeled an Ethane pipeline containing a series of valves over varying elevation. Determined maximum and minimum injection pressures for varying combinations of valve closures that ensured operation below MAOP and above vapor pressure. Included the theoretical effects of a pump trip without information about the specific pump curve.

Propane Pipeline 2 – Transient Analysis: Modeled a propane pipeline containing a series of valves over varying elevation. Determined maximum and minimum injection pressures for varying combinations of valve closures that ensured operation below MAOP (Maximum Allowable Operation Pressure) and above vapor pressure. Included the theoretical effects of a pump trip without information about the specific pump curve.

4″ Hydrocarbon Pipeline – Transient Analysis: Modeled a short 4″ hydrocarbon pipeline in Pennsylvania to determine the effects of various valve closures.

Propane Pipeline 1 – Transient Analysis: Modeled a propane pipeline containing a series of valves over varying elevation. Determined maximum and minimum injection pressures for varying combinations of valve closures that ensured operation below MAOP (Maximum Allowable Operation Pressure) and above vapor pressure.

Vacuum Gas Oil Pipeline – Transient Analysis: Modeled a vacuum gas oil pipeline that ran from tank to a loading dock. Determined surge behavior, recommended changes to normal startup, shutdown, and emergency operations to prevent excessive surge, and sized a surge relief valve.

Ship Loading Line – Transient Analysis: Modeled a ship loading line that delivered both heavy and light crude to tankers. Analyzed surge during emergency shutdowns and the closure of an emergency release coupling. Provided recommendation for changes operation to help alleviate excessive surge.

Diesel Rail Offloading – Transient Analysis: Constructed and analyzed a transient hydraulic model of a diesel rail offloading site. Evaluated emergency shutdown conditions and determined optimal valve closure timings. Alerted client to significant hydraulic issues and sized a bladder accumulator to prevent over-pressurization.

Fuel Oil Terminal to Refinery Pipeline Surge – Transient Analysis: Determined if pipeline pressure would exceed maximum allowable operating pressure during various valve closures at a refinery. Determined if existing surge protection was adequate.

C3 Pipeline Surge – Transient Analysis: Determined maximum and minimum pressures for a C3 pipeline during various emergency shutdown events. Analyzed various pipe sizes and pump configurations to determine if the maximum allowable pressure would be exceeded during an ESD event in the current configuration or future planned configurations.

NGL Pipeline – Transient Analysis: Performed a transient hydraulic analysis on a 14-mile-long NGL pipeline. Various valve closure rates and a loss of power scenario were analyzed. The pipeline model was calibrated to match steady flow conditions and resulted in a more reliable analysis.

Ethane Residue Blending Line – Transient and Pipe Stress Analysis: Investigated the root cause of a surge event that resulted in a broken u-bolt on an Ethane blending residue line. Performed a transient hydraulic analysis using AFT Impulse and a pipe stress analysis using CAESAR II. PMTG Provided recommendations to prevent excessive surge in the future, an analysis of the transient hydraulic forces that occurred during the surge event, and pipe support recommendation.

Fuel Oil Terminal Expansion– Transient Analysis: A fuel oil terminal in Texas underwent an expansion. PMTG was involved in sizing and establishing cracking pressures for various surge relief valves, assisting in locating surge relief valves effectively throughout the terminal, and determining automation logic for pump trips and valve closures. As part of the analysis, several different methods of surge mitigation were considered including alternative valve closure rates. This resulted in the elimination of several previously required sets of surge relief valves and a total savings of $1.25 million for the client.

Overfilling Diesel Tank – Transient Analysis: A 10 ft diameter diesel tank was evaluated in several different operating conditions to determine what vent line size, pipe and hose length, and flow rate would prevent overflow.

Gathering Line – Transient Analysis: Modeled a large crude oil gathering system including several injection points. The maximum and minimum mainline pressures resulting from several valve closures were determined.

Oil Pipeline Pump and Valve Sizing – Transient Analysis: Sized pumps and back pressure valves on a 75-mile pipeline. Determined valve closure timings during pump trip events to minimize the amount of system draining while preventing excessive surge pressures.

C2 Pipeline – Transient Analysis: Evaluated a liquid ethane pipeline that shares the same right of way with a previously defined model. Maximum and minimum flowrates were determined for steady operation and four surge scenarios were considered to prevent system overpressure and pressures dropping below the fluid flash point.

Mixed Hydrocarbon Pipeline – Transient Analysis: A previously developed hydraulic model was used to evaluate the potential that an ESD (Emergency Shut Down) valve closure would result in excessive surge pressure at the ESD inlet. To mitigate the surge pressure at the inlet of the ESD, Purple Mountain technology Group determined the maximum allowable shut off head at an upstream valve.

LPG Marine Export Terminal – Transient Analysis: Conducted a surge analysis on a liquefied petroleum gas marine export terminal used to pump liquid propane, butane, and gasoline (C5+) onto petroleum shipping vessels. Pre-existing models were used for the four different operational scenarios after being reviewed for completeness to ensure an appropriate level of detail is present for the surge analysis.

Oil Pipeline and Pumping Stations: Phase 2 – Steady State Analysis: Added 6 more flow scenarios to a previously complete steady-state analysis over a 75-mile section of an oil pipeline. These scenarios included testing a new control valve used to throttle the system to achieve an even lower minimum flowrate that previously possible.

Hydrocarbon Pipeline – Steady State Analysis: Developed a hydraulic model to evaluate system properties of a pipeline at various oil flow rates. The model started at a pumping station containing two pump banks and seven total pumps to allow for many different flow rate possibilities without prematurely wearing out equipment.

Petrochemical Cooling Tower System – Steady State Analysis: Developed and calibrated a hydraulic model of a Cooling Tower System. Seven total scenarios were tested including various pump layouts, piping restrictions, and cells in use.

Oil Pipeline and Pumping Stations: Phase 1 – Steady State Analysis: Developed a hydraulic model to evaluate 21 different scenarios for fluid flow in a pipeline with 3 different injection/booster stations. Scenarios ranged from 25,500 BPD to 100,000 BPD.

Natural Gas Liquids Processing Plant/Pipeline – Transient Surge Analysis: An independent transient surge analysis was required to evaluate the general valve behavior within a liquid ethane pipeline and connection to a metering station. This includes reviewing a surge event which caused overpressure in part of the system.

Natural Gas Liquids Processing Plant Expansion – Transient Analysis: Third phase of a natural gas liquids processing plant which expanded the previous model to include a second stabilizer and two new de-butanizers.

Mixed Hydrocarbon Pipeline Additions – Transient Analysis: Modified a transient model to reflect additions to the 70-mile hydrocarbon pipeline and conducted a transient hydraulic analysis to determine maximum and minimum pressures during surge events.

Onshore Terminal – Transient Analysis: Developed and calibrated a transient hydraulic model for an onshore terminal. Evaluated valve closure scenarios for various movements between inbound and outbound pipelines, tanks, and ship docks.

Mixed Hydrocarbon Pipeline – Transient Surge Analysis: Developed a transient hydraulic model of a 70-mile hydrocarbon pipeline and performed a transient surge analysis scenario where all valves in the pipeline closed over a 60 second period.