Howard Duhon, P.E.
Topsides Operations Senior Advisor
38 years of work experience. First 15 years in Petrochemical Industry in process and project design roles. Last 23 years in Oil and Gas consulting roles. Last 12 years in Systems Engineering. Currently partially retired focusing on mentoring and HAZOPs. When I am not working or teaching I like to go fishing, play golf and tinker with my old 1946 Chevy truck.
Areas of Expertise:
Topsides process design, process simulation, dynamic modeling.
Process control, controller tuning
Operating procedures, commissioning procedures, initial startup procedures, operator training.
HAZOPs and SIL Assessment (process targeting) via novel techniques.
Axial mixing (longitudinal mixing) in the displacement of pipelines or umbilical tubes.
Application of decision theory to engineering decision making. Knowledge of relevant social science fields including psychology, sociology, cognitive science, sensemaking, action science, naturalistic decision making, and Bayesian reasoning.
Application of mathematical decision methods to engineering decision making including optimization techniques (Linear Programming, Monte Carlo simulation, decision trees, probability, statistics, data reconciliation).
Organizational learning, lessons-learned studies.
International leadership roles in Society of Petroleum Engineers.
Education:
Howard earned a Bachelor of Science, Chemical Engineering from the University of Louisiana at Lafayette.
We have many options for conducting root cause analyses (RCA) including TapRooT™ and CAST/STPA. The method described here is the method developed by GATE to simplify the analysis while maintaining adequate rigor.
The GATE approach to risk ranking makes risk assessment easier, more accurate and more repeatable by incorporating LOPA insights into the risk matrix approach.
HAZOP is the most commonly applied process hazard analysis (PHA) methodology in the processing industries. It is also the most flawed!
In Part 1 of this GATEKEEPER series on complexity, we identified 8 key sources of project and project team complexity. In Part 2, we discuss what can be done about them.
A project consists of two interacting networks; one CPS (the kit) and one CAS (the human organization). We should expect some surprises (emergence) from the interaction of these two complex systems.
This GATEKEEPER discusses an effective subsea tree PWV (USV) leak test method. The test can be done quickly – entire test time is about 15 minutes, including the 5 minute monitoring time.
A HAZOP is a team-based process hazard analysis (PHA) method. Its purpose is to identify hazards and operability issues in a process design.
LOPA provides a consistent basis for judging whether there are sufficient independent protection layers against hazardous events to achieve the risk reduction required to achieve such an explicit target.
This is part two of the GATEKEEPER series on control systems tuning. To effectively tune a control loop, there needs to be an understanding about the dynamics of the system.
This series of GATEKEEPERS will provide methods for using readily available process design data for determining effective tuning parameters before startup.
Proper sizing of the flowlines and risers coupled with optimal choking and gas-lift will greatly reduce the risk of slugging and help in efficient management of slugs throughout the life of the field.
Studies suggest that humans conducting simple, mundane tasks make an error roughly 1% of the time. Error rates for complex tasks are much higher. Some procedures are more error-prone than others. It is incumbent upon us to write procedures that are not only accurate, but that are likely to be implemented without error.
It is frequently necessary to displace the contents of a pipeline or umbilical tube (fluid B) with another fluid (fluid A). If we don’t use a pig to separate the liquids, there will be mixing at the interface (axial mixing). The mixing zone requires us to overflush the line to effectively remove fluid B from the line.
Asphaltenes are large, complex organic components present in the oil phase, along with resins, aromatic hydrocarbons, and alkanes (saturated hydrocarbons). Resins play an important role in stabilizing asphaltenes in crude oil. When the resins get destabilized, (under unfavorable pressure-temperature conditions) asphaltenes can agglomerate and deposit.
These work effectively on dispersed, O&G; however, these systems do not effectively remove water soluble organics (WSOs). Where WSOs exist in concentrations greater than 29 mg/l, conventional produced water treating systems cannot achieve GoM overboard discharge limits.
Methanol (MeOH) is widely used in multiple applications in the offshore oil and gas industry.
In subsea oil production systems, hydrate mitigation methods during steady state operation are almost always based around heat conservation.
Iron solid formation in the MEG regeneration system has been a recurring issue in wet gas pipeline systems.
In this 2-part GATEKEEPER series, we will discuss how centrifugal pumps work and what information is needed to determine the pump needed for a particular application.
In part 2, horsepower, efficiency and NPSH will be discussed which will lead to a final centrifugal pump selection.
Chokes and control valves are often oversized even for normal operation, and are sometimes far too large to provide adequate control of low flow rates at initial startup.
The Initial Startup is the moment of truth where everything from subsurface to topsides becomes a single entity and has to work together. Design disconnects will become apparent.
Chemical injection systems are difficult to size because of uncertainties including flowrate, chemicals used and their treatment rate. If conservative estimates are used for all parameters, the injection system may be oversized, at least for some wells.
