From the process control point of view, any reliable and online Oil-in-Water (OiW) measurement could provoke a brand new control paradigm for produced water treatment. However, the real-time OiW monitoring is still an open and ad-hoc situation in recent decades. The fundamental issue, ie, the OiW measurement is methodology dependent, leads to numerous challenges, such as (i) how to verify the reliability and accuracy of a specific methodology/instrument; (ii) how to handle and interpret the measured data in a most objective manner; and (iii) how to keep a cost-effective on-site calibration and maintenance under the harsh offshore conditions etc. The paper reports our latest achievements and observations in usage of fluorescence- and microscopybased OiW monitoring technologies for advanced Produced Water Treatment (PWT) control and evaluation, particularly by focusing on the de-oiling hydrocyclone installations.
To clean the produced water is always a challenging critical issue in the offshore oil & gas industry. By employing the plant-wide control technology, this paper discussed the opportunity to optimize the most popular hydrocyclone-based Produced Water Treatment (PWT) system. The optimizations of the efficiency control of the de-oiling hydrocyclone and the water level control of the upstream separator are discussed and formulated. Some of our latest research results on the analysis and control of slugging flows in production well-pipeline-riser systems are also presented. The ultimate objective of this research is to promote a technical breakthrough in the PWT control design, which can lead to the best environmental protection in the oil & gas production, without sacrificing the production capability and production costs.
Due to the harsh weather conditions, severe spatial limitations and extremely high safety requirements, the indoor climate control for offshore oil & gas production platforms is much more challenging than any on-shore situations. For instance, the indoor pressure of man-board quarters should be kept all the way above the ambient pressure according to safety regulations. Meanwhile, the indoor air needs to be regularly changed in order to guarantee the indoor air quality. Both requirements could be possibly achieved by automatically manipulating either the throttle valve located at the terminal of the inlet channel in the considered Heating Ventilation and Air-Condition (HVAC) system, or the pressurization system located inside the inlet channel, or both of them in a coordinated way. A Model-Predictive Control (MPC) solution to control the inlet throttle has been proposed in our previous work. This paper proposes a set of control solutions to regulate the variable speed pressurization fan system such that the energy efficiency of the considered HVAC system can be explicitly considered. A combined feed-forward with a PI-based feedback control solution, and an MPC solution are proposed based on derived simple system models. Some preliminary simulation results show that both control solutions can keep the indoor pressure and the air circulation in a very satisfactory and robust manner, even subject to the presence of severe disturbances.
In recent years the issue of sulfur emissions from maritime transport has seen newfound attention. This chapter presents an overview of the main issues of sulfur emissions and the legislative framework that seeks to reduce the sulfur footprint of the maritime sector. It also analyzes potential modal shifts toward less efficient land-based modes which may happen as a result of sulfur regulations and investigates the related potential economic damage to ship operators. To that effect, this chapter presents findings from a recently finished project at DTU and the developed methodological framework that can be used to estimate such modal shifts, as well as to measure the efficacy of policy and ship operators’ measures to reverse such shifts.