Research and Practice of Neural Network PID Process Control Algorithm Based on Offshore Oil and Gas Platform

Epibenthic assemblages on vertical artificial substrates: recruitment and succession patterns in offshore Qatari waters

Offshore oil and platforms are found on continental shelves throughout the world’s oceans. Over the course of their decades-long life-spans, these platforms become ecologically important artificial reefs, supporting a variety of marine life. When offshore platforms are no longer active they are decommissioned, which usually requires the removal of the entire platform from the marine environment, destroying the artificial reef that has been created and potentially resulting in the loss of important ecosystem services. While some countries allow for these platforms to be converted into artificial reefs under Rigs-to-Reefs programs, they face significant resistance from various stakeholders. The presence of offshore platforms and the associated marine life alters the ecosystem from that which existed prior to the installation of the platform, and there may be factors which make restoration of the ecosystem unfeasible or even detrimental to the environment. In these cases, a novel ecosystem has emerged with potentially significant ecological value. In restoration ecology, ecosystems altered in this way can be classified and managed using the novel ecosystems concept, which recognises the value of the new ecosystem functions and services and allows for the ecosystem to be managed in its novel state, instead of being restored. Offshore platforms can be assessed under the novel ecosystems concept using existing decommissioning decision analysis models as a base. With thousands of platforms to be decommissioned around the world in coming decades, the novel ecosystems concept provides a mechanism for recognising the ecological role played by offshore platforms.

Wet flue gas desulfurization system is a desulfurization process which reduces flue gas SO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> content by acid-base reaction and PH value is the main control parameter. Since the system possesses time-varying, large inertia and nonlinear characteristics, the traditional PID algorithm is difficult to obtain satisfactory results in condition that a high demand of steady-state performance and control accuracy. So this paper proposed the method of RBF neural network online tuning PID control. The PID control is simple and easy to be used. The RBF network can tune PID parameters in real time based on the change of object parameters. The method combines both methods. The simulation results show that RBF neural network PID controller is better than the traditional PID controller, in the control effect of the system. It has a small amount of overshoot, short adjusting time and strong robustness, etc.

Offshore oil and gas platforms are a notable source of methane (CH4) in the marine environment, yet there remains a lack of comprehensive understanding regarding their impact along the coastal areas of China. Besides, relevant emissions are generally derived from systematic inventory and rarely quantified by top-down methods. To this end, a ship-based measurement of CH4 emissions from three offshore oil and gas platforms with different oil and gas production levels was conducted over the Liaodong Bay of China in August 2023. The results demonstrated that there were differences in CH4 background concentrations around the three platforms (2291 ± 15 ppb, 2468 ± 32 ppb and 2100 ± 12 ppb). At moderate wind speeds, CH4 levels showed a gradual increase as the ship approached the target upwind, with peak concentrations typically observed within a range of 2-3 km from the platform. Along with meteorological data and the Gaussian plume model, CH4 emission rates were determined corresponding to the average values of 229 ± 48 kg h-1, 59 ± 16 kg h-1 and 13 ± 8 kg h-1 for the three platforms. By analyzing the concurrent changes in carbon dioxide concentration, it was hypothesized that gas flaring was the primary source of CH4 emissions from one of the platforms. Additionally, when considering the revised emission factors for the oil and gas industry from the IPCC and combining them with the production data from the three platforms, the results clearly demonstrated a substantial contrast between top-down emissions and inventory emissions. Diverse platforms and continuous monitoring are necessary to validate the aforementioned perspective and ultimately enhance the precision of CH4 emission data provided to regulators and the general public.

In Malaysia, numerous offshore oil and gas platforms are approaching the end of their operational lifespans and will soon be scheduled for decommissioning. Traditional decommissioning typically involves the complete removal of the platform from the seabed, consequently resulting in the destruction of the established marine life communities present on the structure. A Rigs-to-Reefs strategy provides an alternative to the complete removal of obsolete, non-productive offshore oil and gas platforms, by converting the platform into a permanent artificial reef by utilizing one of the following three methods: partial removal or topple-in-place (in-situ), or tow and place (ex-situ). In-situ reefing provides a means of conserving the marine communities found on the platform by decommissioning the platform jacket in place as an artificial reef. However, not all platforms are good candidates for a Rigs-to-Reef conversion. Thus, pre-decommissioning biological assessments should be undertaken to determine the most appropriate decommissioning strategy on a case-by-case basis. In this study, a biological assessment was developed to catalog the marine life assemblages present on two offshore oil and gas platforms in Malaysia using remotely operated vehicles. Given the limited amount of biological data available on the marine ecosystems found on Malaysia’s platforms, this data may be useful for minimizing adverse impacts of platform removal, while enhancing benefits to the marine environment.

Offshore Oil and Gas platforms mostly utilize gas or diesel generators to produce reliable energy. As a step towards low carbon economy, Offshore Wind Energy is studied to reduce dependency on this fired turbomachinery. Since Malaysian Offshore Oil and Gas platforms are mostly situated in water depths deeper than 50 m, floating offshore wind turbine is considered. Floating offshore wind technology has roots on well-known platform designs from the Oil and Gas industry. However, specific solutions adaptations are required since floating platforms are expensive whilst floating offshore wind solution is cost driven. Furthermore, there is a need for high dynamic stability. Therefore, the fully coupled analysis (aero-hydro-servo-elastic simulations) will be briefly presented. This study will focus on GICON’s tension leg platform and ELEON’s single-sided supported direct drive wind turbine. The concept of hybrid microgrid is introduced as part of the bigger picture of energy transition towards low carbon technologies.

Black‐legged kittiwake (Rissa tridactyla) populations are in decline globally, including in Britain and Ireland, which support internationally important numbers. Although kittiwakes typically nest on coastal cliffs, they are known to colonise anthropogenic structures, including offshore oil and gas platforms. Lack of monitoring of offshore platform colonies represents a potentially important gap in our understanding of kittiwake population size and dynamics. The presence of nesting kittiwakes on oil and gas platforms presents a practical challenge for operators in relation to decommissioning and re‐purposing works. We use preliminary data from surveys of colonies on offshore oil and gas platforms to speculate on the scale of platform colonisation by kittiwakes and the potentially significant contribution this may make to the wider population. Practical Implication: We identify several research priorities to help address important evidence gaps and inform management strategies: (1) regular monitoring of offshore populations to inform national population censuses, (2) improved understanding of the ecological drivers of offshore breeding including selection of nesting sites and foraging habitats, fitness benefits and connectivity with onshore colonies and (3) collaboration with platform operators to develop practical approaches to minimise impacts of essential operational work on nesting kittiwakes.

Oil and gas platforms as artificial substrates for epibenthic North Sea fauna: Effects of location and depth

In this research, the environmental feasibility of a hybrid renewable source of wind‐solar energy has been assessed and the amount of this energy on offshore oil and gas platforms has been estimated in three basins of the Caspian Sea. Extractable wind‐solar energy around the Caspian oil and gas platforms was investigated using the Medium‐range Weather Forecast database by applying a resolution of 0.125° and a time step of 6 h for 10 years (2005–2014). The findings showed that the average wind energy in the northern, middle, and southern basins at the height of 10 m are 1.10, 0.89, and 0.43, respectively. Centralnoy field with an average energy of 2.398 MWh/m 2 .year is the most suitable oil and gas offshore platform for a hybrid application of wind‐solar energy. Inkie Moor field has the lowest amount of hybrid energy (1.432 MWh/m 2 .year) in the Caspian Sea.

Performance analysis of ocean thermal energy conversion system integrated with waste heat recovery from offshore oil and gas platform

This article presents results from the first detailed study on the feeding habits of fish assemblages associated with offshore oil and gas platforms in the North Sea. Multi-seasonal sam- pling was conducted at one of the oil platforms located in the central North Sea between Septem- ber 2010 and January 2014 to characterise temporal variation in the stomach contents of different fish species. A total of 6 fish species were recorded, including commercially important gadoids such as saithe Pollachius virens, haddock Melanogrammus aeglefinus and cod Gadus morhua. Saithe fed predominantly on euphausiids and haddock consumed a large proportion of ophi- uroids, whereas cod were mainly piscivorous. The prey compositions were significantly different between species, indicating the presence of interspecific prey resource partitioning among those species. To further investigate possible links between the feeding habits of the most dominant fish species, saithe, and the physical presence of offshore platforms across the North Sea, a separate set of stomach data was collected during the 2012 Quarter 3 International Bottom Trawl Survey aboard the FRV 'Scotia'. The multivariate analysis of both data sets showed that the observed spatio-temporal variability in the saithe diet was significantly explained by proximity to the near- est offshore platforms and changes in water temperatures, which appear to reflect patterns of euphausiid availability over space and time. The physical presence of the offshore structures may potentially affect the distribution/availability of zooplankton (i.e. euphausiids) and thereby influ- ence the feeding behaviour of saithe and any other marine populations that are interconnected to the dynamics of such trophic interactions.

In the offshore oil and gas fields, facilities decommissioning research has become a very important topic. The offshore oil and gas facilities should be deposit and abandon after stop production. This paper proposes decommissioning method of the offshore platform by studying this problem.

Retention of egress skills is critical during high-stress emergencies on offshore oil and gas platforms. This paper uses a virtual offshore platform to investigate the long-term retention of emergency egress competence. A two-phased empirical experiment was designed to first teach basic egress skills and subsequently assess skill retention. The first phase of the experiment used a simulation based mastery learning (SBML) pedagogical approach to teach 36 naive subjects the necessary spatial and procedural skills to evacuate safely from an offshore platform. In the second phase of the experiment, the same participants were tested after 6 to 9 months on their ability to respond to a series of egress test scenarios. These results indicated that emergency egress skills are susceptible to skill decay. Recommendations to improve the retention of offshore egress skills are discussed.

This article, written by JPT Technology Editor Judy Feder, contains highlights of paper OTC 28312, “Understanding the Global Scientific Value of Industry ROV Data To Quantify Marine Ecology and Guide Offshore Decommissioning Strategies,” by D.L. McLean, University of Western Australia; P. Macreadie, Deakin University; D.J. White, University of Southampton and University of Western Australia; P.G. Thomson, University of Western Australia; A. Fowler, New South Wales Department of Primary Industries; A.R. Gates, National Oceanography Centre, UK; M. Benfield, Louisiana State University; T. Horton, National Oceanography Centre; D. Skropeta, University of Wollongong; T. Bond, University of Western Australia; D.J. Booth, University of Technology, Australia; E. Techera, C. Pattiaratchi, and S.P. Collin, University of Western Australia; D.O.B. Jones, National Oceanography Centre; L. Smith, Woodside Energy; and J.C. Partridge, University of Western Australia, prepared for the 2018 Offshore Technology Conference Asia, 20–23 March, Kuala Lumpur. The paper has not been peer reviewed. Copyright 2018 Offshore Technology Conference. Reproduced by permission. Remotely operated vehicles (ROVs) are used by the offshore oil and gas industry to monitor the integrity of subsea infrastructure and, in doing so, collect terabytes of video and in-situ physical data from inaccessible regions and poorly understood marine environments. The complete paper describes the potential global scientific value of video and other data collected•by ROVs. ROVs and the Offshore Oil and Gas Industry Nearly one-third of global production of oil and gas is sourced offshore. Tens of thousands of offshore wells have been drilled, and more than 900 large-scale offshore oil and gas platforms have been installed. The offshore industry relies on underwater observation, control, and intervention, tasks performed increasingly by ROVs; over 700 were in operation globally at the time the paper was written. The advancement of ROV technology for the industry was prompted in the 1970s by developments extending into water depths beyond the capabilities of divers, and by the desire to reduce reliance on diving operations. Modern ROVs fall into two main classes: work class and observation class. A work-class ROV is car-sized, usually cuboidal, with a buoyant upper part containing power equipment, thrusters, manipulators, and cameras. An umbilical connection to the surface vessel provides electrical and fiber-optic connections that allow control and data transfer. Observation-class ROVs are smaller—sometimes briefcase-sized—with limited power and manipulation capabilities, and are used primarily for inspection purposes. For observation missions that can be conducted without real-time intervention, autonomous underwater vehicles (AUVs) are increasingly popular. These are generally torpedo-shaped, with higher hydrodynamic stability than ROVs, and can offer a similar image-gathering platform. Oil and gas projects and other ocean-based industries such as offshore wind use ROVs at multiple stages in a project’s life. Surveys of the region before installation or construction are conducted using ROVs or AUVs to identify the bathymetry and substrate conditions for hazard assessments and to provide parameters for engineering design. Drilling activities commonly involve ROV monitoring at the seabed level, and, when the production facilities are installed, ROVs are used to perform observation of all subsea activities. During operation of a project, ROVs are used for inspection and intervention. The manipulators operate valves and interchange components, and, if required, can undertake cutting. Inspections include visual surveys as well as checking of anode electropotentials and clearance of marine fouling. Inspections commonly are undertaken annually but can be more or less frequent depending on risk level and maintenance requirements. In total, the ocean around a typical oil and gas development may be visited dozens of times by ROVs during the project’s life.

Complementary molecular and visual sampling of fish on oil and gas platforms provides superior biodiversity characterisation