Ensuring Safety of Gas Field Infrastructure Using ALARP and a Systematic Approach

Abstract

   Introduction. A significant part of the global and state economy is the production and supply of hydrocarbon raw materials. The issues of safety in this area will remain important in the coming decades. The problem is actively discussed in the professional and scientific community. Theoretical and applied works are published. Local, point-based methods are calculated and implemented, which allow predicting and preventing emergencies in certain units of the considered objects. At the same time, there are no sufficiently justified and reproducible system solutions that can take into account the state of, for example, oil or gas field as a single complex and act as indicators not only of ordinary local accidents, but also of systemic accidents — catastrophes. Such a scientifically and experimentally based solution is described in this article. The approach is proposed as part of the formation of a comprehensive scientific and technical program (CSTP) to ensure the safety of natural and technogenic objects (NTO).   The aim of this work was to describe the practice of its application in the conditions of specific gas fields and to justify the refusal to focus on solutions that took into account only the minimum practically acceptable risk, that is, built on the ALARP principle (as low as reasonably practicable).   Materials and Methods. The article was based on the results of field tests of natural and technogenic objects (NTO) of the oil and gas complex — the Yuzhno-Russkoye field of OJSC Severneftegazprom (SNGP), LLC Gazprom Dobycha Yamburg (GDYA) and the gas pumping station (GPS) Orlovka-2 (Ukraine), conducted with the authors’ participation. Significant results were obtained and evidence-based physically interpreted during acceptance tests of an explosion-proof certified, created under the guidance of the authors of a prototype of a disaster response system (DRS) at the integrated gas treatment plant (IGTP) in LLC GDYA in 2006. At the same time, for the first time in the world practice, the fact of early detection and parrying without consequences by means of DRS on the UKPG-2 of the development of a large-scale general industrial disaster was confirmed. In the form of graphs, the revealed patterns of NTO have been visualized, which made it possible to form harbingers of the development of accidents and catastrophes at the NTO of LLC "GDYA", SNGP and GPS "Orlovka-2". Information on the high experimental reproducibility of the obtained results was presented. The technology has been developed of early detection and parrying of all types of potentially dangerous self-exciting systemic phenomena on real NTO infrastructure — self-oscillations. Three cases of their excitation in real gas fields were presented.   Results. The paper shows the fragmentary nature and locality of emergency protection systems based on the ALARP principle. The consequence of this was its complete unsuitability for early detection and counteraction to the most large-scale and costly system accidents — catastrophes that were multifactorial processes, in which none of the factors was decisive. The alternative complex solution of the problem proposed by the authors and brought to working condition was based on a system approach adapted to the NTO of the oil and gas complex. The measured parameters of various NTO infrastructure — fields of LLC "GDYA" and SNGP were processed and analyzed at the moments of development of self-oscillating modes on them, due to self-sustaining nonlinear mechanisms of interaction of NTO elements with constant (non-oscillatory) sources of energy replenishment. Three such modes of self-excitation were illustrated. The most informative in this case were the transient modes of operation of the equipment. According to the technologies experimentally developed by the authors, the areas of critical operating modes of equipment with pronounced potentially dangerous bifurcation points were analyzed. The result of superimposing treatments of the measured parameters of eight full-scale tests of NTO — graphs of dimensionless amplitude-frequency characteristics of the interconnections of a real dynamic system was presented: "input — gas cooling housing" → "output — pipe casing" at the frequency of self-oscillations.   Discussion and Conclusion. The capabilities of ALARP did not meet the tasks of system monitoring of the occurrence and development of dangerous incidents in gas fields. This conclusion can be attributed to all standard sizes of NTO infrastructure in Russia. Fundamentally different solutions should be used to ensure comprehensive observability, controllability, and safety of NTO. A comprehensive scientific and technical program is recommended: "Innovative hardware and software tools and technologies to ensure the observability, controllability, and safety of the NTO infrastructure of Russia".