(71f) Assessment of Reliability and Risk at Dynamic Systems: A Discussion of Social-Technical Factors in the Exploration and Production of Oil at Pre-Salt Layer - Brazil

INTRODUCTION

Economically and historically, the world and its economy have been dependent on different commodities. The existence of one of the most used nowadays, oil, precedes the modern times. In its constitution are mainly organic compounds, as hydrocarbons of various molecular weights, accumulated miles and miles beneath the earth.

Currently, the extraction of oil is one of the largest and most important activities in the world. This is due to its high use in several applications, such as LPG (Liquefied Petroleum Gas) or cooking gas, gasoline, kerosene and thousands of other plastics products we may find in our daily activities.

However, this is a non-renewable resource, so more and more efforts are being made towards finding oil and its extraction from underground. More recently, a large reservoir was discovered, situated at distance from the coast and depth never explored before, as it is referred to, the Brazilian Pre-salt layer.

Undifferentiated of any exploration activity, extraction and transportation of oil from seabed offer risks. There are tools available for qualitative and quantitative risk assessment. In order to be effective and successful, the analysis of these risks must include the understanding of dynamic socio-technical factors, since it is necessary to deal with enormous challenges when it comes to extracting the oil. Some challenging issues are: extreme conditions of temperature and pressure at high depths, abrupt climate changes, salt layer drilling technologies, personnel logistics, as in moving staff in and out of the platforms.

THE DEVELOPMENT OF RISK ANALYSIS

The need for analyzing the risk of operations and its consequences came about through an evolution of thought. Originally, long ago, the one and only factor that guided the production of a good or service was intuition. Products were made by hand, in such way that imperfections and defects were accepted, since they do not prevent the product, from reaching their ultimate purpose.

Over the course of time, it was noticed that improvements could be made by adding knowledge to the process. This knowledge provided the creation of design patterns. Thus, it was possible to map the failures and trace projections of expected impacts. However, the association of intuition with knowledge did not, by itself, put an end to/mitigate the consequences of general accident, from that moment on, another variable was included in the matter, risk analysis. With the evidence of this new need, design technics and risk analysis were developed, highlighting techniques to quantify the risk based on frequency of failures and severity of impacts, based on expert opinions. Also, the category of risk of each activity was evaluated and estimated so that protections could be provided for the most dangerous operations.

THE QUALITATIVE TOOLS

Tools such as Process Hazard Analysis (PHA), Hazards and Operability Study (HAZOP) and Qualitative Fault Tree are used to evaluate and estimate the impacts of production. However, it was noted that such impacts differ, in some circumstances, of the actual impacts. These information were archived in databases. The gathering of this information enabled the introduction to reliability studies. In other words, reliability means the ability of items or systems of maintaining their expected function, in a given period of time. Progresses in this direction have been made through the development of tools such as Vulnerability Study, Reliability Study, Failure Mode and Effects Analysis (FMEA), Quantitative Fault Tree and Layer of Protection Analysis (LOPA). Regarding that direction, adjustments to the risk analyzes were incorporated, confirming or readjusting frequency and severity of events evaluated in previous qualitative assessments.

FAILURE MODE ANALYSIS AND RELIABILITY

Nowadays, the matter of reliability is vastly discussed and mentioned. The economical global situation implies, more and more, quick changes and effective adaptations in order for a company to maintain a strong competitive status inside its market. The maintainability of this competitiveness, by nature, brings obvious and rigorous consequences: the need to generate more revenue by using less and less resources. Regarding that train of thought, enters the concept and use of reliability, which, according to MOUBRAY, 2000, is the ability of an item or system to maintain its original purpose intact, for a given period of time, under given circumstances, improving process safety, durability and productivity. Situations in which people and machinery do not perform satisfactorily tend to represent extra costs, that may or may not fit the project's budget, which jeopardizes the company's image and performance before the competitors and clients, that, evidently, are becoming more and more exigent. 

QUANTITATIVE ANALYSIS 

On the other hand, despite the development in the field of quantitative risk assessment, it has been noted that the estimated impacts differ from the real ones, which drove the studies to the conclusion that the problem was in making the assumption that all economic systems are controlled and constant, but, they are definitely not.  According to RASMUSSEN, 1997, the further understanding of how risk assessment works involves the comprehension of the dynamic-environment complexity, in such a way that human, organizational and environmental factors are considered in the analysis. 

THE DINAMIC FATORS

Dynamic factors represent a large influence on reliability analysis, which means they also impact on the probability of a failure event. Conforming with RASMUSSEN, 1997, It is extremely important to take into account the dynamic risk, in innumerous occasions. In that previously mentioned unstable scenario is where almost - or absolute all -operations take place, and, by considering it, one is able to deal more efficiently with uncertainties and undesirable situations. 

Climate changes and human factors are common examples of the dynamism faced by companies, on their operational activities. The more one comprehends how these elements effect the system, the more it is possible to minimize the difference between the estimated and real impacts. Therefore, this is a matter of unquestionable importance for companies that wish to improve their performance.

THE CASE STUDY, THE BRAZILLIAN PRE-SALT OIL

During this study case, it is pretended to discuss the dynamic aspects of reliability and risk associated to the petroleum extraction and exploration, in Brazilian Pre-salt. This region is referred to as the biggest oil reservoir discovered in the last ten years, and it is located three hundred kilometers from the coast, reaching a eight-kilometer depth, in the middle of the ocean. The exploitation of this oil is of a great challenge to those who make plans and efforts to do so, because it involves extreme circumstances never dealt with before, not to mention that it demands the newest and state-of-the-art technologies.

Firstly, when it comes to offshore exploration, there are certain known, but not less complicated, difficulties, such as: the choice of what material to use in ducts that transport the oil up to the platform, in order to hold against severe conditions; the oil upstream control system; the complete logistics of people and necessities in and out of the platform and, evidently, personnel training to avoid accidents.

Advanced and modern knowledge are needed for the risk analysis of the enterprise, due to a more stressful environment and more demanding structures, regarding seas operations. It is important to discuss the environmental conditions in the salt layer after its penetration to assess the possibility of a plastic deformation due to higher temperatures and pressure levels. Another important discussion is the one concerning oil-leakage containment technologies in high seas and the assessment of the consequences to avoid another disaster event, like Horizon (BP). In order to treat and overcome emergency situations with that kind of distance from the coast, it is necessary to establish the right transportation mode and more suitable local rescue facilities to mitigate the effects of possible future events. Specialists say that it takes one day and a half for the leakage-containment support team to get to the ships.

The necessary training and emergency simulation, in high seas, are highly difficult. They demand high simulation technologies and approximation to catastrophic situations ( with the discussion of evasion of installation). The exploration team faces the challenge of working with high temperature and pressure levels variation in the depths of the ocean, which certainly impacts the environment. 

This kind of process deals with a larger amount of inflammable products, which, definitely, increases the risk of explosion, especially because it comes to ships and platforms. This risk can be maximized by socio-technical dynamic factors, such as: vastly multicultural staff with a great possibility of communication problems; onboard workers performing activities that cause extra stress creating an inclined environment towards human or managing errors.