**9. Examples of modeling sea gas-and-oil producing system (GOPS) processes**

There are many standards used in the oil and gas industry (ISO 10418 "Basic surface safety systems", ISO 13702 "Control & mitigation of fire & explosion", ISO 14224 "Reliability/maintenance data", ISO 15544 "Emergency response", ISO 15663 "Life cycle costing", ISO 17776 "Assessment of hazardous situations" etc.), but they focus on technical aspects and do not consider terrorist threats.

The principal difference of GOPS consists of the fact that safety problems should be resolved in the sea because long distances from the shore and probable ice conditions in northern regions exclude any help from the outside—see **Figure 13**.

Oil and gas are usually produced on stationary stills and concrete platforms located up to 200 km from the shore at the depth from several dozens to several hundred meters. There are nearly 5000 sea platforms dispersed all over the world. Dozens of thousand oil wells are drilled from these platforms. Produced oil is delivered to the buyers by tankers or directly through pipelines.

Produced gas before transportation goes into the liquefied natural gas terminals. After the liquefaction its volume reduces by 600 times, that makes its transportation profitable. Statistics shows that during the time of sea field development, emergencies are distributed in the following ways [10, 11]: drilling—32% (including 23% at survey and 9% at production

**Figure 13.** Some explanation of conditions for examples 6 and 7.

in the mountains. It's quite a profitable and secure project. It must be admitted that the level of security obtained—the risks are 0.35 in 10 years and 0.73 in 50 years—can be considered

Thus, the examples of forecasting the security operation of the pipelines have illustrated the ability to proactively manage risk. The effectiveness is not just using the universal models but also in the justification of the necessary system requirements for new materials (pipes should be intelligent with the ability of continuous monitoring and mean time of failure for at least a year) and in technologies of restoring functional integrity, in minimizing risks on the basis of the control parameters of the processes of control, monitoring and restoring even before promising technologies have appeared! It is therefore proposed to manage the risks for pipelines of the future even before their creation and based on this, to justify the technical

**1.** Rational control, continuous monitoring and prompt elimination of the revealed accidents and failures allow one to increase the safety tens of times compared to the lack of a systematic

**2.** With using advanced technology accidents and failures on plains it is possible to virtually

There are many standards used in the oil and gas industry (ISO 10418 "Basic surface safety systems", ISO 13702 "Control & mitigation of fire & explosion", ISO 14224 "Reliability/maintenance data", ISO 15544 "Emergency response", ISO 15663 "Life cycle costing", ISO 17776 "Assessment of hazardous situations" etc.), but they focus on technical aspects and do not

The principal difference of GOPS consists of the fact that safety problems should be resolved in the sea because long distances from the shore and probable ice conditions in northern

Oil and gas are usually produced on stationary stills and concrete platforms located up to 200 km from the shore at the depth from several dozens to several hundred meters. There are nearly 5000 sea platforms dispersed all over the world. Dozens of thousand oil wells are drilled from these platforms. Produced oil is delivered to the buyers by tankers or directly through pipelines. Produced gas before transportation goes into the liquefied natural gas terminals. After the liquefaction its volume reduces by 600 times, that makes its transportation profitable. Statistics shows that during the time of sea field development, emergencies are distributed in the following ways [10, 11]: drilling—32% (including 23% at survey and 9% at production

excludes, and in the jungles and mountains to reduce of their number many times.

**9. Examples of modeling sea gas-and-oil producing system (GOPS)** 

as normative "acceptable."

74 Probabilistic Modeling in System Engineering

**Summary for Example 5**:

control and monitoring!

consider terrorist threats.

**processes**

requirements to the system and their components.

regions exclude any help from the outside—see **Figure 13**.

drilling); gas-and-oil production—19%; ship collision and towing of floating drilling rigs and blocks for platform construction —14%; storms—11%; floating drilling rigs' delivery to the point of drilling—6%; and other kinds of works—18%.

A safety policy concerning sea GOPS safety includes accident prevention and drawing, plans concerning failure consequences of liquidation and actions taken in case of emergencies. Special brigades are formed and trained to prevent and liquidate failure consequences. Highquality materials and pipes and application of computer diagnostics for pipe integrity monitoring provide safety of the GOPS operation.

All safety measures undertaken nowadays provide system protection from inexperienced personnel (because according to statistics about 80% of all failures are connected with the human factor) or from the natural causes and "cataclysms" which are of an unpremeditated character. However, the attitude to safety cardinally varies in case of terrorist threats because terrorist actions are malicious and aimed at damaging the system through its vulnerable "bottlenecks." As a result the existing risks of system safety violation essentially grow.

The examples 6 and 7 are devoted to modeling processes of possible terrorist influence and GOPS safety provision (including platforms, coastal technological complexes including terminals for floating storage and offloading, liquefied natural gas terminals, pipelines, tubing stations) and to withdraw quantitative evaluations of their vulnerability in various scenarios.

Example 6: connected with an estimation of effectiveness of a safety monitoring system for sea GOPS. Before we start the analysis of possible terrorist threats, let us consider the basic dangers that can arise on sea platforms in case of failures. They are explosions of fuel-air mixed clouds; generation and burning of fire balls; oil spill and burning; separation and spread of technological equipment parts; and others. Each of these dangers can aggravate consequences of failures, that is, lead to the "dominoes" effect. To control risks the following measures are taken: application of safe technologies; measures preventing dangerous situations; applications of systems providing early detection of emergencies; control over operating parameters of the technological process, the signal system and the notification about emergency technologies; measures directed on mitigation of emergency consequences; and preparation of a platform staff to react immediately.

day. The high level of GOPS protection in emergencies is mainly provided by application of

Probabilistic Modeling Processes for Oil and Gas http://dx.doi.org/10.5772/intechopen.74963 77

Against the background of proved measures of counteraction to sources of emergency the situation concerning the struggle against terrorist threats appears to be cardinally worse because this problem is still at the initial stage. Other things being equal, let us estimate the expected sea GOPS protection from terrorist threats with differences in abilities of a security service operator to reveal suspicious actions and objects which can be a means of terrorist purpose realization.

Example 7: Let the deliberately formal conditions of a terrorist influence scenario be similar to the emergency dangers in example 6. Let us suppose that for providing protection of sea GOPS platforms from terrorist threats, any of the protecting technologies are used. Let the scenario of the potentially dangerous influence of terrorists provide the frequency of a danger source appearance from air, the water table or from under water equal to 1 time per 24 h with the mean time of activation after penetration onto a platform equal to 1 h. The time between the termination of the previous and the beginning of the following diagnostics taking into consideration the broken integrity recovery is 2 h. Let us assume the mean continuous time of potentially faultless operators' works in each shift to be 6 hours. It is required to evaluate the safety of the sea platform operation in such scenarios within several hours, days, weeks and a month.

The integrated calculation results prove that without any additional protection the system remains in safety with the probability of 0.9 only within 2–3 h. It is explained by a comparative rarity of a danger source appearance. If the 1st technology of counteraction to terrorists is applied (this technology exists on the most of platforms and implies visual tracking of air conditions, the working hours what is an equivalent to the case if there are no measures of

If the most effective second technology is used, the probability of GOPS integrity within a day is more than 0.92, that is, the risks of latent introductions of a terrorist danger source into a system and the overcoming of all technological protection barriers preventing realization of terrorist threats in the conceived volume approximate to 0.08. At the same time to provide the required safety within a month in conditions of daily danger that a sudden terrorist attack happens, this risk runs up to 0.93. The main cause of this is insufficient preparedness of operators to recognize terrorist threats at the background of other technical threats. That's why it is necessary to increase the mean time between failures of a safety service operator to tens and hundreds of hours what requires creation of special "smart subsystems" in order to support operator functions (radartracking, optical, acoustic, electromagnetic means etc.). Compare the results of examples 6 and 7.

**Pragmatic interpretation of example 7 results**: If the characteristics of terrorist dangers growing are similar to the characteristics of emergency danger, the risks of terrorist threats' realization in the conceived volume are incommensurably higher. Owing to insufficient preparedness and technical equipment of operators for timely and valid recognition of terrorist threats at the background of other technical threats, a variety of GOPSes are completely help-

approved automatic safety technologies.

counteraction to terrorists on a platform at all.

less in case of terrorist dangers that are growing.

The analysis shows that the basic preventive mechanism of risk reduction is safety monitoring in various variations of its application. Let us estimate commonly used safety technologies, technology 1 (periodical diagnostics of system integrity without the continuous monitoring between diagnostics) and technology 2 (continuous monitoring between periodical diagnostics is added to technology 1)—see Section 4.

Let's estimate efficiency of sea GOPS safety technologies used in the case of emergencies for dozens of years. Thus we take into account that the basis of safety systems consists of automatic facilities' mean time where failures of which are estimated for several years.

To form inputs for probabilistic modeling the arising of basic dangers for sea platforms in the case of failures is considered. There is generally one of the abovementioned technologies to provide safety of GOPS components (platforms, coastal technological complexes including floating storage and offloading terminals, liquefied natural gas terminals, pipelines, tubing stations). The script of emergency development provides frequency of danger source appearance equal to 1 time per 24 h with a mean time of activization within an hour. Time between the termination of the previous and the beginning of the next diagnostics taking into account broken integrity recovery is 2 h. Let us suppose that monitoring is performed by automatic means of tracking the integrity of system components. To such means systems of fire and gas detection, systems of water fire-fighting and foaming, circled fire mains, systems of platform irrigation, pressure relief systems, emergency switching of systems, various locking device and so on may be related. Let the mean time between failures of these means be not less than 2 years.

It needs to estimate a safety of the sea platform operation in such scenarios within several hours, a day, several weeks and a month.

The integrated results of calculations prove that at the realization of technology 1, the required safety is provided only for several working days—what is inadmissible in practice. If the most effective technology, technology 2 is realized, the probability that a dangerous influence does not occur within 24 h is above 0.99997, that is, the probability of emergency is about 0.00003. At the same time provision of the required safety within a month in conditions of daily failure danger this risk increases up to 0.001 that also appears to be a practically admissible result.

**Summary for example 6**: An effectiveness of the existing safety systems of sea GOPSs appears to be rather enough or high if the frequency of danger source appearances is about once a day. The high level of GOPS protection in emergencies is mainly provided by application of approved automatic safety technologies.

clouds; generation and burning of fire balls; oil spill and burning; separation and spread of technological equipment parts; and others. Each of these dangers can aggravate consequences of failures, that is, lead to the "dominoes" effect. To control risks the following measures are taken: application of safe technologies; measures preventing dangerous situations; applications of systems providing early detection of emergencies; control over operating parameters of the technological process, the signal system and the notification about emergency technologies; measures directed on mitigation of emergency consequences; and preparation of a

The analysis shows that the basic preventive mechanism of risk reduction is safety monitoring in various variations of its application. Let us estimate commonly used safety technologies, technology 1 (periodical diagnostics of system integrity without the continuous monitoring between diagnostics) and technology 2 (continuous monitoring between periodical diagnos-

Let's estimate efficiency of sea GOPS safety technologies used in the case of emergencies for dozens of years. Thus we take into account that the basis of safety systems consists of auto-

To form inputs for probabilistic modeling the arising of basic dangers for sea platforms in the case of failures is considered. There is generally one of the abovementioned technologies to provide safety of GOPS components (platforms, coastal technological complexes including floating storage and offloading terminals, liquefied natural gas terminals, pipelines, tubing stations). The script of emergency development provides frequency of danger source appearance equal to 1 time per 24 h with a mean time of activization within an hour. Time between the termination of the previous and the beginning of the next diagnostics taking into account broken integrity recovery is 2 h. Let us suppose that monitoring is performed by automatic means of tracking the integrity of system components. To such means systems of fire and gas detection, systems of water fire-fighting and foaming, circled fire mains, systems of platform irrigation, pressure relief systems, emergency switching of systems, various locking device and so on may be related. Let the mean time between failures of these means be not less than 2 years.

It needs to estimate a safety of the sea platform operation in such scenarios within several

The integrated results of calculations prove that at the realization of technology 1, the required safety is provided only for several working days—what is inadmissible in practice. If the most effective technology, technology 2 is realized, the probability that a dangerous influence does not occur within 24 h is above 0.99997, that is, the probability of emergency is about 0.00003. At the same time provision of the required safety within a month in conditions of daily failure danger this risk increases up to 0.001 that also appears to be a practically

**Summary for example 6**: An effectiveness of the existing safety systems of sea GOPSs appears to be rather enough or high if the frequency of danger source appearances is about once a

matic facilities' mean time where failures of which are estimated for several years.

platform staff to react immediately.

76 Probabilistic Modeling in System Engineering

tics is added to technology 1)—see Section 4.

hours, a day, several weeks and a month.

admissible result.

Against the background of proved measures of counteraction to sources of emergency the situation concerning the struggle against terrorist threats appears to be cardinally worse because this problem is still at the initial stage. Other things being equal, let us estimate the expected sea GOPS protection from terrorist threats with differences in abilities of a security service operator to reveal suspicious actions and objects which can be a means of terrorist purpose realization.

Example 7: Let the deliberately formal conditions of a terrorist influence scenario be similar to the emergency dangers in example 6. Let us suppose that for providing protection of sea GOPS platforms from terrorist threats, any of the protecting technologies are used. Let the scenario of the potentially dangerous influence of terrorists provide the frequency of a danger source appearance from air, the water table or from under water equal to 1 time per 24 h with the mean time of activation after penetration onto a platform equal to 1 h. The time between the termination of the previous and the beginning of the following diagnostics taking into consideration the broken integrity recovery is 2 h. Let us assume the mean continuous time of potentially faultless operators' works in each shift to be 6 hours. It is required to evaluate the safety of the sea platform operation in such scenarios within several hours, days, weeks and a month.

The integrated calculation results prove that without any additional protection the system remains in safety with the probability of 0.9 only within 2–3 h. It is explained by a comparative rarity of a danger source appearance. If the 1st technology of counteraction to terrorists is applied (this technology exists on the most of platforms and implies visual tracking of air conditions, the working hours what is an equivalent to the case if there are no measures of counteraction to terrorists on a platform at all.

If the most effective second technology is used, the probability of GOPS integrity within a day is more than 0.92, that is, the risks of latent introductions of a terrorist danger source into a system and the overcoming of all technological protection barriers preventing realization of terrorist threats in the conceived volume approximate to 0.08. At the same time to provide the required safety within a month in conditions of daily danger that a sudden terrorist attack happens, this risk runs up to 0.93. The main cause of this is insufficient preparedness of operators to recognize terrorist threats at the background of other technical threats. That's why it is necessary to increase the mean time between failures of a safety service operator to tens and hundreds of hours what requires creation of special "smart subsystems" in order to support operator functions (radartracking, optical, acoustic, electromagnetic means etc.). Compare the results of examples 6 and 7.

**Pragmatic interpretation of example 7 results**: If the characteristics of terrorist dangers growing are similar to the characteristics of emergency danger, the risks of terrorist threats' realization in the conceived volume are incommensurably higher. Owing to insufficient preparedness and technical equipment of operators for timely and valid recognition of terrorist threats at the background of other technical threats, a variety of GOPSes are completely helpless in case of terrorist dangers that are growing.
