Файл: Диссертация удк 622. 692 053048. 34 Студент Группа фио подпись.docx

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In order to determine the state of the pipeline, a technical diagnosis is carried out, which uses methods that determine the state of the facility, and develops a strategy for preventing and responding to emergencies.

The level of reliability of the pipeline during operation depends not only on the measures used to improve reliability at a given time, but also on the design and construction of the pipeline. Accordingly, the objectives and reliability requirements are implemented throughout the life cycle of the pipeline. Let us consider the challenges facing the people to ensure concerning the required level of reliability at different stages of life of the pipeline.

Project stage. At this stage, initial reliability indicators of oil pipelines are set taking into account technological features and design schemes of individual elements and pipeline sections [4]. Also, the materials are taken into account, the ways are provided to increase the reliability and durability of oil pipelines in typical environmental conditions. At the design stage, standards are developed.

Construction phase. At this stage, the tasks associated with the development of methods for technological control of construction and installation works and methods for conducting pre-start tests of the linear part with increased pressure for finding production defects are solved.

Operation phase. At this stage, there are problems related to the development of methods for determining the technical condition of oil pipelines and maintaining the reliability properties formulated in stage of projecting, with the development of methods for ensuring reliability.

The operational phase includes the collection and processing of statistical data on the reliability of individual elements of pipeline systems, as well as failures and damage, construction of reliability models for pipeline systems, the identification of failure laws and recovery times, the development of reliability methods, methods for calculating system reliability indicators, developing basic criteria and forecasting [4].

Let us consider in detail the operational phase of the pipelines.

The initial stage of the operation pipeline according to the criterion of reliability is the research stage, containing functions for analysis and forecasting.

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As a result of the reliability analysis, the reasons for success and failures in managing the pipelines in the past and present, the patterns and factors of future development, taking into account technical, technological and financial capabilities are obtained.

The reliability prediction, which is based on the analysis, is the final element of the research stage. The results of the forecast include the statement of objectives and the likely time frames for their achievement (the prediction of the search), probabilistic evaluation of the technical, technological and financial resources needed to achieve using various ways or paths (the normative prediction) [19].

The search forecast determines the probability of achieving goals or status of the object, i.e. it predicts the future, starting from the existing level of test object prediction.

The content search predicts reliability pipeline in terms of the residual life of pipeline sections or the entire pipeline, starting from the existing level and modes of the object prediction.

The regulatory forecast begins with the formation of the main goal, usually determined at the stage of the search forecast. Then, this goal consistently outlines the steps of implementation. At the same time, all organizational, technical, technological and financial resources and activities which are required to provide various ways to achieve the main goal are also considered. In accordance with this, the regulatory forecast reflects the necessary needs (resources, measures, etc.) and has an orientation from the future to the present [19].

The content standard projection of the reliability of pipelines is to determine ways and means necessary to ensure reliability, safety commission modes in order to achieve the designated target. Graphical interpretation of the search (1) regulatory and (2) the prediction is shown in figure 3.

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Figure 3 - Graphical interpretation of the search (1) and normative (2) prediction,

where t_ост – residual resource, t_н – assigned resource.

Note that the gap between

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t_ост and t_н is due to the following circumstances:

1. 
   the residual resource is estimated roughly because the resource is generally a random value;
   
2. 
   for oil pipelines in which the achievement of the ultimate state can be accompanied by especially severe consequences (irreparable material damage, threat of violation of ecological balance, etc.), as well as inadequate means and methods for monitoring the technical condition of oil pipelines and predicting their residual resource determine the longevity index – assigned resource. The assigned resource is in fact a certain fraction of the remaining resource.
   

It is clear that on the basis of scientifically-based complex prediction, including the search and regulatory stages, it is possible to match capabilities and needs. In case of discrepancies of needs and the purposes to be achieved, the necessary predictive element of research is the study of preventive and protective measures representing organizational, technical, technological and financial programs.

The choice of the forecasting method is significantly influenced by the period for which the forecast is developed. This time interval, called the prediction forecast period, should be linked to the designated resource, which will, in the future, unite environmental and technical solutions. Depending on the period of anticipation, forecasts can be subdivided into monthly (up to 1 month), annual (up to 1 year), medium-term (up to 3 years), long-term (more than 3 years) [19].

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Forecasts precede the decision-making phase, which includes program development and planning. The program contains a system of goals, rational ways to achieve them and the resources required. At the same time, the quantitative characteristics and the timing of the goal fulfillment are, as a rule, are predictive. The scheduled tasks, specific deadlines and executors, as well as limited resources are developed on a sub-stage of planning, which is at the end of the decision-making stage. The plan does not contain any probabilistic estimates. The next step in the process of managing the operation of the oil pipeline is the implementation, which contains the functions of general management and operational control.

The implementation of the functions of the general management consists mainly in coordination of works on implementation of the plan. Operational management involves the following actions: counting; control; determination of the impact of current deviations identified during accounting and control in terms of deadlines, costs and efficiency; development of set of measures on elimination of deviations.

The concept of pipeline operation management for the assigned resource is based on the following provisions:

• 
  implementation of a comprehensive reliability analysis;
  
• 
  conducting normative forecasting and determining technical strategies for achieving the assigned resource;
  
• 
  program-target planning through evaluation procedures to monitor pipeline performance and safety;
  
• 
  coordination of system and local solutions at the level of the control system and the controlled system on the basis of the inverse connection [19].
  

Development and reconstruction stage. At this stage, a particularly important consideration of the reliability with the greatest economic efficiency is carried out. Phase of development and the reconstruction partially combines the first three stages of the life cycle of pipelines. At this stage, the following main tasks are addressed:

• 
  determining the necessary level of reliability of pipeline systems;
  
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  ensuring a predetermined reliability of pipeline systems;
  

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