## Tag Archives: diagnostics

## SAFETY OF TECHNOLOGICAL PIPELINE SYSTEMS AT THE ENTERPRISES OF THE OIL AND GAS COMPLEX

Industrial safety of modern enterprise of oil and gas industry is in a great deal determined by operating reliability of dangerous productive objects most representative from that are pipelines of the system. According to the Federal law “About industrial safety of dangerous productive objects”, these objects behave to the dangerous productive objects and require enhance able attention to providing of their reliability and faultlessness.

One of important on meaningfulness factors resulting in emergency situations and refuses of pipelines is an increase of amount of damages in the metal of pipes, during the protracted exploitation of technological pipelines and thinning of walls of pipes.

Accidents of technological pipelines are attended with explosions, fires, losses of hazardous and harmful substances, able to form explosive mixtures, render the toxic affecting personnel and environment.

Principal reason of refuses of technological pipelines is internal corrosion under the action of the aggressive pumped over products. In this connection the decision of problem of increase of safety of exploitation of technological pipelines in a great deal depends on efficiency of facilities of anticorrosion defence.

The basic methods of fight are offered against corrosion of the oil-field equipment, that apply domestic and foreign companies today. They can be divided into next groups: chemical, physical, protector defence.

The basic requirements over, produced to functioning of the pipeline systems of oil and gas complex, are brought is safety, high reliability and efficiency of exploitation. Providing the brought requirements over can be attained due to upgrading of technical diagnostics and management by monitoring of exploitation pipeline.

In the article the review of basic methods of corrosion protection is produced and requirements are set forth to providing of industrial safety during exploitation of technological pipelines.

## ESTABLISHMENT OF CONCRETE DEPENDENCE OF DEPTH SOUNDING OF THE DISTANCE BETWEEN SEEKERS

One of today’s most popular building material is concrete. This building material is not only well-known and commonly used, but also time-tested. And concrete building and high-rise buildings with their huge loads on the base and the shell of atomic reactors and storage of toxic waste. However, latent defects in concrete and reinforced concrete structures can be fatal and lead to serious economic, environmental and even humanitarian losses.

Most often, the defects of constructions and structures are not caused by one factor, but as a result of their total effect, with a marked influence of any factor may cause increased effects of other factors. Defects found during the survey are divided into the following groups in order of importance: the defects that lead to the reduction and loss of load-carrying capacity; partially reducing the bearing capacity with a change in geometric dimensions; deviations in the geometrical dimensions while maintaining load-carrying capacity, causing unfitness for technical operation. Durability and stability of building structures depends quality of elements made of concrete or reinforced concrete.

In practice, there is often a concrete examination methods cannot be used for in-depth assessment of quality of concrete structures for various reasons: because of the lack of bilateral access for measurement, because of the cramped conditions, inability to use destructive methods of control and need to be adapted to the conditions of the construction site with taking into account the structure of a particular product.

This paper proposes a method for increasing the depth sounding at Concrete pipe coating by changing the distance between the points of acoustic contact. On the basis of experimental data derived from the dependence of the sensitivity of the instrument sounding base. Changing the design of the device holding the cone transducers, and the proposed scheme preliminary marking the concrete surface to minimize unexplored areas of concrete in a controlled area and increase the ka-operation control operations and thereby improve the reliability of the structure under construction.

## METHODS OF CALCULATION OF AN OPERATING MODE OF DIFFICULT MAIN GAS PIPELINES

The main gas pipelines are the body of the gas transmission system. The main share of expenses of energy resources in the pipeline transport of gas belongs to this part of the system. Characteristics of the pipeline network, also as the set technological tasks, are defining factors for an operating mode of other equipment of system which settles down generally at compressor stations.

In this regard, it is very important to provide possibility of calculation of an operating mode of the main gas pipeline with sufficient degree of accuracy. For this purpose you have to consider all significant factors which influence operation of the main gas pipeline. The method of calculation shouldn’t contain insoluble difficulties of mathematical character.

In spite of the simple construction of the gas pipeline at first sight, it contains difficult processes of movement, friction, interaction with gravitation, internal and external heat exchange. These processes, as a rule, change in time therefore they are non-stationary.

The gas transmission system has the difficult scheme where simple gas pipelines are united in a transport network, the operating mode of all elements is interconnected.

The specified complexity of processes has rather difficult mathematical description of all these processes by means of the corresponding models, in this regard; obtaining decisions is accompanied by difficulties of mathematical character. Simplification of models for the avoidance of the specified difficulties can reduce their compliance to the described object.

The author of this work considers existing methods of calculation of simple gas pipelines, does their analysis.

The author classifies models concerning a scope.

The author revealed construction stages for all considered universal models.

By results of the research the author draws a conclusion about the necessity of the solution of the question of mathematical modeling of gas movement in the main gas pipeline and notes the productive directions of further researches of this subject.

## ASSESSMENT OF CALCULATING ERRORS OF A NON-STATIONARY OPERATING MODE OF THE GAS PIPELINE

The author of this work offers the way of definition of the internal calculating error of methods of the gas pipeline hydraulic calculation. The offered way is applicable both to stationary model, and to the most general case – to the model describing non-stationary process. This way is shown on the calculation of the known system of the equations which describes non-stationary process by “the way with variable coefficients”. But this way of calculation was considerably modified by the author for the accounting of heat exchange, and for gravity influences. But this way of calculation was considerably modified by the author for the accounting of heat exchange, and for gravity influences. The initial “way with variable coefficients” didn’t consider these factors that attracted considerable errors. The mentioned adjustment is described in detail by the author in the other publication. The offered way of definition of the internal calculating error of methods of the gas pipeline hydraulic calculation includes the analysis on each component of the initial equation of movement of compressed liquid. The author gives formulas for definition of influence of all factors entering this equation. The main thing of definition of an internal calculating error is the comparison of the sum of influence from all factors which sizes are received as a result of calculation for the chosen method with basic data for the same calculation. These data are provided to a uniform scale for possibility of carrying out procedure of comparison. As such scale the size of change of gas pressure in the course of its movement on the gas pipeline is accepted. The author defines changes of pressure according to the following factors: change of gas energy in volume because of not stationarity of process, change of kinetic energy of gas, influence of friction forces and weight. The sum of changes of all these factors pressure is compared with the general pressure difference on the gas pipeline that is set in basic data of calculation. Their distinction defines an internal calculating error of the estimated method. The offered way is shown on calculation of the concrete example. The author shows settlement ratios for all counted parameters, and results of calculation, are presented by numbers or graphically for the offered example.

## Delimitation of application of stationary and non-stationary models of the gas pipeline operation

The author of the work offers the way of delimitation of preferable application of a stationary model, and the model which describes non-stationary process of the gas pipeline operation. Scientifically reasonable choice of a settlement model is the key question for the gas pipelines calculation. The importance of such differentiation in practice is that it makes sense to use simpler stationary model if variability of parameters is not big and doesn’t entail inadmissible errors. The author of the work shows this way on concrete models: standard calculation of a stationary operating mode of the gas pipeline, offered, for example, in norms of design and the calculation of the well-known system of the equations which describes non-stationary process by “the way with variable coefficients”. This way of calculation was significantly modified by the author for the accounting of the heat exchange, and also, for gravity influence. The specified adjustment is described in detail in the other publication of the author. In the offered way of differentiation of scopes of stationary and non-stationary models of the gas pipeline hydraulic calculation, the comparison of results of calculation of both models according to the same regime data is used. Results of calculation of both models have to be compared in sizes of the calculated losses of energy of gas compression in the gas pipeline. The choice, for example, of this parameter is caused by that in the solution of the specific objective concerning the gas transport, the size of losses of energy of gas compression in the gas pipeline defines the main part of expenses of energy carriers at the compressor station. Therefore it is the key indicator in an assessment of an operating mode of the gas transmission system and in the choice of the most economically expedient option of an operating mode. The essence of definition of the required border consists in that the distinctions of results of calculation for both methods which are exposed to differentiation, are comparable to errors of these methods. The application of the offered way is shown on calculation of the concrete example. For all counted parameters, settlement ratios are offered, and results of calculation, for the reviewed example, presented by numbers or graphically.