The article considers the technology absorption natural gas dehydration, systematization of the physical processes occurring in the technological chain of preparation of natural gas. Built fuzzy causal model of the process gas drying based on the combined application of fuzzy inference and neural network approximation. The use of the model enables the structural and parametric optimization of production, aimed at improving the quality of preparation of natural gas

A. N. Krasnov

M. A. Sharonov

V. E. Lyalin

English

Vibroengineering PROCEDIA

 182 © JVE INTERNATIONAL LTD. VIBROENGINEERING PROCEDIA. AUG 2016, VOL. 7. ISSN 2345-0533  
Methods of physical impact on natural gas in order to 
improve the safety of its transportation through main 
pipelines 
V. E. Lyalin1, A. N. Krasnov2, M. A. Sharonov3 
1, 3Kalashnikov Izhevsk State Technical University, Izhevsk, Russia 
2Ufa State Petroleum Technological University, Ufa, Russia 
1Corresponding author 
E-mail: 1velyalin@mail.ru, 2ufa-znanie@mail.ru 
(Received 4 August 2016; accepted 8 August 2016) 
Abstract. The article considers the technology absorption natural gas dehydration, 
systematization of the physical processes occurring in the technological chain of preparation of 
natural gas. Built fuzzy causal model of the process gas drying based on the combined application 
of fuzzy inference and neural network approximation. The use of the model enables the structural 
and parametric optimization of production, aimed at improving the quality of preparation of 
natural gas. 
Keywords: gas dehydration, absorber, gas transportation, air coolers. 
1. Introduction 
The water present in the gas in the vapor state, forms with methane, ethane and propane, the 
hydrocarbon hydrates, the settling in the pipeline in a solid phase [1]. To avoid the formation of 
hydrates, it is necessary to drain the gas. The moisture content in the gas is characterized dewpoint 
temperature value. Dew point is known as the temperature cools down to a moisture content at a 
constant gas reaches full saturation with water vapor and condensation of water vapor contained 
in the gas. Preparation of gas in field conditions is the removal of the condensate water [2]. 
Consider technology absorption dehydration of natural gas with the use of diethylene glycol 
as an absorbent in preparation for transport [3]. Gas from wells, is pre-cleaned in the centrifugal 
apparatus. After the booster compressor station (BCS) and the passage of air coolers of gas 
absorption process of drying is carried out. After passing the second stage compression BCS gas 
is transportation. The indicator is the moisture content of the dew point temperature (DPT). In 
accordance with OST 51.40-93 DPT value for temperate areas of: –3S summer, winter –5C. For 
cold areas, these values 10C and 20C, respectively. 
Natural gas treatment system can consist of several types of elements. First of all, this 
apparatus and process equipment. The system also includes maintenance personnel, production 
wells, external conditions, including weather. The aim of the system is to ensure that the desired 
properties of natural gas with minimum cost expenditures. Elements of the system are 
interconnected relationships, characterized by some of the variables and parameters. 
2. The model of the system 
Hardware exercising process, presented in the form of some converters that transform the 
values of input variables in the weekend. Let there be a central element ݌௜. Together with the 
elements ݌௝, ݆ = ݆ଵ, ݆௠, ݌௞, ݆ = ݇ଵ, ݇௅ an element ݌௜ forms a subsystem. Entrances to subsystem 
determines the relationship ܸሺ݆, ݅ሻ, ݆ = ݆ଵ, ݆௠, and outputs connections ܸሺ݅, ݇ሻ, ݇ = ݇ଵ, ݇௅. Nodal 
element ݌௜ carries out transformation of the form: 
܇ = Φ௜ሺ܆ሻ,    ܆ = ൣݔ௝൧,   ܇ = ሾݕ௞ሿ, ݆ = ݆ଵ, ݆௠, ݇ = ݇ଵ, ݇௅, (1)
where ܇ – output actions; ܆ – input actions. 
METHODS OF PHYSICAL IMPACT ON NATURAL GAS IN ORDER TO IMPROVE THE SAFETY OF ITS TRANSPORTATION THROUGH MAIN PIPELINES.  
V. E. LYALIN, A. N. KRASNOV, M. A. SHARONOV 
 © JVE INTERNATIONAL LTD. VIBROENGINEERING PROCEDIA. AUG 2016, VOL. 7. ISSN 2345-0533 183 
For example, the inlet separator provides a preliminary separation of the condensate from the 
gas [4]. Driving separator shown in Fig. 1. 
The crude gas is fed into the machine through the radial connector located on the fender gas 
inlet plate assembly for pre-separation of large liquid droplets and mechanical impurities. Due to 
the centrifugal effect created by the gas input node on the unit deposited liquid droplets and solid 
particles that drain into a collection of impurities through the annular gap between the housing 
and the protective sheet. After pre-cleaning gas is distributed evenly between the centrifugal 
elements in which it is separated from the liquid fine particles of the purified gas leaves the top of 
the elements and the liquid gets on the grid, so that by draining pipe drains into a collection of 
impurities. Grid centrifugal elements separates the raw gas from the purified. The liquid, which is 
in the collection of impurities is discharged from the machine to the drainage pipe [5, 6]. 
 
Fig. 1. Scheme inlet separator 
1000
 
Fig. 2. Shema absorber 
In this case, the input parameters are the thermodynamic (pressure, temperature, humidity) and 
thermal characteristics of the gas. For input parameters also include the technological 
characteristics of the process (the gas flow rate, gas twist, disperse composition of condensed 
moisture, the design features of the device, etc.). The output parameters include pressure, 
temperature, gas flow rate, moisture content. 
Conversion (1) may be a mathematical model of the process. The model can include equations 
of motion of multiphase medium in a multidimensional setting with phase transformations. 
Conversion may also appear as an engineering method of calculation of technical and economic 
parameters of the process. A more convenient system for the submission process is a mathematical 
model describing the neural network. Trained on a limited set of training samples containing 
experimental data network summarizes the accumulated information, and outputs the response to 
the data, is not used for teaching. 
For the drying gas used absorbers of various types (Fig. 2). The most widely used installation 
applying diethylene glycol (DEG). 
For the dehydration gas is used an aqueous solution of diethylene glycol. It absorbs moisture 
from the gas. Saturated water solution is easily recovered by evaporation of excess water. Gas 
enters the bottom of absorption column - a tower with a cap number of multiple plates. The lower 
part of the column is a scrubber, which serves to trap the condensed raw gas phase. Towards the 
rises in a column (in plates) gas down the aqueous solution of diethylene glycol, part of the column 
METHODS OF PHYSICAL IMPACT ON NATURAL GAS IN ORDER TO IMPROVE THE SAFETY OF ITS TRANSPORTATION THROUGH MAIN PIPELINES.  
V. E. LYALIN, A. N. KRASNOV, M. A. SHARONOV 
184 © JVE INTERNATIONAL LTD. VIBROENGINEERING PROCEDIA. AUG 2016, VOL. 7. ISSN 2345-0533  
above the top plate and coming out of the middle column. Before leaving it accumulates in the 
annular space below the bottom plate. In the area of the scrubber diethylene misses. Release glycol 
regulated automatic float level control. Liquid settles in the lower scrubber is discharged through 
the drain hole. At the top of the absorption column above the top tray is a second scrubber. It is 
designed to hold the absorbent liquid droplets entrained in the gas. After passing the upper 
scrubber dried gas leaves the column. 
For input variables discussed above, are added to the characteristics of the feed DEG. For 
output variables, in addition to the characteristics of dry gas, are added to the properties of 
saturated diethylene glycol carryover NDEG together with the gas. 
A solution of diethylene glycol, swallowed water from the gas goes to regeneration. First it 
passes through the heat exchanger, where it is warm towards diethylene glycol, released from the 
evaporator. The heat exchange apparatus of diethylene glycol containing water is heated and goes 
into the flash column in which the water evaporates from this diethylene glycol. 
Equipment installed on the gas treatment plants, operating under conditions of varying 
technological parameters of the prepared gas. Mining enterprises are faced with the problem of 
gas quality in the late stages of field development. Process gas treatment plant equipment must 
provide the required gas quality indicators in unstable conditions. In addition, you must take into 
account the increased requirements to the quality of the gas preparation and reliability of the 
equipment to ensure the basic indicators (providing the dew point, condensation reduction of 
losses, the absorbent hydrate inhibitors). Therefore, there is a constant improvement of the mass 
transfer devices through the use of various types of composite structures contact devices. For 
example, the applied centrifugal elements mounted on them and regular packing packets (Fig. 1). 
In this case, at high loads on the gas centrifugal separation contact-elements operate in a liquid 
dispersion mode (DEG) swirling gas flow to form a developed surface mass transfer. Nozzle 
surface due to a large free section, close to the cross section between poppet space, for a given 
operating mode, mainly, in the separation mode, as a process for mass transfer occurs between the 
nozzle and the gas flow with entrained liquid components. At low load operation of the combined 
gas contact step is characterized in that in this mode centrifugal contact – separation elements 
operate longer in a liquid dispersion operation, and the disruption of the film from the wall of the 
centrifugal nozzle and its runoff down. As a result, set in space between poppet regular nozzle 
plate works in irrigation mode (surface becomes mass transfer, with significantly greater than the 
mass transfer surface elements). This preserves the effectiveness of the process of gas dehydration. 
Application of section catching DEG (a dish with a filter – cartridges) allows the nozzle packages 
by reducing the gas flow rate to the gas velocity in the section of the apparatus to improve the 
quality of liquid separation, carried away by the mass transfer from the upper plate. The decrease 
in the removal of fluid filter – cartridges increases the turnaround time of their work and reduce 
losses from DEG with dry gas from the absorber. Application of the principles of uniform gas 
distribution over the cross section of the device allow the typical solutions to modernize absorbers 
of different designs. 
Thus, in the preparation of the block diagram of the process of preparation of natural gas as 
the elements of the system should add additional structural devices that alter the characteristics of 
the drying process. For example, an effective way to improve the temperature and pressure 
parameters of the process is the use of a two-stage drying technology at two temperature and 
pressure levels. In this case, the input separators upgraded regularly nozzle plate feed saturated 
DEG. As a result, significantly improve the working conditions of booster units of the first stage 
of compression. 
The introduction of additional structural elements on the one hand alter the characteristics of 
the gas, usually in the direction of improvement, but at the same time changes the costs of cost 
process typically upwards. Therefore, to be considered as variables of the system and cost 
characteristics. 
METHODS OF PHYSICAL IMPACT ON NATURAL GAS IN ORDER TO IMPROVE THE SAFETY OF ITS TRANSPORTATION THROUGH MAIN PIPELINES.  
V. E. LYALIN, A. N. KRASNOV, M. A. SHARONOV 
 © JVE INTERNATIONAL LTD. VIBROENGINEERING PROCEDIA. AUG 2016, VOL. 7. ISSN 2345-0533 185 
3. The fuzzy control model 
Consider the block diagram of the process of natural gas preparation process (Fig. 3). 
Structural elements of this system are: 
CGC – centrifugal gas cleaning; 
BCS + AC – booster compressor station + air coolers; 
A – absorber; S – stripper; ME – modernized equipment. 
The system has the properties described by the following input variables: 
ଵܺ – gas consumption; ܺଶ – input pressure; ܺଷ – gas temperature; ܺସ – moisture contents; ܺହ 
– the cost of upgrading the drying gas in the CGC; ܺ଺ – the cost of upgrading the drying gas in 
the absorber; ܺ଻ – the cost of an additional drying gas in the absorber; ଼ܺ – air temperature; ܺଽ – 
qualification of staff; ଵܺ଴ – upgrade costs recovery DEG. 
The output variables of the system are: 
ଵܻ – dew point temperature; ଶܻ – the cost of drying gas; ଷܻ – the total carryover DEG. 
Intermediate variables: 
ݑଵ – DEG; ݌- pressure; ܶ – gas temperature; ܹ – moisture contents. 
To consider the scheme of the process is assigned a fuzzy causal model, the structure of which 
is shown in Fig. 4. 
 
Fig. 3. Structure of technology system natural gas treatment process 
 
Fig. 4. The structure of the fuzzy model 
The relationship between these elements of the system are divided into two groups. The first 
group represents a transformation that alter properties of the gas being processed in the process 
equipment. This conversion is performed using a neural network of the form: 
܇ = ۴ሺ܅, ܆ሻ, 
METHODS OF PHYSICAL IMPACT ON NATURAL GAS IN ORDER TO IMPROVE THE SAFETY OF ITS TRANSPORTATION THROUGH MAIN PIPELINES.  
V. E. LYALIN, A. N. KRASNOV, M. A. SHARONOV 
186 © JVE INTERNATIONAL LTD. VIBROENGINEERING PROCEDIA. AUG 2016, VOL. 7. ISSN 2345-0533  
where ܅ – transformation matrix coefficients determined in the process of network training.  
The training set contains the results of tests and measurement devices obtained during the 
operation of the equipment. 
The first group relations include communication devices corresponding to the centrifugal gas 
purification, BCS + AC and absorbers. Inputs transformations are expendable and thermodynamic 
characteristics of the gas. Consumables-gas thermodynamic characteristics match and output 
variables. 
The second group of relations is based on expert opinions and methods of fuzzy inference. The 
basis for the operation of fuzzy inference is the kind of relations between the elements of the fuzzy 
system, containing rules, the names and functions of the terms of the terms belonging. 
Consider the way of defining relations of the second type on the example of relation ሺܺ଺ − ܣଵሻ. 
For the linguistic input variable ܺ଺  (the cost of upgrading the drying gas in the absorber) 
introduced three terms: ܮ – low; ܯ  – Average; ܪ  – The high costs of modernization. Output 
variables ݑଵ (diethylene entrainment) and ݑସ (moisture contents) are also three terms. For variable 
ݑଵ: ܮ – a slight decrease in ash; ܯ – Average reduction in ash; ܪ – A significant reduction in 
entrainment. For variable ݑସ : ܮ  – a small reduction in the moisture content; ܯ  – Average 
reduction in the moisture content; ܪ – Significant reduction in moisture content. 
Membership functions for the variable ܺ଺ shown in Fig. 5. 
Costs are measured by the value of a notional unit. Membership functions for the variable ݑଵ 
shown in Fig. 6. 
 
Fig. 5. Membership function for the costs  
for the modernization 
 
Fig. 6. Membership function for the measure 
reducing entrainment DEG 
There decrease ash DEG occurs in ݑଵ time. 
The relevant set of rules for the inference is as follows: 
if  ܺ଺ = ܮ  then  ݑଵ = ܮ, if ܺ଺ = ܯ then ݑଵ = ܯ,    if ܺ଺ = ܪ then ݑଵ = ܪ,
if  ܺ଺ = ܮ  then  ܹ = ܮ, if ܺ଺ = ܯ then ܹ = ܯ,   if ܺ଺ = ܪ then ܹ = ܪ.
The value of the variable corresponding to the element with the incoming communication is a 
weighted summation of all incoming calls: 
ݖ௝ = ෍ ݓ௜௝ݒ௜௝
௜
, 
where ݓ௜௝ – the weights that determine the contribution of the ݅th regard to the state of the ݆th 
element. The coefficients ݓ௜௝ shall be determined in the process of learning fuzzy network. 
When the structural optimization of small factors ݓ௜௝ → 0 lead to the rejection of connection or 
edges of the graph in Fig. 7. 
Training data are characteristics of the operational process  
ൣ൫ ௜ܺ௝, ݅ = 1,10൯, ൫ ௟ܻ௝൯, ݈ = 1,2,3൧, ݆ = 1, ℎ. Training is conducted by using a genetic algorithm. 
The calculated output value of the dew point temperature (DTP), depending on the gas flow 
METHODS OF PHYSICAL IMPACT ON NATURAL GAS IN ORDER TO IMPROVE THE SAFETY OF ITS TRANSPORTATION THROUGH MAIN PIPELINES.  
V. E. LYALIN, A. N. KRASNOV, M. A. SHARONOV 
 © JVE INTERNATIONAL LTD. VIBROENGINEERING PROCEDIA. AUG 2016, VOL. 7. ISSN 2345-0533 187 
rate at different levels of the cost of the modernization of the drying process shown in Fig. 7. 
The calculation for the winter period of time to change the amount applied to the preparation 
of natural gas. The value ܩ଴ corresponds to the optimal level boot process equipment ܩ = ଵܺ. Due 
to the additional funds allocated for modernization at the secondary level may be reduced to 
12 degrees while reducing gas consumption by 2 times. 
The model constructed of natural gas treatment system provides a response output variable ܇ 
to changes in the input variables ܆ of the form: 
܇ = Ψሺ܆, ܟሻ. (2)
With an appropriate choice of the system optimality criterion on the basis of the transformation 
Eq. (2) it is possible to put the problem of finding the optimal structure of the process flowsheet. 
 
Fig. 7. The dependence of the degree of DPT loading equipment and modernization costs 
4. Conclusions 
Ordering of the physical processes occurring in the technological chain of preparation of 
natural gas, it possible to establish the main factors affecting the drying options: high-speed mode 
of movement dispersed-annular flow in the mass transfer elements; temperature, pressure and 
humidity of the gas; concentration of the absorbent. 
A complex process modeling method using a causal network based on the combined use of 
fuzzy inference and neural network approximation. The method of teaching fuzzy network models 
using genetic algorithm with real-coded. 
Built on the basis of empirical data and expert, fuzzy simulation model of the process of natural 
gas treatment process allows for changing production conditions a rapid assessment of the natural gas 
indices prepared for transport. The use of the model enables the structural and parametric optimization 
of production, aimed at improving the quality of preparation of natural gas.  
References 
[1] Istomin V. A., Yakushev V. S. Gas Hydrates under Natural Conditions. Nedra, Moscow, 1992, p. 235, 
(in Russian). 
[2] Strizhov J. H., Khodanovich I. E. Gas Production. Institute of Computer Science, Moscow-Izhevsk, 
2003, p. 376, (in Russian). 
[3] Vyahirev R. I., Gritsenko A. I., Ter-Sarkisov R. M. Development and Exploitation of Gas Fields. 
Nedra, Moscow, 2002, p. 890, (in Russian). 
[4] Abasov M. T., Jalilov K. N. Questions Underground Hydrodynamics and Development of Oil and 
Gas Fields. Azerneftneshr, Baku, 1960, p. 255. (in Russian). 
[5] Cooper C. D. Air Pollution Control Methods. Kirk-Othmer Encyclopedia of Chemical. Technology. 
Wiley-Interscience, New York, 2007. 
[6] Laso M., von Stockar U. Absorption. Kirk-Othmer Encyclopedia of Chemical Technology. 
Wiley-Interscience, New York, 2007. 


Methods of physical impact on natural gas in order to improve the safety of its transportation through main pipelines

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Methods of physical impact on natural gas in order to improve the safety of its transportation through main pipelines

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