Source: Bulgartransgas EAD - DVGW

Spotlight Bulgaria: Experiences in Network
Maintenance in Bulgaria
Dr. Georgi
Overgas
Nikolov
Inc.
VI INTERNATIONAL CABLE AND PIPELINE SYMPOSIUM
– 02 April 2009, Berlin
NEW CHALLENGES IN CABLE AND PIPELINE CONSTRUCTION

Pipelines and Cables - Basis of Modern Infrastructure
This is a high priority infrastructure because it ensures:
Vital living conditions;
Energy – heat, light;
Water supply to population;
Communications – information;
Sustainable development of community and the
world.
Environmental protection is
a prerequisite for the infrastructure development.

50%
40%
30%
20%
10%
0%
The State of Gas Pipeline Design and Construction
Depends on the Gas Market
Comparison of Bulgarian gas market with the EU average level
Share of municipalities with access to the
transmission network (%)
Bulgaria
EU 27
15
80
0 50 100
Share of natural gas and electricity in Final Energy Consumption of households in EU -27 and Bulgaria
Bulgaria ЕU
35%
Electricity
11%
2%
45%
Natural gas
Natural gas consumption per capita (m 3 )
Bulgaria
EU 27
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
450
949
0 500 1000 1500
Structure of natural gas consumption in EU-27 and Bulgaria
47%
50%
3%
22,10%
39,40%
38,50%
Bulgaria EU
Source: Bulgarian Natural Gas Association
Energy sector
Industry
Household and
services

EUR/kWh
Price of Energy Sources for Residential Sector
0,100
0,090
0,080
0,070
0,060
0,050
0,040
0,030
0,020
0,010
0,000
0,093
0,089
0,056 0,053
Prices on 05.03.2009, incl. VAT
0,022
Electricity – household, daily tariff Industrial gas oil
Pricing Natural is based gas on: – residential consumers
Black coal
Heat energy – average for district heating plants

orecasts for Natural Gas Consumption
The expansion of natural gas use is a priority objective in Bulgaria’s energy
strategy.
Consumption Bcm/y
5
4,5
4
3,5
3
2,5
2
1,5
1
0,5
0
Year
3,4 3,7 4,2 4,7
2008 2010 2015 2020

Natural Gas Transmission Pipelines in Bulgaria

Basic parameters of the gas transmission system:
National transportation system –
-
length -
1
- 3 compressor stations
- operation pressure –
a closed ring with branches;
700 km, diameter from 200 –
1 000 mm;
(Kardam, Valchi Dol, P. Cenovets) –
55 bar.
Тransit gas system to Turkey(13.71 bcm/y, Greece (2.85 bcm/y) and
Macedonia(0.12 bcm/y);
-
length -
945
km , diameter from 500 to 1220 mm
- 6 compressor stations (Kardam, Provadia, Lozenets, Straldzha,
Ihtiman, Petrich) – 214 MW;
- operation pressure –
55 bar.
One underground gas storage Chiren:
- maximum daily production - 4.3 mcm /d;
- maximum daily injection – 4.0 mcm /d;
- active volume - 450 mcm ;
Source: Bulgartransgaz
49 MW;

Towns with Gas Distribution Network in Place
Gas distribution networks are built in:
Gas Distribution Companies Towns with Gas Distribution Network in Place
Sofiagas EAD (Subsidiary of Overgas Inc. AD) Sofia, Bozhuriste
Overgas Yug EAD (Subsidiary of Overgas Inc. AD) Asenovgrad, Pazardzhik, Parvomay
Overgas Zapad EAD (Subsidiary of Overgas Inc. AD) Kyustendil, Montana, Petrich, Mezdra
Dunavgas EAD (Subsidiary of Overgas Inc. AD) Ruse, Veliko Tarnovo, Razgrad, Gorna
Overgas
Total length of gas distribution networks ~ 3 000 km, of which
Steel gas pipelines ~ 500 km;
PEHD – gas pipelines ~ 2 500 km
Oryahovitsa, Lovech, Levski and etc.
Iztok EAD (Subsidiary of Overgas Inc. AD) Burgas, Varna, Stara Zagora, Yambol, Nova Zagora, Novi Pazar
Citigas AD Plovdiv, Karlovo, Haskovo
Black Sea Technology Company AD Dobrich, Pleven, Targovishte
TASSY OOD Kneja, Dolni Dabnik
Kavarnagas AD Kavarna
Sevlievogas AD Sevlievo
Balkangas AD Botevgrad, Pravets, Trudovets
Komekes AD Samokov, Borovets
Rilagas AD Blagoevgrad, Dupnitsa
Kamenogas AD Kameno
and etc.

Gas Distribution Networks
Basic (parameters) characteristics:
Configuration –
closed ring networks with branches from them;
Structure – distribution gas pipelines, gas regulating installations, gas
measuring installations, odorizing installations, gas line valves, cathode
stations and etc;
Twoor three-stage pressure regulation
- up to 0.01 MPa
- 0.01 – 0.2 MPa
- 0.2 - 0.5 MPa
- 0.5 - 1.6 MPa
Technological Scheme of Gas Distribution Network
1- Main branch pipeline; 2- Distribution gas pipelines; 3- Automatic Gas Regulating and Measuring Station; 4- Linear valve for
underground assembly; 5- Linear valve; 6- Condense collector; 7- Return valve; 8- Gas Regulating Station- 1C (City); 9- Gas
Regulating and Measuring Station; 10- Gas Regulating Station – 1I (Industrial); 11- Gas measuring Station; 12- Gas Regulating and
Measuring Installation; 13- Gas Regulating Installation; 14- Odorizing Installation; 15- Electro-chemical protection of steel gas
pipelines; 16- User Gas Pipeline branch

Gas Distribution Network Scheme of Sofia

Requirements to the Gas Pipeline Networks
The gas networks and related facilities secure the transportation of gas to the various
consumers in the built-up area. In accordance with the indicators for gas supply
quality the networks are to meet the following basic requirements:
high reliability and continuity of gas supply to the consumers according to
their category;
safe and efficient operation;
precise measuring of the gas flow and gas quantities sold to the consumers
controlled gas quality, and odorizing, securing safety of use;
optimal configuration and degree of pressure regulation;
optimal overhaul and operational costs;
environmental protection;
optimal matching to the infrastructure of built-up areas;
ensured protection against third party interference;
monitoring and control of network parameters through automated
information management system including identification of pre-emergency
and emergency modes.

Let us benefit from the experience of the leaders
and avoid their mistakes
Maintenance of pipeline networks in Bulgaria – one of the new EU membercountries,
is based on:
Efficient use of experience of EU and other countries;
Harmonization of Bulgarian technical standards with European
norms;
Avoidance of others’ mistakes;
Implementation of new technologies and equipment;
Application of state-of-the-art information technologies
(PIMS – Pipeline Integrity Management System) and others;
Setting of state-of-the-art management models (Business Excellence).

Avoidance of others’ mistakes:

Maintenance of Gas Networks
Reliability of gas supply is the property of the gas supply system to deliver the
required natural gas volume to the consumers uninterrupted, under the contract terms,
in compliance with pre-set working parameters and within a certain time frame.
The gas supply reliability rate is:
determined in the concept project;
underlying the working projects, the procurement of materials and
equipment, the implementation and control of construction works and
commissioning;
maintained in the course of the system operation and restoration during
implementation of restoration-repair works.
Bulgartransgaz EAD and Overgas Inc. subsidiaries use SCADA system.
SCADA serves to monitor the network pressure and flows, the natural gas
composition and specific burning heat, the condition of the stop and control valves,
the parameters of the devices. The data transfer is made through optic cable lines,
telephone lines, satellite and radio connectivity. SCADA uses logic modeling
programs, electronic equipment and standardization of computing networks.

Maintenance of Gas Networks
Operation of the gas network is run in compliance with the gas companies’ procedures
and instructions which are part of the Quality Management System under BSS
(Bulgarian State Standard) ISO 9000-2008, BSS EN 12007-1,4 and other standards of
TC-234-Gas Supply - CEN. Practices based on the DVGW documents and experience
are also applied.
The gas companies generate, maintain and store the operation documentation in the
format and volume in compliance with the statutory requirements during the complete
operational period of the energy sites. Part of the documentation is stored electronically.
The documentation contains the following minimum volume of:
acts of approval and commissioning;
executive documentation of the gas pipelines and facilities;
underground cadastre in the area of the gas pipe line;
technical passports of the gas pipelines valves and facilities (files
including description of the check-ups and repairs made);
operational log of the dispatch center;
action plan in case of emergency and
emergency-restoration works;
procedure of leak detection.

Maintenance of Gas Networks
The diagnostics is carried out through technical examination, tracking their route,
pressure measuring, mode modelling (computer monitoring), gas balance control,
in-pipe diagnostics with intelligent monitoring pigs (next slide).
Tracking the gas pipe line route
main pipelines with pressure ≤5,5 MPa
–
once in 2 months;
gas pipe line with pressure ≥0.4 MPa – twice a month at least;
gas pipe line with pressure ≤0.1 MPa and Main Branch Pipeline from an Automatic
Gas Regulation and Measuring Station outside a built-up area– once a month at
least.
Tracking the route of the distribution networks involves the following activities:
measuring of the safety potential of the cathode station for metal gas pipelines;
check-up of working pressure in Gas Regulation Station and Gas Regulation and
Measuring Installations;
reflecting any construction and assembly works under way in the proximity of the
gas pipelines;
check-up for the presence of natural gas in the shafts of other utilities
(communication, sewage) etc.
the minimum time span of the technical examination for steel gas pipelines is once
in 4 years;

Intelligent Pipeline Monitoring Pig
Source: Bulgartransgaz

Maintenance of Gas Networks
The reliability, safety and efficiency of the gas networks are secured by a system for
their technical maintenance and repairs. This system has two major aspects:
а) Maintenance and repair organization including:
maintenance structure (territorial location of the repairoperational facilities, number and qualification of the repair staff);
typization, sequence and matching of works;
logistics;
b) Current maintenance management including:
technical condition control, planning of schedule and volume of works;
organizational-technical management of staff and technical repair
equipment.
In the course of the system operation the necessary measures are undertaken to run
preventive maintenance on industrial consumers’ days-off or in certain consumers’
off-peak periods. In this manner the faulty element of the system can be switched off
without affecting the consumer. This aims to restore and maintain the pre-set
reliability level through a relevant analysis of the reliability of the individual system
elements and scheduled check-ups and repairs.

Maintenance of Gas Networks
The Preventive Maintenance(PM) System for gas distribution networks is
statutorily well regulated.
The statutory requirements are entirely based on:
the recommendations of the equipment manufacturers and the experience
from its operation;
the specific
qualification;
operational conditions and the actual staff
the actual technical state of the equipment and logistics;
their resource use rate;
technological systems and impact of reserve on reliability,
schedule and emergency stoppages,;
their repercussions and related repair costs;
the indicators of the pipeline system functioning as well.
off-

Maintenance of Gas Networks
Repairs of gas pipelines includes:
replacement of certain sections of gas pipelines;
restoration or re-enforcement of the gas pipeline walls with emergency
brackets;
Emergency (repair) brackets of Mat Ltd. for gas distribution pipelines
replacement of the surface gas pipeline supports;
replacement of gas pipeline terminals;
replacement of valve units;
displacement of gas pipelines.

Repair of Gas Pipeline with External Corrosion
Source: Bulgartransgaz

Lessons from the Crisis – January 2009
On 06.01.2009 natural gas supplies through Ukraine were stopped which resulted in:
introduction of a restrictive regime and daily consumption decrease from 12.5
mcm/d to 5.7-6.2 mcm/d;
gas supply only to residential users, public-administrative users (schools,
kindergartens, hospitals, etc.) and industrial users with continuous
production;
maximum daily production from UGS – Chiren – 4.3 mcm/d;
use of accumulated capacity of gas pipelines;
creation of technical conditions for receipt of 2.5 mcm/d through reverse
operation of the transit pipeline to Greece.
The experts from Bulgartransgaz, the subsidiaries of Overgas Inc., Citigas and others,
ensured an emergency-free operation of the gas supply system in the conditions of strict
restrictive regime.

Lessons from the Crisis
Lessons from the crisis caused by the suspended natural gas supplies through Ukraine.
It is necessary:
To speed up the introduction of the European regulatory framework into the
Bulgarian energy sector;
Designing and construction of closed gas pipeline networks
with an option for reversible running.
To implement the energy strategy projects:
- South Stream
- NABUCCO
- Construction of an LNG re-gasification terminal;
- Upgrading and expanding the Chiren UGS;
- Building new gas storage facilities (Galata and others);
- Building inter-system gas pipeline connections with
the networks of Greece (Komotini- Dimitrovgrad)
and Romania (Ruse-Gyurgevo).
Source: Bulgartransgas EAD

Cooperation for addressing problems
Ministry of Economy and
Energy
Ministry of
Environment
and Water
Ministry of Regional
Development and Public
Works
Non-Government
Organisations
State Energy and
Water Regulatory
Commission
State Agency of
Metrology and
Technical
Supervision
Regional and
Municipal
Governments
Ministry of Education and
Sciences
Bulgartransgaz
Licensed Gas
Distribution Companies
GAS Companies
Ministry of
Finance

Regulation vs. Liberalization
Regulation
Liberalization

Thank You for Your Attention!
Dr. Georgi Nikolov, Overgas Inc.
Tel.: +359 2 42 83 245
Mob.: +359 893 345 004
E-mail: georgi_nikolov@overgas.bg