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UGS SYSTEM OF OAO “GAZPROM” - AN IMPORTANT PLAYER OF GAS SUPPLY FOR RUSSIA AND FOREIGN COUNTRIES AND NEW TECHNOLOGIES IMPLEMENTED.
SYST~ME DE STOCKAGE SOUTERRAIN D’OAO {( GAZPROM )) - UN ELEMENT IMPORTANT DANS L’APpROvlslONNEMENT EN GAZ POUR LA RUSSIE ET LES PAYS ETRANGERS UTILISATION DE NOUVELLES TECHNOLOGIES
V. Remizov, V. Parfenov, A.Arutunov, S. Khan, S. Buzinov, V. Smirnov, V. Kazaryan OAO GAZPROM, Russian Federation
ABSTRACT
In territory of Russia, Ukraine, Latvia, Germany OAO ‘GAZPROM stores the working volumes of gas, which size comes nearer to 100 *109 cubic meters, that alongside with production of gas and uninterrupted work of gas transmission system of OAO ‘GAZPROM has allowed to ensure reliable gas supply to the consumers of Russia, “near” and “far” foreign countries. In connection with transition to the market relations a peak gas demand has increased. The essential increase of daily productivity of OAO ‘GAZPROM” UGS on territory of Russian Federation is planned for the coming years. The escalating daily productivity of UGS are carried out on upgrading of existed UGS and new UGS construction. The technologies implemented on upgrading of existed UGS and new UGS construction are discussed in this paper.
RESUME
OAO <(GAZPROM )>stocke Ies volumes de gaz necessaires sur Ies territoires de Russie, d’Ukraine, de Lettonie et d’Allemagne. C’est ce volume - pres de 100.109 m3– associe a la production de gaz et a un systeme de transport fonctionnant saris interruption, qui permet a OAO (
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1.INTRODUCTION
The russian science of underground gas storage was born right after the end of World War 11, when in 1946 the first long-length gas pipeline from Saratov to Moscow was commissioned. The first trial gas injection into a geological structure was made in 1958 and in 1959 first industrial gas injection into aquifer of Kaluga structure (near Moscow) was started. Since that time the Russian UGS system became a powetful sub-branch of Russian gas industry. In despite of it’s big capacity, the Russian UGS system is continuously being developed. Since the collapse of former USSR in 1991 for short time OAO “GAZPROM” had increased the working volume stored in Russian UGS up to value the working volume of the former USSR. A big plans for the further UGS system development in Russia was approved. Further UGS system development has to be supported by modern technologies and equipment.
2. UGS SYSTEM OF OAO “GAZPROM” - AN IMPORTANT PLAYER OF GAS SUPPLY.
In territory of Russia, Ukraine, LaNia, Germany OAO “GAZPROM” stores the working volumes of gas, which size comes nearer to 100 *109 cubic meters. The maximum productivity of GAZPROM’S UGS system at the beginning of a winter season 1999-2000 was 650*1 Oecubic meters per day, that alongside with production of gas and uninterrupted work of gas transmission system of OAO ‘GAZPROM” hasallowed to ensure reliable gas supply to the consumers of Russia, “near” and “far” foreign countries.
The UGS system of OAO “GAZPROM” performs the following functions: - meeting demand of seasonal swing gas consumption of Russian Federation and neighboring countries (Ukraine, Belorussia, Lithuania, Estonia, Georgia, Armenia) - additional gas deliveries in abnormal - cold periods - insurance of unregular situations in gas transmission system - maintenance of gas export reliability and seasonal swing of export deliveries - long - term gas reservation
OAO ‘GAZPROM” carries out gas export deliveries at distance more than 4000 kilometres, that can not be compared to conditions of deliveries to Europe from other sources. Despite of it, the advanced system of a gas storage of OAO “GAZPROM” integrated in Unified Gas Supply System(UGSS) of Russia and in system of export gas flows abroad allows: - to supply up to 15 ‘%. of annual gas consumption for Russian customers - to supply up to 22 % of annual consumption of Ukraine from Ukrainian UGS, that provides reliability of gas transit through Ukraine to the countries of Central and Western Europe - a covering of seasonal swing gas consumption of the next countries - Ukraine, Byelorussia, Lithuania, Estonia, Georgia, Armenia on 90-100 %% of these countries demand. - to supply up to 23 ?4. from daily consumption of Russia and gas export to the countries of “near” and “fat’ foreign countries. - reliable delivery of gas export and, moreover, seasonal swing of export to the countries of Central and Western Europe up to 5-7 YO from export volume - delivery up to 50 Y. of export volumes during a half of year from long-term reserves.
It is obvious, that in connection with increase of the Russian gas export, the volumes and geography of a gas storage of OAO “GAZPROM” abroad also will extend,
There are various forms on organisation of a gas storage outside Russian Federation: - in the form of joint venture - OAO “GAZPROM’ has shares in such enterprises in territory of Germany, Latvia and Armenia - the gas storage under commercial contracts - OAO “GAZPROM” stores gas in Ukraine, there were short-term contracts with another countries - combined - when both forms are combined. Such approach is realised in Germany and Latvia. . ,, .
3. UGS TECHNOLOGIES IMPLEMENTED IN OAO “GAZPROM”.
3.1. Development plans of UGS system of OAO “GAZPROM”.
Now all functions of Russian UGS system are completely realised. However, in connection with transition to the market relations, the change of fuel consumption structure a peak gas demand has increased. The essential increase of daily productivity of OAO “GAZPROM” UGS on territory of Russian Federation is planned for the coming years. By winter 2005-2006 the system Russian UGS will allow to supply in peak-periods up to 700’1 OGper day, that for 7 years periods means practical doubling of daily production capacities.
The tasks on escalating daily productivity UGS are carried out on the following directions: - modernisation, technical re-equipment and reconstruction of existed UGS facilities, that are accompanied by expansion of storage working capacity and increase of its productivity - construction of new UGS. Six new UGS is now under construction: one peak-shaving in the depleted gas field, two high productive UGS in salt caverns, two high productive UGS in aquifer and one UGS in a depleted oil field. In the perspective plans the construction of several UGS in aquifers and depleted gas fields is planned.
Distribution of investment in upgrading of existed facilities and new construction for the period 2000-2005 is distributed as follows:
1 Upgrading of existed UGS facilities, 75 % including: 1.1 technical re-equipment 10% 1.2 automation of existed UGS facilities 13 % 1.3 reconstruction, modernisation and expansion 52 % 2 New UGS construction 25 % 3 Total 100 y,
3,2. Upgrading of existed Russian UGS facilities.
The part of Russian UGS is under operation already rather long time. Therefore alongside with operation of existed UGS facilities their’s reconstruction, equipment modernisation and technical re-equipment is being made. One of the important task is also to increase the ecological reliability of the existed UGS.
The possibilities of working capacity and productivity increase of existed UGS, and also on increase of reliability of their operation are explored first of all in reservoirs part of UGS. For reliable monitoring of a gas bubble behaviour in reservoir the complex of geophysical, gas-dynamic and geochemical methods of wells and reservoirs tests is carried out, the 3D geological models are used, The gas bubble behaviour in reservoir is investigated with application of modern numerical simulators. In cases, favorable for it, on the basis of the carried out researches is raise maximum reservoir pressure, that allows simultaneously to increase working capacity of UGS and potential of daily productivity. The simulation can allow to determinate the best type and location of additional wells, optimum operational mode of reservoir, etc. for improvement of reservoir drainage.
For UGS daily productivity increase the large works are conducted with operational wells. A complex of works are made for the inspection of operational well casing. Good recommendation earned by methods and devices of magnetic-pulse inspection of wells developed OAO “GAZPROM, which allows to cany out operational well inspection without well-kill service.
In low productive wells the second hole (including horizontal) branching, casing cutting at bottomhole and also installation of new types of bottomhole screens usually are carried out. The . i=
filters with gravel pack in extended bottomhole formation zone and also two-layer gravel-pack filters developed by OAOGAZPROM” and requires minimum of works at H installation, allows extremely increase well productivity. In some wells maintained in unstable formations the use of chemical substances allows to create artificial bottomhole formation zone. The replacement of tubing of low diameter on the greater diameter is made for reduction of pressure losses in tubing. All these measures allow to increase productivity of existed wells up to 200Y0.
At expansion of UGS the new types of wells are applied: with horizontal boreholes which length reach 200-400 m and also vertical wells with tubing of 168 mm. Use of new types of wells allows to receive well productivity in 2-4 times higher, than in wells drilled earlier. For best drainage of some parts of reservoir which could not be drainaged earlier due to surface reasons, the directed wells are applied.
The new methods of well testing based on processing of continuous data acquitted from well during usual operation allow to receive the reliable information about well productivity with reduction of gas release into an atmosphere.
The change of the gathering system on some UGS from collective connecting pipe to individual one for each well allows to increase productivity of UGS on 20-30’XO.The change of the technology of gas dehydratation, modernisation of absorber units allows to process the bigger gas flows on the already installed equipment. The operational expenses is also decreased on 10-15%.
The importance has also modernisation and re-equipment of compressor stations of underground storages of gas. Replacement of morally and physically out-of-date piston compressors on modern types @s-turbine compressors with use a gas ejecting during separate periods of gas injections allow to decrease the operational expenses (up to 10YO)and emissions of CO and NOX into atmosphere.
On peak-shaving UGS the technology of gas injection during winter time will be use. This technology will allow to have in storage a gas volume allowing to ensure peak gas withdrawal at any period.
The importance in increasing of daily productivity has the use of automatic control systems. On UGS of OAO “GAZPROM domestic info-managing systems (lMS) are widely used. This IMS was developed by OAO “GAZPROM” in cooperation with Russian Space-Missile Enterprise “Energy”. The automatic management of technological processes at UGS facilities allows to reach increase of working gas volume and productivity of UGS up to 10 Yo.
3.3. Construtilon of new Russian UGS.
Alongside with upgrading of existed and operated UGS, accompanying by increase of working capacity and daily productivity, OAO “GAZPROM” commissions new underground storages of gas. So, in 1998 first was begun gas injection in aquifer of UGS Uvyaz, the first gas withdrawal from it was already in winter 1999-2000. In 1999 was carried out the trial gas injection into aquifer structure of UGS Bednodemyanovskoye; in 2000 will be commissioned the first one of UGS, included in an Udmurt Reserve Complex.
At a stage of creation are 2 UGS in salt caverns: Volgograd and Kaliningrad, at a stage of designing and in the perspective plans are 3 UGS in various parts of the country. All new UGS are designed with big working volume up to I* I 09 cubic meters and big geometrical volume of one reservoir reached 400-500 *103 cubic meters. New technologies was developed for cavern creation with big volume in thin salt bed. All these projects include the utilisation of brine on salt-producing or chemical plants. Such type of the project “UGS and salt plant” is very efficient.
At Volgograd UGS it is planed to create first trial-industrial reservoir of a tunnel type using two wells. The patilcularity of technology of cavern leaching is an existence of layers with low volubilityin depth of designed reservoirs. At Kaliningrad UGS it is planed to use the technology of join leaching and operation the same cavern. This technology allows to decrease construction period.
The creation of peak-shaving Talovskoye UGS in depleted gas field is planned, the withdrawal of working volume of 1*109 cubic meters will be done within 40-60 day.
The combination of processes of a gas storage and increase of oil recovery of the depleted oil field on projected UGS Terekla will allow to increase the final oil recovety till 25 up to 40Y0.
During exploration works on perspective for UGS creation structures an optimum combination of seismic serveys (including 3D seismic survey), shallow and deep exploration drilling, geophysical (logging), hydrodynamic (one well and multi-wells) tests of wells and reservoir, geochemical (including isotope methods), trial air or gas injection allow in the shortest time qualitatively prepare geological structures for designing and creation of UGS.
At designing and monitoring of UGS creation the newest methods of numerical simulations (including 3D multi-phase simulation) and also simulation of a hole chain “reservoir - well - connecting network - gathering centers - dehydratation unit - gas pipeline” are used. The use of last mentioned simulator allows to save pressure in UGS facilities and to achieve the best productivity of projected UGS. On new UGS the new types of wells are widely used: with horizontal boreholes in length 200- 400 i, increased diameter of the tubing up to 168 mm, directed wells, cluster pattern of well heads, and also is applied modern technology of well competition, new types of wells screens etc. Wellhead equipment is produced at factories of OAO “GAZPROM” and meets the international standards.
For new UGS equipment OAO “GAZPROM” approved the program on creation of new types compressors on the basis of turbines of Rybinsk and Perm air jet factories with power of 4,10 and 16 *106 wt.
New UGS equipped by info-managing systems (lMS) made by russian or foreign companies.
4. CONCLUSION.
The system of a storage of gas OAO “GAZPROM” - includes underground storehouses in Russia, storage of gas in other countries. On volumes and geography of a storage of gas, and also rates of development she(it) is largest and dynamical in the world belonging one company. Modern technologies, the level of used engineering allows UGS OAO “GAZPROM” confidently to step into the XXl century.