Building up resource base
Published in corporate Gazprom Magazine Issue 3
Gazprom’s Geological Exploration Program will not be considerably adjusted
Despite a not too favorable international economic situation, sector-specific sanctions of the USA and Europe against Russia as well as a difficult financial environment in our country, Gazprom keeps enhancing its mineral resource base as well as getting ready for development operations at new discoveries. The Company identified Eastern Siberia and the Far East as the key exploration targets. Intensive exploration activities will continue in the Yamal Peninsula, Nadym-Pur-Taz region, in northern seas of Russia as well as in the CIS, Asia, Africa and South America.
In 2014 Gazprom Group (excluding Gazprom Neft) performed exploratory drilling of above 125,000 m of rocks, constructed 32 prospecting and exploratory (7 and 25 accordingly) wells. Over six thousand linear kilometers of 2D seismic profiles were processed, 3D seismic survey covered in excess of 11 thousand square kilometers.
In the Russian Federation, prospecting drilling was performed across an area of more than 112 thousand meters of rocks. 30 prospecting and exploratory (24 exploratory and 6 prospecting) wells were constructed. Above six thousand linear kilometers of 2D seismic profiles were processed, 3D seismic survey covered the area of above 11 thousand square kilometers. In 2014 Gazprom Group added 936 million tons of fuel equivalent to explored hydrocarbon reserves through geological exploration, with 816 billion cubic meters of gas, 114 million tons of condensate and 6 million tons of oil. The gas replenishment coefficient made up 1.83. The additions were mostly due to exploration activities in the Yamal-Nenets Autonomous Area, offshore Sakhalin and in the Astrakhan gas and condensate field. The bulk of added reserves are located within the existing fields, which raises their economic significance.
The exploration activities in Russia resulted in the discovery of the Vostochno-Imbinskoye gas field in the Krasnoyarsk Territory. The field C1+C2 reserves make up 14 billion cubic meters. Moreover, nine new hydrocarbon deposits were identified at the previously discovered fields in the Yamal-Nenets Autonomous Area, Tomsk Region and Krasnodar Territory containing a total of 55 million tons of fuel equivalent in commercial categories. The biggest deposit was identified in the Jurassic sediments of the Pestsovoye field in the Yamal-Nenets Autonomous Area. It contains 45 million tons of fuel equivalent (C1+C2), including 21 billion cubic meters of explored (C1) gas reserves.
Gazprom International, the Group’s operator of upstream projects abroad, drilled over 12 thousand meters of rocks in 2014. This helped to build an ultra-deep prospecting and appraisal well Shakhrinav-1p (6,450 meters) in Tajikistan. This is currently the deepest well in the entire oil and gas drilling history of Central Asia. The drilling operations made it possible to obtain unique information about the complex structure of the Shakhrinav area, thus enabling to optimize the project solutions as well as to outline more thoroughly the geological model and delineate further exploration targets. Besides, the drilling of exploratory well RSHN-1 (4,100 meters) resulted in a discovery of the North Rhourde Sayah field in Algeria.
Key projects and regions
In 2014 the main prospecting and exploration areas were the same: Yakutia, the Irkutsk Region, Sakhalin shelf, the Yamal Peninsula, the Nadym-Pur-Taz region, the Barents, Pechora and Kara Seas.
According to the plans set, last year prospecting and exploration drilling exceeded 16 thousand meters of rocks, nine exploratory wells were built, and 3D seismic survey covered some two thousand square kilometers at the Chayandinskoye oil and gas field in Yakutia. At the Kovyktinskoye gas and condensate field, Irkutsk Region, over 6 thousand meters of rocks were drilled and 3D seismic covered an area of around 1,000 square meters. In Western Siberia over 69 thousand meters of rocks were drilled, 10 prospecting and exploratory wells were constructed and three thousand square kilometers of 3D seismic was performed.
Geological exploration is underway in the Sea of Okhotsk, in the Kirinsky, Vostochno-Odoptinsky, Ayashsky and Zapadno-Kamchatsky blocks. In 2014 two exploratory wells were constructed at the Yuzhno-Kirinskoye gas and condensate field, with 6,040 meters of rocks drilled. The wells testing made it possible to confirm the gas presence in the Upper Daginsk deposits. 3D seismic survey was performed across an area of 1.2 thousand square meters at the Vostochno-Odoptinsky licensed block, currently they are being processed and interpreted. At the Ayashsky and Zapadno-Kamchatsky blocks, the focus on placed on summing up the obtained exploration data and updating the geological models.
On the Kara Sea shelf, geological exploration is going on at the Semakovsky, Antipayutinsky and Tota-Yakhinsky licensed blocks. At the Kruzenshternsky block, the drilling of a directional well with a horizontal completion was initiated. Having a projected depth of 4.9 thousand meters, the well is meant to reach the Tanopchinskiye deposits (Barremian-Aptian).
Besides, last year preparations were initiated on the prospecting and estimation of all new offshore licensed blocks. By now, Gazprom holds licenses for 32 blocks on the Russian continental shelf: seven – in the Barents Sea, 20 – in the Kara Sea, including the Ob and Taz Bays, and five – in the Sea of Okhotsk. In 2013 Gazprom was granted 17 subsurface use licenses for the shelves of the Kara, Barents, Chukchi and East-Siberian Seas to perform exploration and production activities in line with the Russian Federation Government’s Directive. In 2014 the following operations were carried out at the licensed blocks of the Kara Sea: 2D seismic survey of above 5 thousand linear kilometers – at the Leningradsky, Rusanovsky, Zapadno-Sharapovsky, Severo-Kharasaveysky, Obruchevsky and Nevsky blocks, 3D seismic survey of above 3 thousand square kilometers – at the Nyarmeysky and Skuratovsky blocks.
Gazprom is also active in developing tight reservoirs and fields with a complex geological structure located, in particular, in the Kuznetsk Coal Basin and the Nadym-Pur-Taz region of the Yamal-Nenets Autonomous Area. For instance, Gazprom continues the innovative project for coalbed methane production from Kuzbass coal fields according to the Russian President’s assignment. In 2014 methane reserves were calculated in the coal seams of the Naryksko-Ostashkinskoye coalbed methane field (Naryksko-Ostashkinskaya area), 26 exploratory wells of which being in test production. This year four exploratory wells with a total depth of above 2 thousand linear meters will be drilled as part of prospecting and estimation activities at the Tutuyasskaya area.
The development of hard-to-recover hydrocarbon reserves from the Turonian deposits of the Yuzhno-Russkoye and the Cenomanian deposits of the Medvezhye fields is in progress in the Nadym-Pur-Taz region. The Jurassic deposits are being currently explored. Namely, in 2014 a predictive model of reservoir properties was developed in the course of exploring hard-to-reach hydrocarbons in the Turonian deposits of the Yuzhno-Russkoye field. This model is based on applying inversion methods to high-density and high-resolution 3D shooting. Two exploratory wells were constructed, with depth exploration carried out through comprehensive well logging techniques. Isolated core sampling was performed in three exploratory wells.
Prospecting and estimation operations are going on within the Medvezhy licensed block to survey the tight hydrocarbon reserves of the Senonian deposits. In 2014 3D seismic was continued there using the adaptive vibroseismic prospecting (AVSP) method developed in Russia. In addition, prospecting and exploratory wells from the old well stock were reactivated to study the Senonian deposits using well stimulation methods.
New technology introduction
Gazprom continues gradually adopting domestic technologies in the geological exploration process. Thus, starting from 2013, the Yenisei electromagnetic pulse sources of seismic waves have been used in 3D seismic survey at the Kovyktinskoye gas and condensate field. The devices are produced by Geotech – a Russian design & engineering company. Having a low impact on the environment, these sources can be used in the areas where the use of other seismic sources is impossible. Moreover, this year it’s planned to install at the field a home-produced hardware and software package of an adaptive control system dealing with accumulations upon excitation of electromagnetic waves by a pulse source also developed by Geotech. This complex allows for online detection of accumulations of seismic vibrations in non-explosive pulse excitation needed to achieve the intended signal-to-noise ratio. The development activities proved that the adaptive control system ensures better quality of seismic data and saves the time of field survey by 8–10 per cent.
The Senonian deposits at the Medvezhye field are studied using the Avis adaptive vibroseismic prospecting technology developed by Russian company Geophysical Data Systems. It is based on the use of nonlinear sweep signals adapted to seismic geological conditions at each source point while conducting on-site survey operations. Such a technology enhances the resolution of seismic record and improves the signal-to-noise ratio for desired target horizons.
Besides, Gazprom applies the Pangea software package in exploration activities. It was designed by Russian company Pangea to ensure comprehensive interpretation of geological and geophysical data. It allows solving geological issues using a full set of geological and geophysical data available for a studied area. Moreover, Gazprom Georesurs, a subsidiary company of Gazprom, widely applies the Rusich vibroseismic sources developed by Geoswip while conducting seismic operations.
It is planned to perform comprehensive treatment and follow-up interpretation of 2D/3D seismic data as well as to build a single geological model of the Abakansky and Imbinsky licensed blocks in the Krasnoyarsk Territory on the basis of domestic software.
Problems and solutions
Among the factors that, to a certain extent, hinder the prospecting and exploration activities are the administrative obstacles. This applies to, for instance, extended terms of state review of project documents, registration of documents of entitlement for the use of land plots and forest areas to perform exploration, making revisions and additions to subsurface use licenses, expanding the list of subsurface users of shelf blocks. These problems are met with sympathy by the federal executive authorities. Thus, the Interdepartmental Commission on Removing Administrative Obstacles in the Subsurface Use Area was set up under the Russian Ministry of Natural Resources and Environment in 2014. Gazprom is actively involved in this activity. As a result, the construction of prospecting and exploratory wells was exempt from the Town Planning Code regulation, which considerably simplified the review and approval of construction documents and cut down the terms of prospecting and exploration activities.
It should be mentioned that state support is needed today for offshore operations in respect of comprehensive and simultaneous construction of port infrastructure and icebreaker fleet, especially in the Arctic and Far Eastern regions, accelerated design of national standards regulating industrial and environmental safety within the hydrocarbons development process, production and transmission projects on the continental shelf, state support to shipbuilding and engineering companies in construction of marine equipment, offshore oil and gas structures and installations aimed, inter alia, at prioritized engagement of Russian producers in geological survey and industrial development of the mineral resources contained in the continental shelf
As for the sectoral sanctions imposed by the USA and the EU on Russia, they currently have no significant impact on the exploration unit of Gazprom Group. Thus, all major international petroleum servicing companies are involved in Gazprom’s projects abroad – none of them expressed the intent to break up the cooperation with Gazprom or somehow to change the contractual terms. There are no significant changes in relations with foreign partners – the joint work is going ahead, the projects are in progress. At the same time, there is certain dependence on supplies of foreign equipment and technologies from western countries, needed for the construction of wells on the Russian shelf and caused by a lack of domestic counterparts. Therefore, the sanctions may indirectly affect Gazprom’s business aimed at building up the resource base. However, it can be said with confidence that the planned scope of geological exploration will not change, though its timelines may be extended.
Plans and prospects
The long-term plans for prospecting and exploration in Gazprom Group’s blocks are primarily determined by the Gas Industry Mineral Resource Base Development Program until 2035 annually updated in line with the targets and objectives of the Company. The main exploration regions will remain the same, namely, Yakutia, the Irkutsk Region and the Krasnoyarsk Territory in addition to the Far East, where the fields offshore the Sakhalin Island will be developed. The Yamal Peninsula, the Nadym-Pur-Taz region and Russian northern seas will also be among the constant exploration targets over a long-term prospect.
In 2015 Gazprom Group is going to complete exploration and prospecting drilling covering more than 149 thousand meters and complete 48 exploratory and prospecting wells, perform over 18 thousand square kilometers of 3D seismic survey. The bulk of exploration will be concentrated in the Western and Eastern Siberia and in Russian seas.
Geological exploration is in progress beyond Russia – in the CIS, Asia, Africa and South America. Namely, this year Gazprom International is going to carry out prospecting and exploration drilling across an area of some 16 thousand meters of rocks and build four exploratory wells in Algeria. It is also planned to drill around four thousand meters and build one prospecting well offshore Vietnam. In addition, magnetotelluric studies will be undertaken in the Azero block in Bolivia.