Western Siberia is the Rosneft’s key oil-producing region. In 2018, Western Siberian assets accounted for 59% of the Company’s liquid hydrocarbons production. The Company’s key producing assets in Western Siberia include RN-Yuganskneftegaz, which makes up 30% of the Company’s liquid hydrocarbons production, Samotlorneftegaz (8% of total Rosneft liquid hydrocarbons production) in the Khanty-Mansi Autonomous Area, and RN-Uvatneftegaz (5% of total Rosneft liquid hydrocarbons production) in the Tyumen Region’s south.
To increase the efficiency of reserves recovery at the Western Siberia fields, the Company has conducted comprehensive optimization of the existing development systems by shifting from traditional directional wells to multi-stage hydraulic fracturing horizontal wells (MSHF HW). This technology significantly boosts the wells flow rate and scope of reserves under development, while reducing the wells stock and enhancing the economic efficiency of the projects. MSHF HW is actively used at such enterprises of the Western Siberia as LLC RN-Yuganskneftegaz, LLC RN-Purneftegaz, JSC Samotlornefegaz, JSC RN-Nyaganneftegaz, and PJSC Varyoganneftegaz.
Western Siberia is also a major gas producing region. Gas output in 2018 totaled 47.45 bcm.
From 2004 to 2016, annual crude oil production in the fields of the Uvat project increased by almost 10 times (from 1.2 mmt to 11.6 mmt). The decrease in 2017–2018 was attributable to the production cuts under OPEC+ Agreement.
In September 2018, RN-Uvatneftegaz reached a milestone 90 mmt since the commencement of the Uvat project.
The highest growth of liquid hydrocarbons production in 2018 - above 80% - was recorded in the fields of the Central Uvat. The promising Taltsiyskoye field was commissioned in 2018. Today it produces over 2.8 thousand tonnes of oil per day.
In the reporting year, 78 new wells were launched at the Uvat project fields. Initial flow rates of new wells increased by 31% year-on-year and exceeded the level of 100 tonnes per day per well.
In 2018, RN-Uvatneftegaz reached the first million tonnes of oil at the South Gavrikovskoye field. Currently, 20 oil wells provide an average daily production of 1 thousand tonnes.
Despite the long history of the subsidiary, RN-Yuganskneftegaz has a stable positive trend of production: on 17 October 2018, RN-Yuganskneftegaz set a new absolute historical record of daily oil output of 197.5 thousand tonnes, which is the highest reading over the entire company’s history since 1964. Annual production increased by 5.5% year-on-year, and for the first time in the history of New Russia exceeded 70 mmt.
RN-Yuganskneftegaz attained these high production levels due to the improved development methods for hard-to-recover reserves of the Middle Priobye, application of advanced well drilling and completion technologies, systematic work on the expansion of resource base, the introduction of new production facilities, and contribution of the company’s personnel.
In 2018, with the commissioning of the Sorovsky field, production was started at the East-Salymsky license area. A synergy in relation to joint use of oil treatment infrastructure at the Sorovsky Central Production Facility (CPF) with further delivery of marketable products into the Transneft’s oil pipeline system was implemented within the scope of the project. 15 new wells were commissioned at the field with a total initial flow rate of above 10 thousand tonnes per day.
RN-Yuganskneftegaz continued to set record highs for the industry in terms of to drilling footage and new commissioned wells. Over 5 mln meters of rocks were drilled and over 1.6 thousand new wells were commissioned in 2018, 25% of which were horizontal. The pilot works on drilling the extended horizontal wells with an increased number of MSHF stages continued; over 50 horizontal two-string wells were built. In 13.4 days, a 4.7 km deep horizontal well was built with a unique combined production string with more than 1.5 km horizontal section.
As to the implementation of the decisions taken in relation to development systems optimization at the RN-Yuganskneftegaz fields, in 2018, a share of horizontal wells in production drilling increased from 14% to 25% year-on-year, while a share of MSHF HW increased from 12% to 22%. 368 new MSHF HW were commissioned, and their total amount, including horizontal sidetracks with MSHF, exceeded 500 wells per year.
To increase the output of wells and enlarge the scope of development coverage, over 30 wells with an extended horizontal section with eight and more HF stages were commissioned at RN-Yuganskneftegaz (more than 1.2 km). The average initial flow rate of these wells is 50% higher than at the wells with a standard length and a regular number of stages.
Total number of hydraulic fracturing operations was 5.5 thousand, including hydraulic fracturing of the well with 20-staged completion.
Intensified development of hard-to-recover reserves, which were previously considered unprofitable for drilling, has become the key area for RN-Yuganskneftegaz operations. The company conducts testing and introduces new technologies of MSHF HW completion, executes pilot works on horizontal well extension and increase of hydraulic fracturing stages. Additionally, different technical solutions are implemented to enhance the operational efficiency of the horizontal wells. New field development systems are introduced while old ones are optimized.
Commercial production at the Samotlorskoye field began in 1969 and peaked at over 150 mmt per year in the 1980s.
Due to the natural depletion of residual reserves and a high water cut (96%), today the field produces oil with a considerable amount of formation water. The main objective in maintaining the field’s production is implementing advanced technologies and starting the development of new untapped reserves.
Under Federal Law No. 335-FZ On Amendments to Parts One and Two of the Tax Code of the Russian Federation and Certain Legislative Acts of the Russian Federation dated 27 November 2017, annual MET reductions of RUB 35 bln over 10 years were approved for the Samotlorskoye field from 1 January 2018.
As a result of those investment incentives for the Samotlorskoye field and early revision of the development program, the Company managed to implement the production stabilization program, significantly reducing the decline in production to 1.1% in 2018 after several years of falling by 3–5%. In 2018, the number of new wells put into production increased by 122 wells year-on-year, while the number of well interventions increased by 197 wells. Additional oil and gas condensate production rose to 2.3 mmt due to well interventions, with 1.2 mmt of this growth due to drilling new wells.
The company continues pilot works on optimization of structures by means of an extended horizontal section and more stages of hydraulic fracturing, which increases the output of wells and enlarges the development coverage. Over 20 extended horizontal wells with eight and more HF stages were commissioned at JSC Samotlorneftegaz (more than 1.2 km). The average initial flow rate of these wells is 16% above the wells with a standard length and regular number of stages.