The Messoyakha project
The Messoyakha group of fields is expected to become a crucial part of the country’s new oil province being developed in the north of the Yamalo-Nenets Autonomous Okrug. Commercial development of Russia’s northernmost onshore field — the Vostochno-Messoyakhskoye field — has already begun, forming part of the first stage in developing this project. The second stage is expected to involve opening up the reserves of the Zapadny (western) part of this group.
The first of the Messoyakha-group fields — the Zapadno- (Western-) Messoyakhskoye field — was discovered in 1983, and the second — the Vostochno-Messoyakhskoye — in the 1990s. These are the northernmost onshore fields currently under development in Russia. Complex underlying geology, however, together with the absence of any transport infrastructure, meant development at Messoyakha was delayed until the second decade of the 21st century.
Proactive pre-commissioning and development of this asset began following the decision to build the Zapolyarye-Purpe pipeline, connecting the northern fields of the Tyumen Oblast to the Eastern Siberia—Pacific Ocean (ESPO) oil pipeline transportation system. The license for exploration and development at Messoyakha is held by Messoyakhaneftegaz — a 50:50 joint enterprise between Gazprom Neft and Rosneft. Operational management of Messoyakhaneftegaz is the responsibility of Gazprom Neft.
Oil production at the Vostochno-Messoyakhskoye field — the starting point for development — is being undertaken exclusively through horizontal wells, involving horizontal sections of approximately 1,000 metres. This is necessitated by the geology of the deposits, further complicated by a significant gas cap. In addition to this, the oil-bearing rocks, located throughout various strata, are disconnected and of diverse origin.
To increase the coverage ratio of these more complex overlying strata «fishbone wells» — multilateral wells trunking from a main horizontal well — were used. Well-drilling technologies appropriate for such a diverse configuration were successfully tested and implemented in 2017, together with fracking operations in underlying production targets with abnormally high formation pressure — all of which has led to improved oil recovery..
A 98-kilometre pressure-pipeline, with a through-put capacity of 8.5 million tonnes per year, has been built to transport crude from the field to the Transneft pipeline system. This pipeline has been designed to take into account not just the severe climatic conditions of the region with winter air temperatures at the Gydan Peninsula often dropping below −50°С, but also the challenging local terrain and, moreover, the project’s impact on the local indigenous peoples and the environment.
The pipeline route avoids crossing feeding grounds for local deer pastures, and places sacred to indigenous peoples. Special crossings have been built on deer-herd migration routes, and where the pipeline traverses the major Indikyakha and Muduiyakha rivers crossed by migrating deer herds in winter and used by small-sized boats in summer it passes underground. These are the northernmost underwater crossings in Russia, built using directional drilling.
Cutting-edge technologies have been used in building the pipeline, in order to optimise its reliability — specifically, automatic and semi-automatic welding used by the company for the first time, and the pipeline equipped with leak-detection and anti-corrosion systems, on completion.
The high viscosity and lower reservoir temperature (about 8°С) of this oil notwithstanding, specialist oil production, processing and transportation technologies have not been necessary at Messoyakha — significantly improving the viability of the project.
However, in order to avoid thawing of the subsurface permafrost — which risks subsidence, landslides and, ultimately, serious accidents — all infrastructure has been built above ground. The construction of the core facilities alone — the central gathering point (CGP), the crude oil delivery and acceptance point (CODAP), and the gas turbine power plant (CTPP) — involved delivering about 50,000 tonnes of foundation piles (stilts) to the field, over temporary winter ice roads.
The further development of the Vostochno-Messoyakhskoye field envisages bringing the deep Achimovsky deposits (which lie at a depth of more than 3,000 metres) into production. Geological prospecting has made it possible to determine the extent of the deposit, and to confirm recoverable reserves of approximately 50 million tonnes of oil. Planned production from 2021 is expected to run at about two million mtoe per year.
The development of the western Zapadno-Messoyakshky license block, recoverable reserves at which stand at 129 million tonnes of oil and gas condensate and 74.2 cubic metres of gas, is a further area of focus in developing the Messoyakha project. Both projects share similar geological characteristics, which means that proven technologies used at the Vostochno block — specifically, horizontal and fishbone wells — can also be used at Zapadno-Messoyakha. Production is scheduled to start in 2021. Oil from Zapadno-Messoyakha will be transported to the integrated gathering station at the Vostochno-Messoyakhskoye field, from where it will feed into the Zapolyarye-Purpe trunk oil pipeline.