New high-strength “fishbone” well built at Gazprom Neft’s Vostochno-Messoyakhskoye field
Messoyakhaneftegaz has successfully completed construction of a new high-tech horizontal well at the Vostochno-Messoyakhskoye field — the Drilling Difficulty Index (DDI) of this well being among the highest in the industry.
The well is of “fishbone” construction,* with eight side-tracks. This technology means as many disparate areas as possible of the main productive strata at this Arctic field can be brought into production, increasing the oil recovery factor (ORF). Drilling took less than 25 days, with the depth of the wellbore running to more than three kilometres, and the total length of the well reaching 7.3 kilometres.
Constructing the “fishbone” well involved Messoyakhaneftegaz in a two-stage operation to lower the casing string into the open wellbore, protecting the structure from collapse, as well as potentially increasing its service life. The horizontal section of the well, together with the eight side-tracks, was undertaken without drilling equipment ever being switched off. The DDI in building this high-tech well was 6.9 — one of the highest in the oil industry.
Some few weeks prior to this Messoyakhaneftegaz had completed the construction of a similar fishbone well at the Vostochno-Messohyakhskoye field, with seven side-tracks. That 1.5-kilometre horizontal well was also reinforced with a casing string. Total drilling on this well was 5.3 kilometres, and the DDI 6.7.
Initial flow rate at each of these high-tech wells is expected to be in the order of 100 tonnes per day.
Victor Sorokin, CEO, Messoyakhaneftegaz, commented: “In developing the hard-to-recover reserves of the Vostochno-Messoyakhskoye field the company’s team is placing their bets on high-tech drilling. We continue increasing the number of side-tracks on horizontal ‘fishbone’ wells, select specific individual completion strategies for different strata and blocks, and implement technologies to extend the useful life of Messoyakha wells as far as possible. All of which is helping us produce oil — under the challenging conditions of the Arctic region — efficiently and profitably.”
The Messoyakha group of fields includes the Vostochno (Eastern) and Zapadno (Western) Messoyakhskoye blocks located in the Gydan Peninsula, in the Tazovsky district of the Yamalo-Nenets Autonomous Okrug. These fields are considered unique in terms of their proved reserves. The project is being implemented with very limited access to industrial and transportation infrastructure.
Licences to both blocks are held by Messoyakhaneftegaz, jointly owned by Rosneft and Gazprom Neft. President of the Russian Federation, Vladimir Putin, gave the instruction to commence commercial production at the field via video link on 21 September 2016. Total production at the field reached 10 million tonnes of oil in May 2019.
*Fishbone well design involves a multi-branched structure allowing the simultaneous drainage of reserves at various depths, significantly increasing coverage of oil-saturated areas.
, production technology