Eurotek-Yugra, a joint venture of Gazprom Neft and Repsol, has drilled a multilateral well with a total length of over 9.4 km at the Ervier field in the Khanty-Mansi Autonomous Okrug-Yugra. The initial flow rate exceeded 120 tonnes of oil per day — six times higher than the productivity of previously built wells in that area.
The new well has become one of the most complex drilling targets ever dealt with in Russia. Combining a number of unique technical characteristics the borehole’s directional difficulty index (DDI) stands at 6.69, compared to an industry average of 6*, running at a depth of around 800 metres the borehole’s footage drilled through the oil-bearing strata reaches 7.7 kilometres. The choice of design, drilling technology and testing programme was predicated on the subsurface conditions of the field.** Implementation of the project and obtained commercial inflows confirmed the commercial development potential of the field, initial reserves in place of which stand at about 200 million tonnes of oil.
Eurotec-Yugra has completed well testing by the second quarter of 2021. On the basis of the data obtained, a field development plan will be prepared. Engineering solutions with confirmed efficiency during this project will be replicated in the development of neighbouring deposits and other assets of the joint venture between Gazprom Neft and Repsol in the Karabashsky blocks.
“The new well confirmed the potential of developing Karabashsky license areas with total potential resources of 420 mtoe, allowing us to move on to the next phase of the project as well as to deploy the technology used here in developing other hard-to-recover reserves.”Vadim Yakovlev Deputy CEO for Exploration and Production, Gazprom Neft PJSC
Eurotek-Yugra is a joint venture (JV) between Gazprom Neft and Spain’s Repsol which was established in 2017. The company is managed by shareholders on a parity basis. The JV holds seven exploration and production licences in Khanty-Mansi Autonomous Okrug-Yugra (KhMAO). The company is conducting geological prospecting works within Karabashsky license areas located in the Kondinsky District of the Khanty-Mansi Autonomous Okrug.
The base field of the asset is the Raul-Yuri Ervier field (formerly the Ouryinskoye field), which was discovered at the Karabashsky 1 and 2 licence areas in 2013. Extensive testing of horizontal exploration wells was undertaken in 2016 and
* The DDI (Directional Difficulty Index) was 6.69, compared with the industry average of around six. The design is also characterized by a significant horizontal deviation from the surface drilling location: the ERD (Extended Reach Drilling) ratio of wellbore’s horizontal reach to its true vertical depth is 2.85, while for most wells it is less than 2.5.
The ERD classification allows to assess the complexity of horizontal well construction. It includes generalised global data on existing horizontal wells by distance from the surface drilling location.
The length of the main wellbore exceeded 2.2 km, with four additional wellbores ranging in length from 1,350 to 1,650 m.
The Raul-Yuri Ervier field is characterised by a heterogeneous, thin-layered reservoir, the abundance of faults and uncertain saturation, water-oil and gas-oil contact patterns. Construction of the well was preceded by the construction of a geomechanical model of the reservoir and modelling drilling processes in heterogeneous formations, confirming the need for non-standard approaches to the reservoir development.