Achimov deposits extend over 12,000 square kilometers around the city of Novy Urengoy. These deposits are characterized by high reservoir pressures, and a narrow range of drilling fluid densities that creates complicated conditions for drilling and completion of wells. Due to the high accident rate of drilling horizontal wells only S-shape wells were drilled for this formation. The first successful horizontal production well was drilled in 2013 in cooperation Arcticgaz, ERIELL, Schlumberger. The first well to drill a horizontal wellbore on Achimov formation, has been planned to open Ach3,4 and Ach5 layers of Achimov formation. In close cooperation with project operator - Arcticgaz company, engineering group of Schlumberger drilling contractor and drilling contractor developed and successfully implemented comprehensive solutions for drilling and completion of horizontal wells Achim. One of the key factors of success was the use of drilling muds Megadril-D with constant control of equivalent circulating density. Application of rotary steareable system with optimally balanced PDC bits, allowed to drill horizontal wells through Achimov deposits in record time. An additional factor for drilling risks reduction was implementation of geomechanic model, as in the preparation of the preliminary model and real-time control for wellbore stability with the latest technology logging measurements (LWD) – acoustic and density neutron formation properties. In the period for 2013 to the 2nd quarter of 2014 have been successfully constructed more than 10 similar wells. Esteblished new records: maximum closure – 2403 meters, the length of the longest subhorizontal section reached 1233 meters. Set a record duration of well construction time of 62 days vs 100 planned, which could not been reached before by anyone in the region (formerly similar wells with shorter intervals of subhorizontal sectionhave been constructed in evarage about 150 days). Recently were successfully run two completion liners for 3-stage hydraulic fracturing (MSF) and one of MSF was successfully done. For completion purposes was used OBM with the weighting agent of mikro size, provided an unprecedented stability to settlement for a long time. This article devoted to the description of technologies and solutions that have been used for the construction of sub-horizontal wells. Preliminary production index of subhorizontal wells shows that current PI higher than S-shape wells (even with frac). Positive experience in the construction of subhorizontal wells change plans to develop Achimov deposits and opens new perspectives of hydrocarbon production in the region.

The interaction of NOVATEK, Investgeoservice (IGS) and Schlumberger allowed to deliver 2 complex extended reach wells (ERD), including the longest ever drilled in Russian mainland, well number 373, in the Yurkharovskoye field located in Arctic Yamal peninsula, as part of the offshore development plan from onshore locations. A geomechanical model was developed to address the main challenges, including optimum equivalent circulating density window and drilling regimes for wellbore quality and stability. Drilling & Measurements key technologies, multipole sonic-while-drilling, latest high-speed telemetry service, multifunction logging-while drilling technologies were used for real time Geomechanics service to prevent costly wellbore stability issues. In addition the combination of rotary steerable technology with customized polycrystalline diamond compact bits and drilling fluid system, delivered superior drilling performance, resulting in high performed drilling of these complex wells. Positive experience in the construction of these ERD wells, gives grounds to include options for developing the region, similar wells in the planning stage of various development scenarios. This article devoted to the description of technologies and solutions that have been used for the construction of these wells.

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