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.

As part of the field development plan Novatek, Russia's largest independent natural gas producer, recently planned an extended reach drilling (ERD) campaign at the Yurkharovskoye field, in the northern part of Western Siberia, Russia. The focus of this campaign is the development of an offshore part of the field from onshore locations using ERD techniques and implementation of new systematic approach -specific combinations of the drilling technologies, engineering and organizational solutions.Developed a new drilling program based on engineered drilling system (EDS) approach. Geomechanical model was created to address main challenges related to wellbore stability. Key drilling and measurement technologies, including multipole sonic-while-drilling, high-speed telemetry, multifunction logging-while-drilling technologies in combination with rotary steerable technology, polycrystalline diamond compact bits and oil-based drilling fluid were used to deliver superior drilling performance and control drilling regimes in real time. Another specific of this project was multilateral completion at TAML (Technology Advancement for Multi-Laterals) level 3 junction and the deepest casing exit from 178-mm string alone with the first in mainland Russia run of LWD tools for the direct formation pressure measurement while drilling.Four extended reach wells were drilled in this Yurkharovskoye ERD campaign with outstanding results in performance. Use of most advanced and superior technologies allowed setting several records for entire mainland Russia and to successfully drill and complete the longest ERD and longest multilateral ERD wells. A new approach in interaction between all participants in the project and engineered technological solutions as part of integrated drilling system was successfully implemented on all wells acknowledging its effectiveness in improving project performance and elimination of undesired incidents. Geomechanical model updated in real time was crucial in defining safe operational drilling parameters and regimes, together with precise drilling-fluid management, enabled rapid response to actual well conditions (i.e., fracture gradients, wellbore stability, hole cleaning and high torque) while drilling. Use of special casing milling system allowed performing whipstock orienting and casing exit in one run with full-size window at high inclination and long departure from surface. Well construction and production objectives were successfully archived and led to changes to the field development plan including planning new ERD wells for shallower pay zones on the field. This paper will describe how multidisciplinary well design and construction team addressed drilling challenges in variety of extended reach horizontal wells in Yurkharovskoye oilfield. Achieved results of new approach for complex technical projects will be presented; lessons learned and plans for future field development will be described.

Construction wells on the Achimov deposits was accompanied by many problems: the danger of sticking and oil, gas and water inflow; a serious decrease in the mechanical ROP on dense layers; severe downhole conditions: vibrations on dense interlayers, temperature up to 110°C, drilling mud based on diesel fuel. All of the above issues increased the number of trips due to equipment failures, increased non-productive time and, as a result, increased the well construction period. The integrated approach described in this work has significantly reduced non-productive and well construction time. The customer was suggested: –Limitation the mechanical rate of penetration (ROP) by 15m/h to control equivalent circulating density;–Control of the equivalent circulation density by the MWD sensor;–Combination of a modular motor with rotary steerable (RSS) system in bottom hole assembly (BHA) to increase the mechanical ROP during drilling in dense layers of the productive horizon;–Optimization of the bit design, taking into account geological features, meanwhile drilling with a rotary-steerable system;–Use of a new generation rotary- steerable system;–Optimization of the BHA;–Modernization of equipment preparation procedures. An integrated approach to drilling wells on the Achimov deposits with new methods and technologies offered to the customer allowed reducing the number of failures by 100-200%, which reduced the number of runs, and as a result, the non-productive time decreased. The reduction in the number of runs allowed taking from 500 − 600 meters to 1200 − 1500 meters per run. Optimization of the bottom hole assembly, including a new bit design in Russian Federation, integration of a new generation of rotary-steerable system with a modular motor, made possible to expand the boundaries of drilling modes, accordingly increase the mechanical rate of penetration. In addition, the adopted methods and technologies allowed reducing the negative impact of vibrations that occur during the drilling of dense layers. Application of the integrated approach to solve the problems, which took place during the construction of wells on the Achimov deposits, has significantly reduced: the number of equipment failures, non-productive time. Meanwhile increased the mechanical rate of penetration and drilled distance in one trip, which in general has significantly reduced the time of well construction.

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Casing and liner running and cementing operations in high angle wells with long open hole sections pose seemingly diverse sets of challenges irrespective of location and drilling environment. The fluvial loose formations predominant in the arctic region of Russia and most parts of Siberia provides more than adequate tests and constraints to modelling, understanding and accommodating the risks associated with such operations as this. This is further complicated with no reliable nor consistent information regarding representative geo-mechanics models or failure plains within the region.This paper looks at modelling casing 1,2,3,4 running operations and the impact of perceived friction factors and choice of accessories on the overall out come of the operation. The objective is to better understand the modelling constraints and the importance of certain parameters and assumptions in the final solutions. Successes, failures and lessons learned will be articulated to provide key best practices or design considerations for similar or future projects. Furthermore, we will also evaluate the technologies available within the area and the impact of technology adoption on both the ability to land casing/liner and provide adequate cementing.