No abstract

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.

A workflow was developed for effectively handling the development challenges in the Yamal oil and gas province of Western Siberia. The workflow integrates geomechanics with efficient drilling practices and leads to the implementation of an engineered drilling system (EDS). The workflow for development in the Yamal region encompasses phases from modeling to drilling practices, incorporating an understanding of challenges faced and lessons learned from previous drilling. The majority of Achimov operations in the Yamal region have been conducted in the Urengoy gas condensate field, which is divided into different blocks. The Achimov deposits are deep (true vertical depth is about 3,750 m), exhibit abnormally high formation pressure (over 600 atm), and contain multiphase hydrocarbons with the presence of heavy paraffins. Unstable shale formations must be drilled prior to penetrating the Achimov itself. These challenges affect drilling efficiency and interfere with the well construction schedule. The Achimov formations present two main challenges to horizontal drilling: wellbore instability leading to stuck pipe incidents in the build section or inability to run liner/casing to total depth and loss circulation, potentially compromising well delivery and project objectives. Thus, previous drilling has shown that developing and producing from these enigmatic resources requires more than just horizontal wells and hydraulic fracturing. Companies are aggressively pursuing Achimov deposits, hoping to extract additional gas and gas condensate volumes from the declining fields and to implement a strategy to raise natural gas production. Successful operations require an integrated approach, using multiple data sources, to determine the key parameters needed to understand the Achimov formations and extract the hydrocarbons. Among the successes, an operator company for Urengoy field demonstrated how developing a mechanical earth model (MEM) of the reservoir and continually improving processes paid big dividends. By implementing the EDS approach, unique results have been achieved in drilling and completion of Achimov horizontal wells. Outstanding drilling performance in Achimov horizontal wells has led to a revision of the field development plan.

Новые технологии открывают новые возможности и новый этап в эффективности бурения протяженных горизонтальных скважин на Самбургском месторождении В. Крецул, С. Дымов и П. Доброхлеб, Schlumberger, А.Миленький, О.Тарасов, ОАО "Арктикгаз" Авторское право 2015 г., Общество инженеров нефтегазовой промышленности Этот доклад был подготовлен для презентации на Российской нефтегазовой технической конференции SPE, 26 -28 октября, 2015, Москва, Россия.Данный доклад был выбран для проведения презентации Программным комитетом SPE по результатам экспертизы информации, содержащейся в представленном авторами реферате. Экспертиза содержания доклада Обществом инженеров нефтегазовой промышленности не выполнялась, и внесение исправлений и изменений является обязанностью авторов. Материал в том виде, в котором он представлен, не обязательно отражает точку зрения SPE, его должностных лиц или участников. Электронное копирование, распространение или хранение любой части данного доклада без предварительного письменного согласия SPE запрещается. Разрешение на воспроизведение в печатном виде распространяется только на реферат объемом не более 300 слов; при этом копировать иллюстрации не разрешается. Реферат должен содержать явно выраженную ссылку на авторское право SPE. РезюмеОптимизация процесса и сокращение времени бурения является одной из сложных и ключевых задач для многих компаний-операторов а также сервисных подрядных организаций.

Major gas fields in West Siberia have been depleted by 50-80%, and field operators are actively searching for ways to reverse declining production and access new gas deposits previously ignored given their complexity. One such hard-to-recover deposit is the Turonian play. With total gas reserves reaching approximately 3 trillion cubic meters, Turonian gas is encountered in nearly the entire Northern part of West Siberia.Developing the Turonian deposits presents the following challenges:• Poor reservoir properties and low well productivity; • Significant reservoir heterogeneity and facial variability along the section and area-wise, which complicates well placement operations for an optimal gas extraction; • Low formation temperature and abnormally high pressure, which may require well operations in a near-hydrated regime; • High clay content, which leads to formation damage when water-based fluids are being used in reservoir drill-in operations.Drilling of Turonian horizontal wells is complicated by a narrow safe mud weight window, geology uncertainties, and high sensitivity of borehole stability to well trajectory.Analysis of Turonian well construction experience has identified technological solutions in two main areas:1. Provide high-quality hole in all sections of horizontal well, including lateral sections, with length more than 800 m (to run safely casing to planned depths with followed multi stage hydraulic fracturing in horizontal section). 2. Minimize formation damage, thereby preserving potential well productivity in a formation with a high clay content in wide range of temperature and pressure conditions.Core samples from the Turonian formations were tested to determine mechanical, elastic, and other rock properties. From these results different mud types were evaluated for formation damage and impact on the mechanical and elastic rock properties.1. Geomechanics is a vital part for productive drilling; 2. Optimal selection of dril-in and fracturing fluid played a critical part in achieving the project objectives; 3. Integrated approach to drilling system design and close cooperation between all team participants are the key success factors in delivering technically complex projects; 4. The combination of fit for purpose technologies into an effective drilling system can provide cost effective solutions for field development with region specific challenges and traditional technology limiters.