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This article describes experience and results of TAML-3 penta-lateral (5-lateral) Fishbone type well construction at East-Messoyakha field. Trial work has been conducted to determine technical and economical feasibility of fishbone well construction. East - Messoyakha field has very complex geological structure. According to field sedimentary conditions there are 3 major deposition cycles in primary PK 1-3 formation - «А», «B» и «С». Cyclite «B» has a high degree of discontinuity that leads to low production efficiency of horizontal wells. Hydrodynamic modelling has shown multilateral well technology to be perspective in terms of increase of vertical association coefficient. Utilization of multilateral well technology is very perspective in geological conditions of East-Messoyakha field, it will also increase efficiency of reserves development compared to conventional horizontal wells. During completion concept selection and planning stage, different options have considered. TAML-3 level have been selected for a multilateral junction. Lateral trajectories well paths were planned to cross sub-layers and turn in azimuthal direction. Multilateral ERD well construction required multiple technical solutions to be implemented in order to successfully complete the project: running 7" casing in 800 horizontal section, utilization of OBM and its re-use, running lateral liners in two trips. Successful project execution of penta-lateral allows to solve the following challenges:extend reservoir coverage and increase of effective well radius in heterogeneous layerssimultaneous drainage in different layersdecrease the risk of production loss due to lateral hole collapse Cased fishbone multilateral well proved its effectiveness after 6-months production. It is also a logical continuation of company’s technological development. The paper also discusses possible options for further advancement.

This article deals with the issues related to development of petroleum resources of Western Siberia and looks at one of the most promising development targets – reservoirs of the Achimov Formation. In particular, it discusses geological features of the Achimov rocks, and the difficulties faced by oil companies in development of the Achimov reservoirs due to their low economic viability if traditional approaches to well construction are applied. To make development of such reservoirs economical, new and non-trivial solutions need to be looked for. One of the most promising of them is considered to be multi-hole wells the construction of which allows oil companies to improve the Capex to cumulative production ratio. At the pre-FEED stage the project, geological, hydrodynamic and geomechanical models of the reservoir were built, the most efficient borehole parameters and trajectories were defined, and the optimal hydraulic frac design, number of stages and parameters were selected. The article describes specifics of the work carried out when preparing for pilot tests of the technology, such as:requirements for defining the well profile and selecting the optimal lifting capacity of the drilling rig,selection of a suitable complexity level for the double-hole well design among those considered which meets the drilling requirements,performance of bench tests to confirm operability of the TAML-3 equipment. Further, the article describes results of drilling, completing and commissioning the first double-hole well at the Vyngayakhskoye field, discusses the issues faced when using the completion equipment at the TAML-3 level, and the lessons learned from this project. It also presents results of putting the double-hole well on-stream and compares its production characteristics with those of single-hole horizontal wells drilled within the same well cluster. The experience gained has shown that building the discussed type of wells is technically feasible, and there is a wide potential for improving efficiency of this work through respective organizational and technical measures. The conclusion to this article describes Gazprom Neft long-term plans to build several new wells of this design, and the technology development options such as increasing the length of horizontal segments for both holes and using high-rate multi-stage hydraulic fracturing.