The Experience of Drilling TAML-3 Well with Mutistage Fracturing on the Low Permeability Deposits of the West Siberia

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.