Determine the depth of gas hydrate formations in oil wells regarding the operating mode and composition of associated gas

About the authors:

Dmitry A. Molchanov, Chef Specialist, Tyumen Prtroleum Research Centre
Albina V. Shirshova, Cand. Sci. (Phys.-Math.), Associate Professor, Department of Multiphase Systems Mechanics, Institute of Physics and Technology, Tyumen State University; albstain@gmail.com

Svetlana S. Politova, assistant, Department of Multiphase Systems Mechanics, Phusics and Technical Institute Tyumen State University

Abstract:

Formation of hydrate deposits (obstructions) in the producing oil well borehole is one of the urgent problems facing the oil and gas industry in the northern regions. The oil fl ow within these obstructed sections may slow down or stop completely, which is unacceptable for the field development. This paper studies the method aimed at predicting this event based on calculation of pressure and temperature distribution along the wellbore in accordance with the general equations of fluid dynamics and thermal physics. The sections where hydrate formation is possible are predicted by means of hydrate-existing condition diagrams in the «pressure- temperature» coordinates, if we calculate the PT conditions in a wellbore and associated petroleum gas composition. It is shown that the consideration of associated gas composition displaces the projected depth of gas-hydrate formations for hundreds of meters.

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