Gas flow mechanisms in fractured low permeability reservoirs.

Ogoun, Evans; Aisueni, Florence; Ogunlude, Priscilla; Gobina, Edward

Abstract

The exploration and production of unconventional natural gas reservoirs has enhanced the gateway to the diversification of economic activities from oil. However, the gas industry faces some major variations in the storyline in different parts of the world with the United State of America, China and Middle East in full swing unconventional gas revolution. The matrix permeability of unconventional gas reservoirs (shales, coalbed, and tight sand) is usually very low, less than 0.1 milli Darcy (mD) and a matrix porosity of less than 10%. As a result of the low porosity and permeability, unconventional reservoirs in most cases require hydraulic fracturing/fracking to liberate gas at economical quantity to the wellbore. The reservoirs produce at a low flow rate under radial flow conditions without hydraulic fracturing, but after a successful fracture treatment the mechanism of the gas flow in the formation changes from radial flow to linear flow. These flow regimes must be considered to account for the transport mechanisms from macroscopic to the microscopic scale. Under an isothermal condition the transportation of gas in a porous media involves viscous flow, Knudsen diffusion and molecular diffusion. The long-term productivity of fractured gas reservoirs is directly controlled by the matrix flow and due to the low permeability of these reservoirs the flow velocity within the matrix tends to be very low. The research is designed to present a unified mathematical model to efficiently cover for the complexity in the flow mechanisms that characterize hydraulically fractured low permeability reservoirs. This will allow for sound operational decision making, maximize business opportunities and limit operational risks associated with exploration and exploitation of low permeability gas reservoirs.

Citation

OGOUN, E., AISUENI, F., OGUNLUDE, P. and GOBINA, E. 2021. Gas flow mechanisms in fractured low permeability reservoirs. Presented at 2021 International congress of Scientific Advances (ICONSAD'21), 22-25 December 2021, [virtual conference].

• Presentation Conference Type: Lecture
• Conference Name: 2021 International congress on scientific advances (ICONSAD '21)
• Conference Location: [virtual conference]
• Start Date: Dec 22, 2021
• End Date: Dec 25, 2021
• Deposit Date: Jan 7, 2022
• Publicly Available Date: Feb 18, 2022
• Keywords: Nanoporous; Fractured; Low permeability; Knudsen diffusion
• Public URL: https://rgu-repository.worktribe.com/output/1563482
• Publisher URL: https://en.iconsad.org
• Additional Information: Abstract published as:; OGOUN, E., AISUENI, F., OGUNLUDE, P. and GOBINA, E. 2021. Gas flow mechanisms in fractured low permeability reservoirs. In Proceedings of 2021 International congress of Scientific Advances (ICONSAD'21), 22-25 December 2021, [virtual conference]. Turkey: ICONSAD [online], page 1057. Available from: https://tinyurl.com/2p8uy2rh