Estimating permeability using median pore-throat radius obtained from mercury intrusion porosimetry

Abstract

Mercury intrusion porosimetry (MIP) has been widely used to characterize the pore structure for various types of porous media. Several relationships between permeability and pore structure information (e.g., porosity and pore-size distribution) have been developed in the literature. This work is to introduce a new, and simpler, empirical equation to predict permeability by solely using the median pore-throat radius (r 50), which is the pore-throat radius corresponding to 50% mercury saturation. The total of 18 samples used in this work have a wide range of permeability, from 10 −6 to 10 3 mD, which makes the new equation more applicable. The predicted permeabilities by using the new equation are comparable with permeability values obtained from other measurement methods, as shown from ten samples with permeability data measured with nitrogen.

Pore structure and tracer migration behavior of typical American and Chinese shales

“…Some early measurements do not produce the effective tortuosity results, as the tortuosity calculation uses data points beyond the threshold pressure which is near 3-nm lower limit of the MICP instrument; recent measurements with more pressure measurement points consistently generate the tortuosity values e These two sample cubes are detected to contain micron size fractures which lead to larger median pore-throat diameters than their nonfractured duplicate sample Corporation, Norcross, GA). In addition, the MICP approach can also indirectly evaluate other pore characteristics, such as permeability and tortuosity (Webb 2001;Gao and Hu 2013). Each shale sample (rectangular prisms with the largest linear dimension at either 10 or 15 mm) was oven-dried at 60°C for at least 48 h to remove moisture, and cooled to room temperature (*23°C) in a desiccator with less than 10 % relative humidity before the MICP test.…”

“…As reported by Gao and Hu (2013), permeability for the shale samples was calculated from the MICP data by the method of Thompson (1986, 1987). Effective tortuosity s, another important parameter which indicates pore connectivity, can also be derived from MICP data (Hager 1998;Webb 2001).…”

Nanoscale Pore Structure Characterization and Permeability of Mudrocks and Fine-Grained Sandstones in Coal Reservoirs by Scanning Electron Microscopy, Mercury Intrusion Porosimetry, and Low-Field Nuclear Magnetic Resonance

“…The derivation of (4) is based on (2) and the Washburn equation (see (5)) which relates mercury injection pressures ( ) with radii of pores ( ) [59]. Because the contact angle ( ) between mercury and pore surface is 140 ∘ and the surface tension of mercury ( ) is 7.03 × 10 −3 psi⋅cm, (4) can be simplified to (6). Therefore, as long as the value of 2 is determined, 2 can finally be calculated by…”

“…Permeability calculation based on mercury injection pressure data is also an alternative method for direct determination of permeability through experiments. The following equation introduced by Katz and Thompson [1,5,6,61] can be employed to calculate the permeabilities of our investigated mudrock and finegrained sandstone samples using MIP data:…”

“…Among many controlling parameters, permeability is the key factor governing the fluid transport in geological media and thus has the most important impact on the migration and recovery process of coalbed methane [1][2][3][4]. Moreover, pore structure characteristics, for example, pore types, pore morphology, pore size distribution (PSD), and porosity, are closely related to the permeability of reservoir rocks [5][6][7]. Therefore, investigation on the pore microstructural characteristics and permeability of typical coal reservoir rocks is of great significance to ensure the safe and efficient exploitation of coal and coalbed methane.…”