Relationships between permeability, porosity and pore throat size in carbonate rocks using regression analysis and neural networks

Rezaee, Mohammad; Jafari, Alireza; Kazemzadeh, Ezatallah

doi:10.1088/1742-2132/3/4/008

Cited by 141 publications

(52 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…From these calculations, we obtain a first estimate of the effective bulk porosity of the RAPS at 32-35%, although this may be an overestimate, due to the finite volume of the partially ochre-filled supernatant water layer. hydraulic conductivity is controlled by the aperture of the throats (Doyen, 1988;Rezaee et al, 2006), connecting pore spaces, which can become clogged very easily, rather than by the aperture of the pores themselves (Heiderscheidt et al, 2008). The spread of values in Figure 3b also provides some impression of the accuracy of the hydraulic data obtained from analysis of these tracer tests, approximately 30% around the mean value.…”

Section: Previous Tracer Testsmentioning

confidence: 90%

Characterisation of hydraulic and hydrogeochemical processes in a reducing and alkalinity-producing system (RAPS) treating mine drainage, South Wales, UK

Taylor

Banks

Watson

2016

International Journal of Coal Geology

View full text Add to dashboard Cite

A series of tracer tests has been carried out in the compost and limestoneTan-y-Garn Reducing and Alkalinity-Producing System (RAPS), designed to treat iron-rich net acidic mine water (mean pH 6.18, Fe = 47 mg L . Electrical conductivity and major ion chemistry were monitored for a 170 hour period.Sodium exhibited a retardation of 1.15 to 1.2 in the RAPS medium relative to chloride, due to cation exchange. Simple 1-D advection-diffusion analytical modelling succeeded in simulating the early portion of tracer breakthrough in the RAPS effluent. More complex analytical modelling, accounting for (i) mixing and dilution effects in the supernatant water input signature and (ii) matrix diffusion effects, was found to be required to adequately simulate the later-stage tail of the breakthrough curve in the RAPS effluent. 2 KeywordsTracer test, alkalinity, mine water, artificial wetland, matrix diffusion, ion exchange 3 Introduction What is a Reducing and Alkalinity-Producing System (RAPS)?It is common and cost-effective to treat iron-rich mine waters (Banks and Banks, 2001; PIRAMID Consortium, 2003;Sapsford and Watson, 2011) by passive, aerobic methods, such as aerobic sedimentation basins or wetlands.These function by the oxidation of ferrous to ferric iron, followed by the hydrolysis and precipitation of ferric iron from the water. This net process can be described by equation (1) The overall oxidation and hydrolysis reaction is thus acid-producing (2 moles of protons released for every mole of ferrous iron oxidised and precipitated).However, the hydrolysis and precipitation reaction is strongly pH-dependent: if the pH becomes too low, the hydroxide precipitate will not form. Thus, it is important that sufficient alkalinity is available in the water to absorb the protons produced and to buffer the pH at a reasonably high level (Hedin et al., 1994a;Younger et al., 2002). Alkalinity can be added actively, by dosing the influent mine water with hydroxide or carbonate. However, it can also be released passively by allowing the mine water to flow through limestone drains before entering the aerobic treatment lagoons or wetlands (PIRAMID Consortium, 2003). The limestone slowly dissolves, releasing bicarbonate alkalinity to the water. If the water contains oxygen, however, ferric hydroxide may precipitate out in the limestone drains, "armouring" the limestone clasts and inhibiting further dissolution (Hedin et al., 1994b;Cravotta and Trahan, 1999;Watzlaf et al., 2000a;Bernier et al., 2001). Thus, it is important to strip oxygen from the water before it enters the limestone drain, ensuring that iron remains in its ferrous form (Equation 2). This is most effectively done by a layer with a high organic content and thus a high oxygen demand -for example, a compost layer (represented by CH 2 O in equation (2)). On exiting a RAPS, the mine water will typically:(i) pass through a re-aeration system, such as an aeration cascade, before entering(ii) a system of aerobic treatment lagoons and/or wetlands, where the iron conte...

show abstract

Section: Previous Tracer Testsmentioning

confidence: 90%

Characterisation of hydraulic and hydrogeochemical processes in a reducing and alkalinity-producing system (RAPS) treating mine drainage, South Wales, UK

Taylor

Banks

Watson

2016

International Journal of Coal Geology

View full text Add to dashboard Cite

show abstract

“…Permeability is related to porosity in a complex way that is not well known (Rezaee et al, 2006)-permeability decreases with increasing depth in porous media, and the relationship between permeability and porosity is modeled to be a power law (David et al, 1994). However, permeability can also vary widely at a given depth due to mineralogy, fracturing, grain cementation, and so on.…”

Section: Appendix Dmentioning

confidence: 99%

An Extensive Phase Space for the Potential Martian Biosphere

Jones

Lineweaver

Clarke³

2011

Astrobiology

View full text Add to dashboard Cite

We present a comprehensive model of martian pressure-temperature (P-T) phase space and compare it with that of Earth. Martian P-T conditions compatible with liquid water extend to a depth of *310 km. We use our phase space model of Mars and of terrestrial life to estimate the depths and extent of the water on Mars that is habitable for terrestrial life. We find an extensive overlap between inhabited terrestrial phase space and martian phase space. The lower martian surface temperatures and shallower martian geotherm suggest that, if there is a hot deep biosphere on Mars, it could extend 7 times deeper than the *5 km depth of the hot deep terrestrial biosphere in the crust inhabited by hyperthermophilic chemolithotrophs. This corresponds to *3.2% of the volume of present-day Mars being potentially habitable for terrestrial-like life.

show abstract

“…The IP logging instrument can obtain the polarization decay potential (Guan et al 2010;Li et al 2011) which contains very rich underground information. The RTS inverted from the IP decay potential can be used to analyze the pore size distribution of the strata, and then to make assessments on the rock permeability, the amount of oil or water storage, and so on (Liu et al 2014a, b;Rezaee et al 2006;Binley et al 2005;Zimmermann et al 2008;Gurin et al 2013;Beckett and Augarde 2013;Li et al 2010). A lot of research work has been carried out on the RTS, including inversion algorithms (Moody and Xia 2004;Xiao et al 2012;Chen et al 2013;Jang et al 2014;Florsch et al 2014), determining the appropriate number of relaxation time constants and its distribution (Tong et al 2004;Buecker and Hoerdt 2013;Revil et al 2014).…”

Section: Introductionmentioning

confidence: 99%

Research into the inversion of the induced polarization relaxation time spectrum based on the uniform amplitude sampling method

et al. 2016

View full text Add to dashboard Cite

The induced polarization relaxation time spectrum (RTS) reflects the distribution of rock pore size, which is a key factor in estimating the oil or water storage capacity of strata. However, as the data acquisition and transmission abilities of well logging instruments are much limited due to the underground environment, it is necessary to explore suitable sampling methods which can be used to obtain an accurate RST with less sampling data. This paper presents a uniform amplitude sampling method (UASM), and compares it with the conventional uniform time sampling method (UTSM) and logarithm time sampling method (LTSM) in terms of the adaptability to different strata, RTS inversion accuracy, and stratum vertical resolution. Numerical simulation results show that the UASM can obtain high inversion accuracy of RTS with different kinds of pore size distribution formation, with high dynamic ranges of pore size, and with a small number of sampling points. The UASM, being able to adapt to the attenuation speed of polarization curve automatically, thus has the highest vertical resolution. The inversion results of rock samples also show that the UASM is superior to the UTSM and LTSM.

show abstract

Relationships between permeability, porosity and pore throat size in carbonate rocks using regression analysis and neural networks

Cited by 141 publications

References 18 publications

Characterisation of hydraulic and hydrogeochemical processes in a reducing and alkalinity-producing system (RAPS) treating mine drainage, South Wales, UK

Characterisation of hydraulic and hydrogeochemical processes in a reducing and alkalinity-producing system (RAPS) treating mine drainage, South Wales, UK

An Extensive Phase Space for the Potential Martian Biosphere

Research into the inversion of the induced polarization relaxation time spectrum based on the uniform amplitude sampling method

Contact Info

Product

Resources

About