Anisotropy of permeability and complex resistivity of tight sandstones subjected to hydrostatic pressure

Zisser, Norbert; Nover, G.

doi:10.1016/j.jappgeo.2009.02.010

Cited by 54 publications

(29 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The accuracy of such a method would, therefore, be dependent on the homogeneity of the original specimen from which the sub‐samples were cut. Some authors cut cubic samples aligned to observable rock fabric symmetries and then infer some aspect of resistivity anisotropy (Jouniaux et al 2006; Nabawy et al 2010; Zisser and Nover 2009). This method, however, suffers from two shortcomings: the first is an assumed and unverified link between optical rock fabric and DC/low frequency electrical properties, and the second is the use of a 2 electrode measurement system.…”

Section: Design Considerationsmentioning

confidence: 99%

“…In the case of CSEM this can include the effects of mineralogy and rock fabric at the micron and millimeter scale up to cyclical bedding on the scale of tens or even hundreds of metres. Electrical anisotropy at the centimetric scale has been observed in siliciclastic rocks (Nabawy et al 2010; Zisser and Nover 2009) and carbonates (Jouniaux et al 2006) and may be the dominant source of anisotropy seen in CSEM surveys (Ellis et al 2010a). Rock physics models exist for electrical anisotropy in siliciclastic rocks and carbonate rocks; for example, Ellis et al (2010b); Haro (2010).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Laboratory determination of the full electrical resistivity tensor of heterogeneous carbonate rocks at elevated pressures

North

Best

Sothcott

et al. 2013

Geophysical Prospecting

View full text Add to dashboard Cite

We describe a measurement system capable of determining the full resistivity tensor of core samples at elevated, geologically representative, pressures using a galvanic method. It is suitable for heterogeneous rocks where it is difficult to measure tensorial resistivity without bias from sample selection and heterogeneity. We demonstrate the efficacy of the system using both synthetic data and measurements on carbonate rock core samples. The apparatus employs a computer controlled array of 16 electrodes to inject current into, and measure boundary voltages on, a 5 cm diameter cylindrical sample. A computationally efficient FE algorithm is used to retrieve the full resistivity tensor from the measured voltages. The algorithm uses isotropic Finite Element code to calculate anisotropic solutions for samples of arbitrary geometry. Initial results from Jurassic limestone and Triassic dolomite samples, reveal cm‐scale heterogeneity and significant bulk anisotropy consistent with rock fabric observed in X‐ray Computed Tomography scan images.

show abstract

Section: Design Considerationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Laboratory determination of the full electrical resistivity tensor of heterogeneous carbonate rocks at elevated pressures

North

Best

Sothcott

et al. 2013

Geophysical Prospecting

View full text Add to dashboard Cite

show abstract

“…Previous works were based on deterministic approaches, which may lead to incorrect results in the presence of nonuniqueness in the inverse solution (e.g., in the presence of strong heterogeneities), and they were only focused on the in-phase conductivity/resistivity. Zisser and Nover (2009) investigate the complex resistivity tensor of tight rocks at frequencies >10 kHz. These frequencies are mostly higher than those investigated in the present work.…”

Section: Introductionmentioning

confidence: 99%

Laboratory determination of the complex conductivity tensor of unconventional anisotropic shales

2014

View full text Add to dashboard Cite

We developed a four-electrode acquisition system to measure the complex conductivity tensor of tight and anisotropic shale cores using an accurate impedance meter. The complex conductivity tensor was obtained by inverting complex electrical potential data (amplitude and phase) acquired over a distributed array of electrodes. Inversion of the acquired data was performed with a Markov chain Monte Carlo (McMC) sampler that can explicitly take into account the nonuniqueness of the inverse problem. This approach was validated with direct measurements of impedance tensor eigenvalues with a single-component measurement technique. Consistent results were obtained using these two methods validating those obtained through the McMC sampling strategy. Both the in-phase and quadrature conductivities were anisotropic with the same anisotropic ratio in agreement with a recently developed petrophysical model based on volume averaging. The type of anisotropy of the Bakken and Haynesville core samples was found to be transverse isotropic, with the anisotropic ratio on the order of 10. In-phase conductivity was found to be independent of frequency up to 100 Hz, while the magnitude of the quadrature conductivity increased with frequency in the range from 0.1 to 45 kHz. Both components were sensitive to water saturation. Surface conductivity could be reliably predicted from the quadrature conductivity in agreement with the model prediction. The relationship between surface and quadrature conductivities was independent on saturation and anisotropy.

show abstract

“…The blue, purple and orange diamonds or squares indicate the reservoir sandstones of group 1 while the graywackes of group 2 and our data are represented by black diamonds and red dots, respectively. LAF1989, JAL1992, F1957 and ZN2009 refer to Longeron et al (), Jing et al (), Fatt () and Zisser and Nover (), respectively (see text for more details).…”

Section: Discussionmentioning

confidence: 99%

Effective Pressure Law for the Intrinsic Formation Factor in Low Permeability Sandstones

Chen

Bernabé

et al. 2017

JGR Solid Earth

View full text Add to dashboard Cite

The effective pressure law for the intrinsic formation factor of low permeability sandstones from the Ordos Basin (northwest of China) was studied experimentally by measuring the electrical resistivity of brine saturated rock samples while cycling the pore and confining pressures, pp and pc. We used a 100,000 ppm NaCl solution so that the results could be directly interpreted in terms of the intrinsic formation factor F. The Response Surface method was used to construct a quadratic function of pp and pc fitting the experimental data, from which the coefficient α of the effective pressure law, peff = pc – αpp, was determined. We found that the coefficient α generally had low values, mainly from 0.2 to 0.4, thus contradicting the theoretical prediction that α should be equal to 1 for scale‐invariant properties, such as F, in linear elastic materials having a homogeneous solid matrix. Since the two underlying assumptions, linear elasticity and homogeneity of the solid matrix, are likely violated in reservoir rocks, we tried to assess their effects on α using simple analytical models, based on idealized geometries of the pore and solid phases. Analysis of these models suggests that non‐linear elasticity associated with the formation of solid–solid contacts in the compressed rocks (e.g., during closure of rough cracks or crack‐like pores along the grain boundaries), may be more effective in producing the low α values observed than inhomogeneity of the solid matrix.

show abstract

Anisotropy of permeability and complex resistivity of tight sandstones subjected to hydrostatic pressure

Cited by 54 publications

References 57 publications

Laboratory determination of the full electrical resistivity tensor of heterogeneous carbonate rocks at elevated pressures

Laboratory determination of the full electrical resistivity tensor of heterogeneous carbonate rocks at elevated pressures

Laboratory determination of the complex conductivity tensor of unconventional anisotropic shales

Effective Pressure Law for the Intrinsic Formation Factor in Low Permeability Sandstones

Contact Info

Product

Resources

About