Linear pressurization method for determining hydraulic permeability and specific storage of a rock sample

Abstract

S U M M A R YWe studied the methodology and applicability of linear pressurization for determining simultaneously hydraulic permeability and specific storage of a rock sample. We analytically solved the governing equation for 1-D pressure diffusion through a homogenous, isotropic cylindrical rock specimen located between a downstream and an upstream reservoir considering linear pressurization of the upstream fluid as the boundary condition. The solution consists of a transient and a steady state for which both differential pressure between the two reservoirs and injection rate at the upstream reservoir assume constant values. Since the steady-state differential pressure is linearly proportional to the compressive storage of the downstream reservoir, tests conducted with a systematic variation of the size of the downstream reservoir permit determining permeability and specific storage from the intercept and slope of the linear relationship. Alternatively, simultaneous measurement of differential pressure and fluid injection rate at steady-state conditions provides a basis for calculation of the hydraulic properties as previously presented for linear injection. Experiments were performed on Fontainebleau sandstone samples to document the feasibility of the method. The determined storage capacity value is used to calculate various poroelastic parameters, such as bulk and pore-space compressibility, Skempton and the effective pressure coefficient.

Experimental Investigation into the Scale Dependence of Fluid Transport in Heterogeneous Rocks

“…Our test arrangement consisted of a specimen placed in a confining pressure vessel and connected to a downstream and an upstream reservoir equipped with servo-hydraulically controlled intensifiers (see SONG and RENNER, 2006). Porous metal discs (SIKAR S) of 3 mm thickness with a porosity of 31%, a permeability of >10 )12 m 2 , and a pore diameter in the range of 7 to 14 lm at the sample ends served a dual purpose.…”

Axial flow hydraulic pulse testing of an argillaceous limestone

“…Reviews of other applications of the hydraulic pulse tests for permeability testing are given by Selvadurai and Carnaffan (1997) and Gross and Scherer (2003) (measurement of permeability of cementitious materials) and Selvadurai et al (2005) (measurement of permeability of granite cylinders, measuring 405 mm in diameter) and Song and Renner (2006) (permeability of Fontainebleau Sandstone).…”

Theoretical Analysis of One-Dimensional Pressure Diffusion from a Constant Upstream Pressure to a Constant Downstream Storage

“…For a general experimental setup (Fig. 1), the main source of uncertainty comes from the measurement of flow when the flow occurs only in response to a change in compressive storage (SONG and RENNER 2006). Other sources of error (pressure reading and sample dimension) are negligible in terms of uncertainty analysis.…”

“…(2) can be solved to predict the timelapse pressure distribution along the sample. The solution is generally composed of two parts: an asymptotic solution independent of time, and a transient solution that is a negative exponential function of time (HSIEH et al 1981;SONG et al 2004;SONG and RENNER 2006).…”