An Experimental Study of Elastic Wave Propagation an Isotropy and Permeability an Isotropy In an Illitic Shale.

Abstract

f T99S, %d@Y of Pel,ofaum Enginaers, Inc. This papar was prapamd for presantatmm at !he SPHISRM Eurock '98 held in Trondhelm, Nonvay, 8-10 July 1S9SThis papar was aelectad for presantatica by an SPE Program Commiftee Iolfowing revfaw of infomlafim cantalnad In an abstract submittad by the aulhorts) Contents of the papar, as -ted. haw nOl baan rwdavmd by the Swiety of Petroleum Enginaars and are Sub@cl to mrraction by the aumor{s) Tha material, as presaniad, dons not nacessmily raflact any pdaftion of the SMety of Petroleum Engmears, its officers, or members PaIMrs presanted at S.PE nmaiings ara subfect to publication revlaw by Editorial Committees of the %ciety of petroleum Englnaars Eiactronlc reproduction, distribution, or storage of any part of this papa for cannwrmal purposes wthout the Mitten mnsant of the S@ety of Petroleum Engineers is prohibttad PennlssIm to reprakum in print IS restritied to an abstract of not more than S00 words+ illustrations may not IX cupiad. The abstracl must con!a!n conspicuous acknovdadgmant of where and by MW+_I? tha papar was presentad Wme Librarian, SPE. P 0. 8QX S3S8S6 Ricf!ardxm. TX 7!S0S3-3SS6, u. S.A., fax Ot-972-952+M35 AbstractShales are highly anisotropic and are generally characterized by very low permeabilities. In this paper we report results of an experimental study of the relationship between elastic wave propagation anisotropy and permeabilityy anisotropy of an illitic shale.Elastic wave velocity was measured as a function of angle reIative to the bedding plane orientation. Radial compressional and shear wave velocities were measured around the circumference of a core taken parallel to the bedding of the shale. The shale was highly anisotropic.Permeability measurements were then taken for cores oriented in the directions of the maximum and minimum velocities.The permeability was measured using a novel steady-state-flow permeameter capable of measuring extremely low flow rates of water, brine, or oil. At low effective pressure the shale was highly anisotropic, but the anisotropy reduced to zero at high effective pressure.We compare the shale results with those from measurements on a sandstone and a tuff, where permeability anisotropy is maintained even up to the highest effective pressures used.

A Model and Measurement Technique for Liquid Permeability of Tight Porous Media Based on the Steady-State Method

“…18,19,28−32 This method is also very sensitive to fluid leakage and temperature fluctuations. 5,23 In addition, Lyu et al 33 and Sander et al 5 stated that the pulse-decay method may overestimate permeability compared to the steady-state method. Rushing et al 34 investigated the reason behind this discrepancy and concluded that this might be related to fundamental problems with the unsteady-state methodology.…”

“…On the other hand, when a constant flowrate mode is applied for permeability measurement, it takes too long to arrive at equilibrium pressure. − Lasswell reported that 6 to 8 weeks is required until a reasonable flow equilibrium is achieved when a light oil is used for measurement of permeability in the range of nanodarcy. Jones and Meredith, Morrow and Lockner, and El-Dieb and Hooton measured permeability of tight rocks in the range of nanodarcy in 15 to 160 h by applying only one pressure gradient across the sample. In all these studies, the core permeability is calculated based on only one flowrate value.…”

“…The pulse-decay technique, which is a transient method, appears to be the most common method to measure permeability of tight rocks . Various analytical solutions have been proposed for calculating permeability using the measured pulse-decay data that may lead to nonunique results. ,,− This method is also very sensitive to fluid leakage and temperature fluctuations. , In addition, Lyu et al . and Sander et al stated that the pulse-decay method may overestimate permeability compared to the steady-state method.…”

A numerical investigation on the performance of hydraulic fracturing in naturally fractured gas reservoirs based on stimulated rock volume

“…;Jones et al (1998);Benson et al (2010);Fazio et al (2017);Walsh (1981);Kneafsey et al (2018)). In this section, the failure caused by the progress of the hydraulic fracture occurs according toFig.…”