1887

Abstract

Nuclear magnetic resonance (NMR) has proven a good technique for measuring pore size distribution in reservoir rocks. The use of low field NMR together with sonic and electrical resistivity measurements, can contribute to illustrate the effect of adsorbing ions on chalk elasticity. NMR is useful for the study of the physical and chemical phenomena within saturated cores and sonic velocity is intimately connected to density and elastic constants of the rock. In this study we relate NMR data to changes in P-wave velocity due to ion adsorption. Core plugs from outcrop Stevns chalk, of ~45% porosity, were divided into groups of three and each group was saturated either with deionized water, calcite equilibrated water, or sodium chloride, magnesium chloride and calcium chloride solutions of the same ionic strength. Saturation with solutions that contain divalent ions caused major shifts in the distribution of the relaxation time. Core samples saturated with calcium chloride solution relaxed slower and those saturated with magnesium chloride solution relaxed faster than the rest of the samples. Along with the changes in relaxation the samples experienced smaller velocities of elastic waves when saturated with MgCl2 solution. Rock samples saturated with brines containing salts experienced lower electrical resistivity.

Loading

Article metrics loading...

/content/papers/10.3997/2214-4609.20130796
2013-06-10
2020-09-29
Loading full text...

Full text loading...

http://instance.metastore.ingenta.com/content/papers/10.3997/2214-4609.20130796
Loading
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error