Use of 3D Images to Evaluate Formation Damage Induced by Montmorillonite Fines in Porous Media Systems
Abstract
Formation damage costs oil and gas industry $140 billion/year in lost productivity, this
is a key challenge to Qatar, the world's largest LNG exporter. During production from
a well, multiphase flow foster drag forces to mobilize fine particles from within the
subsurface. Fine' migration can alter the gas flow, clogging pores and disconnecting gas
pathways. Understanding fines influence is a complex challenge due to the reservoirs'
porous media heterogeneity. Microtomography of sand sediments provides a standardized
approach to study the fines impact. X-Ray microtomography of two repacked sand
cylinders was carried at Argonne National Lab synchrotron. Rounded silica sand was
mixed with hydrophilic swelling montmorillonite clay. High and low fines concentrations
were mix--ed with the sand then deposited into five layers. Initially, samples were fully
saturated, then gas was injected, the sediments were scanned before and after injection.
At first, fines were suspended in the brine, but after injection were retained on the gasbrine
interface, and their concentration in the brine increased. Gas injection divided
pores and throats, reducing their average size. Contrarily, main gas pathways increased
in size but were disconnected in the sediment with high fines concentration. Fines caused
increased capillary pressure and lowered the sediment permeability.
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- Civil and Environmental Engineering [851 items ]
- Theme 3: Geotechnical, Environmental, and Geo-environmental, Engineering [21 items ]