Methods Improve Shale Core Analysis | SLB
Industry Article
Location
United States, North America
Publication
American Oil & Gas Reporter
Publication Date
11/30/2012

Methods Improve Shale Core Analysis

 

Gas shales have become an important resource for the production of hydrocarbons in North America, and are being explored as a resource on other continents as well, based on their rapidly increased importance to the North American market and promise to boost domestic production elsewhere. Regardless of where in the world they are being explored, gas shales share some fundamental properties that make them virtually impossible to analyze with conventional core analysis methods or conventional petrophysical models based on log data. These properties are basically that gas shales are tight, with permeabilities in the tens to hundreds of nanoDarcies, have low (effective) porosity, typically less than 10 percent, and have high kerogen and clay content. While there are some variations of these themes (e.g. shales with higher detrital input, making them siltier or silty-laminated), in general the tightness of the rock and abundance of clay minerals and kerogen pervades, and that causes a number of challenges to analysis. New analytical methods have been developed to evaluate cores from gas shale reservoirs by using crushed material to enable better access to the pore space, a high-throughput retort system practical for commercial-scale analysis to separately measure free/bound/structural water volumes, visually distinguish water from oil, and pressure transient analyses to determine permeability.

Methods Improve Shale Core Analysis

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