Pressure Coring, A New Tool for Unconventional Oil & Gas Characterization

Wood, Mark R.; Sinclair, Jeff; Bjorum, Matt

Determining accurate oil saturations, gas volumes, content and deliverability are critical when attempting to assess the economics of unconventional plays. These determinations rely heavily on the analysis of freshly cut core. Accurate oil, water, and total saturations are dependent on the ability of the laboratory to analyze fresh core. The total gas content and gas composition derived from cores are known to contain uncertainties as a result of the lost gas which escapes the core during the ascent out of the hole, hence leaving a data gap which must be accounted for theoretically in conventional core analysis.

In order to eliminate this issue a new wire line and/or conventionally tripped pressure core tool has been developed. This pressure core system has proven to be an effective means to recover all gas and liquids associated with a ten foot long three inch diameter core. The tool can now obtain a direct measurement of total gas content by encapsulating the core in a pressure vessel down hole or by recovering the gas in canisters during POOH. All liquids are recovered and oil can be separated and added to the average porosity and oil saturation for the volume of core recovered. More accurate oil and water saturation data are also obtained. Available case histories will be summarized.

AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013