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Title: Resolving pore-space characteristics by rate-controlled porosimetry

By monitoring the mercury capillary pressure in rate-controlled porosimetry (intrusion) experiments, new information regarding the pore space of a rock sample has been obtained. With this technique, called an apparatus for pore examination (APEX), it is now possible to resolve the pore space of a rock sample into two interconnected parts. One part identifies the individual pore systems (pore bodies), which are low-energy sumps or regions of low capillarity. The other part corresponds to the pore throats that interconnect with pore systems. New capillary-pressure curves have been obtained by partitioning the total capillary-pressure curve (normal capillary-pressure curve) into two subcurves: the subison capillary-pressure curve, which details the distribution of pore bodies, and the rison capillary-pressure curve, which details the distribution of pore throats. The authors present APEX data on Berea sandstone and San Andres dolomite that show the volume distribution of low-capillarity regions within the pore space of these rocks. These regions of low capillarity are the principal pore-space regions that trap the residual nonwetting phase upon imbibition of a strongly wetting fluid, as measured by toluene/air systems. The residual nonwetting-phase saturations as determined by the APEX method and by the toluene/air method are in excellent agreement. Thus, the detailedmore » volume distribution of pore systems responsible for trapped nonwetting-phase saturation is determined from APEX measurements, which can have important implications for EOR.« less
Authors:
;
Publication Date:
OSTI Identifier:
6162107
Resource Type:
Journal Article
Resource Relation:
Journal Name: SPE (Society of Petroleum Engineers) Format. Eval.; (United States); Journal Volume: 4:1
Research Org:
Shell Development Co. (US)
Country of Publication:
United States
Language:
English
Subject:
02 PETROLEUM; RESERVOIR PRESSURE; EVALUATION; RESERVOIR ROCK; POROSITY; SAMPLING; AIR; ENHANCED RECOVERY; EXPERIMENTAL DATA; MEASURING METHODS; OIL SATURATION; PHASE STUDIES; TOLUENE; ALKYLATED AROMATICS; AROMATICS; DATA; FLUIDS; GASES; HYDROCARBONS; INFORMATION; NUMERICAL DATA; ORGANIC COMPOUNDS; RECOVERY; SATURATION 020200* -- Petroleum-- Reserves, Geology, & Exploration; 020300 -- Petroleum-- Drilling & Production