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Title: Semiautomated method for cation-exchange capacity determination of reservoir rocks

The presence of significant amounts of clay in tight-gas sand formations makes the determination of cation exchange capacities (CEC) important for electric-log, self potential (SP), and gamma ray log interpretation. In the past, CEC measurements have been difficult and time-consuming to obtain. However, an automated method that avoids many difficulties of other techniques while determining the CEC's of many samples at one time has been described by Worthington. This work is a modification of the work done by Worthington. Easily assembled commercial equipment instead of specially built equipment is used to agitate rock samples contained in dialysis membrane bags during ion exchange with barium acetate solution and during washing of the samples to remove excess barium ions. Barium acetate is used as the source of barium ions instead of barium chloride, which is used in Worthington's procedure, to avoid corrosion of the stainless steel equipment. The amount of barium ions on the rock samples is then determined by conductometric titration with magnesium sulfate. The titration procedure is not automated. In addition, the use of the barium ion method was extended to samples with CEC values an order of magnitude lower than those determined by Worthington.
Authors:
; ;
Publication Date:
OSTI Identifier:
5500259
Resource Type:
Journal Article
Resource Relation:
Journal Name: Soc. Pet. Eng. AIME, Pap.; (United States); Journal Volume: 23:2
Research Org:
U.S. DOE
Country of Publication:
United States
Language:
English
Subject:
02 PETROLEUM; RESERVOIR ROCK; ION EXCHANGE; PERMEABILITY; SANDSTONES; ABSORPTION; ACETATES; AMMONIUM COMPOUNDS; AUTOMATION; BARIUM COMPOUNDS; CORROSION; DIALYSIS; ELECTRIC LOGGING; GAMMA LOGGING; MAGNESIUM SULFATES; SP LOGGING; STAINLESS STEELS; TITRATION; WATER; ALKALINE EARTH METAL COMPOUNDS; ALLOYS; CARBOXYLIC ACID SALTS; CHEMICAL REACTIONS; CHROMIUM ALLOYS; CORROSION RESISTANT ALLOYS; HYDROGEN COMPOUNDS; IRON ALLOYS; IRON BASE ALLOYS; MAGNESIUM COMPOUNDS; OXYGEN COMPOUNDS; RADIOACTIVITY LOGGING; ROCKS; SEDIMENTARY ROCKS; SEPARATION PROCESSES; STEELS; SULFATES; SULFUR COMPOUNDS; WELL LOGGING 020200* -- Petroleum-- Reserves, Geology, & Exploration