Organic matter detection in shale reservoirs using a novel pulse sequence for T1-T2 relaxation maps at 2 MHz

SILLETTA, EMILIA V.; VILA, GABRIELA S.; DOMENÉ, ESTEBAN A.; VELASCO, MANUEL I.; BEDINI, PAULA C.; GARRO-LINCK, YAMILA; MASIERO, DIANA; MONTI, GUSTAVO A.; ACOSTA, RODOLFO H.

FUEL

ELSEVIER SCI LTD

Año: 2022 vol. 312

0016-2361

uantification of organic matter and fluids contained in oil source rocks from shale plays is a fundamental goal for the petrophysical and geochemical assessment of the production potential of a well. Laboratory 1H nuclear magnetic resonance (NMR) is a fast, reliable, and non-destructive method widely used in the oil industry. Measurement of T1-T2 correlation maps have been found to be critical for identifying the presence of solid organic matter, liquid hydrocarbons, and brine in these formations. However, the inherent long echo times associated with standard laboratory equipment for large sample volume challenge the detection of contribution from kerogen and viscous bitumen. In this work, we use a commercial low field NMR rock-core analyzer where a novel T1- T2*&T2 pulse sequence is implemented to enable the detection of solid organic matter by acquiring the free induction decay after the first excitation pulse. This acquisition is followed by a train of refocusing pulses that genera