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

Mohammadi, Mohaddese; Vila, Gabriela S.; Domené, Esteban A.; Velasco, Manuel I.; Bedini, Paula C.; Linck, Yamila Garro; Masiero, Diana; Monti, Gustavo A.; Acosta, Rodolfo H.

doi:10.1016/j.fuel.2021.122863

Cited by 20 publications

(13 citation statements)

References 36 publications

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“…Region 2 is assigned to solid organic matter: kerogen and solid bitumen. We have previously demonstrated that the intensity of this region correlates with TOC for outcrop samples, where no moveable hydrocarbons are present . Because kerogen is a porous material that can be swollen, heptane can be present in its porous network and is also assigned to region 2.…”

Section: Resultsmentioning

confidence: 93%

“…We have previously demonstrated that the intensity of this region correlates with TOC for outcrop samples, where no moveable hydrocarbons are present. 54 Because kerogen is a porous material that can be swollen, heptane can be present in its porous network and is also assigned to region 2. Region 3 represents water in the pores space and adsorbed in clay, and finally, region 4 is assigned to moveable hydrocarbons.…”

Section: Resultsmentioning

confidence: 99%

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Quantification of Imbibed Heptane in Shale Rocks Determined by Edited T₁–T₂ Nuclear Magnetic Resonance Relaxation Experiments at High Magnetic Field

Mohammadi

Delfa²,

Velasco

et al. 2022

Energy Fuels

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Typification and quantification of organic matter and fluids in shale rocks are prime topics for the characterization and geochemical evaluation of unconventional oil reservoirs. High field 1 H nuclear magnetic resonance is a fast and reliable technique that requires a small amount of sample. The acquisition of T 1 −T 2 relaxation correlation maps provide a rich variety of information, where signals arising from solid organic matter may be clearly distinguished from that of water or hydrocarbon. However, quantification is hampered due to the finite echo times used in the multipulse sequence used to determine the T 2 distribution, where even for the shortest available echo times partial relaxation is unavoidable. In this work, we apply a variation of a sequence developed for fluid typing at low fields in conventional reservoirs to shale mudstones at a high magnetic field. The addition of a Hahn echo with variable echo time applied before the T 2 determination renders a data set from which extrapolation to time zero is more accurate than with previous methods. We applied this sequence to a sample saturated with a varying degree of heptane and compare our results with gravimetric ones. Furthermore, the evaporation kinetics show a change from a funicular to a pendular regime when the amount of heptane evaporating from inorganic pores reaches a critical level.

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Section: Resultsmentioning

confidence: 93%

Section: Resultsmentioning

confidence: 99%

Quantification of Imbibed Heptane in Shale Rocks Determined by Edited T₁–T₂ Nuclear Magnetic Resonance Relaxation Experiments at High Magnetic Field

Mohammadi

Delfa²,

Velasco

et al. 2022

Energy Fuels

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“…T1-T2 maps were acquired with the SR-FID-ECHO-CPMG sequence introduced by Silletta et al [12], a scheme that allows to probe the decay of both solid-like and liquid components of shale samples in a single measurement. In this setup, T1 was encoded with a saturation recovery (SR) sequence with delay time from 21 μs to 390 ms in 50 logarithmic steps.…”

Section: Nuclear Magnetic Resonance (Nmr)mentioning

confidence: 99%

“…Nuclear magnetic resonance (NMR) is a widely used technique to characterize the porosity framework and fluid properties of shale plays due to its noninvasive nature and the possibility of performing in-situ measurements. Recently, the application of low field NMR laboratory measurements to detect both fluid (water and hydrocarbons) and solid-like organic matter components in Vaca Muerta samples was demonstrated, making low field NMR a powerful technique to improve the petrophysical characterization of this unit [12].…”

Section: Introductionmentioning

confidence: 99%

An integrated petrophysical analysis based on NMR, organic geochemistry and mineralogy. The Vaca Muerta source rock-unconventional play at different thermal maturities

et al. 2023

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The Vaca Muerta Formation (Upper Jurassic–Lower Cretaceous) of the Neuquén Basin, Argentina is a world-class source rock and renowned as an unconventional reservoir for both oil and gas. The present study examines rotary sidewall cores representative of the oil and gas windows to analyze correlations between nuclear magnetic resonance (NMR T2 and T1-T2 maps at 2 MHz), Gas Filled Porosity (GFP), Rock-Eval programmed pyrolysis and quantitative X-ray diffraction (XRD) mineralogy. Shale samples are characterized by high present-day total organic carbon contents ranging from 3 to 7.20% (mean: 4.30%) for Well A at the oil window and, 0.72 to 11.77% (mean: 5.86%) for Well B at the gas window. The analyzed set also covers a wide compositional spectrum from carbonate-rich (> 50% of calcite and minor dolomite), mixed carbonate-siliciclastic (30 to 50% of calcite), to siliciclastic-rich (< 30% of calcite) samples. Notably, the clay fraction is dominated by interstratified illite-smectite minerals with less than 10% of expandable layers. Total porosity, calculated from Gas Filled Porosity plus NMR T2 Cumulative Distribution, is in the range of 10 to 20 porosity units. In this work we also present a new NMR sequence to detect solid-like organic matter with NMR at 2 MHz in an integrated workflow to characterize petrophysical properties of the Vaca Muerta Formation.

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“…However, it was argued that kerogen maturation would result in losing 1 H density meaning, this would enlarge the average 1 H-1 H dipolar coupling distances resulting in longer T 2 . NMR has shown its effectiveness in organic matter quantification (Silletta et al 2022), has introduced a mixed scheme that combine the tradition CPMG, that senses the long-time decay, with the fast-decaying signal acquisition during the free induction decay (FID). The method was used on several samples obtained from Muerta Formation in the Neuquen Basin, Argentina, with high success.…”

Section: Unconventional Rock Characterization Using Different Nmr Tec...mentioning

confidence: 99%

A review on the applications of nuclear magnetic resonance (NMR) in the oil and gas industry: laboratory and field-scale measurements

Elsayed

Isah

Hiba

et al. 2022

J Petrol Explor Prod Technol

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This review presents the latest update, applications, techniques of the NMR tools in both laboratory and field scales in the oil and gas upstream industry. The applications of NMR in the laboratory scale were thoroughly reviewed and summarized such as porosity, pores size distribution, permeability, saturations, capillary pressure, and wettability. NMR is an emerging tool to evaluate the improved oil recovery techniques, and it was found to be better than the current techniques used for screening, evaluation, and assessment. For example, NMR can define the recovery of oil/gas from the different pore systems in the rocks compared to other macroscopic techniques that only assess the bulk recovery. This manuscript included different applications for the NMR in enhanced oil recovery research. Also, NMR can be used to evaluate the damage potential of drilling, completion, and production fluids laboratory and field scales. Currently, NMR is used to evaluate the emulsion droplet size and its behavior in the pore space in different applications such as enhanced oil recovery, drilling, completion, etc. NMR tools in the laboratory and field scales can be used to assess the unconventional gas resources and NMR showed a very good potential for exploration and production advancement in unconventional gas fields compared to other tools. Field applications of NMR during exploration and drilling such as logging while drilling, geosteering, etc., were reviewed as well. Finally, the future and potential research directions of NMR tools were introduced which include the application of multi-dimensional NMR and the enhancement of the signal-to-noise ratio of the collected data during the logging while drilling operations.

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

Cited by 20 publications

References 36 publications

Quantification of Imbibed Heptane in Shale Rocks Determined by Edited T₁–T₂ Nuclear Magnetic Resonance Relaxation Experiments at High Magnetic Field

Quantification of Imbibed Heptane in Shale Rocks Determined by Edited T₁–T₂ Nuclear Magnetic Resonance Relaxation Experiments at High Magnetic Field

An integrated petrophysical analysis based on NMR, organic geochemistry and mineralogy. The Vaca Muerta source rock-unconventional play at different thermal maturities

A review on the applications of nuclear magnetic resonance (NMR) in the oil and gas industry: laboratory and field-scale measurements

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

Cited by 20 publications

References 36 publications

Quantification of Imbibed Heptane in Shale Rocks Determined by Edited T1–T2 Nuclear Magnetic Resonance Relaxation Experiments at High Magnetic Field

Quantification of Imbibed Heptane in Shale Rocks Determined by Edited T1–T2 Nuclear Magnetic Resonance Relaxation Experiments at High Magnetic Field

An integrated petrophysical analysis based on NMR, organic geochemistry and mineralogy. The Vaca Muerta source rock-unconventional play at different thermal maturities

A review on the applications of nuclear magnetic resonance (NMR) in the oil and gas industry: laboratory and field-scale measurements

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Product

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Quantification of Imbibed Heptane in Shale Rocks Determined by Edited T₁–T₂ Nuclear Magnetic Resonance Relaxation Experiments at High Magnetic Field

Quantification of Imbibed Heptane in Shale Rocks Determined by Edited T₁–T₂ Nuclear Magnetic Resonance Relaxation Experiments at High Magnetic Field