scholarly journals Mechanisms of liquid imbibition in Douglas-fir inferred from 1H nuclear magnetic resonance methods

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Dang Mao Nguyen ◽  
Sabine Care ◽  
Denis Courtier-Murias ◽  
Meng Zhou ◽  
Philippe Coussot
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Cell Walls ◽  
Bound Water ◽  
Free Water ◽  
Douglas Fir ◽  
Water Control ◽  
Water Imbibition ◽  
Hydraulic Network ◽  
Nuclear Magnetic

AbstractThis study aims at identifying the mechanisms of oil and water imbibition in heartwood and sapwood of Douglas-fir through a combination of original experiments with magnetic resonance imaging (MRI) and nuclear magnetic resonance (NMR) relaxation measurements for oil and free water, and deformation measurements for bound water. Experiments by weighing are performed to verify whether the imbibition process is also consistent with Washburn law. All the results are discussed taking into account the structure of wood (tubular tracheids closed at their tips, but possibly connected to each other via open pits on the side faces) and the preparation of samples. The observation of relatively fast oil flow imbibition confirms that sapwood exhibits a connected hydraulic network through which a liquid can a priori flow and climb along the structure. However, the spontaneous water imbibition is strongly damped by its very poor wetting when in contact with cell-walls only partially saturated with bound water, so that the diffusion of bound water control the uptake dynamics. However, due to preferentially closed pits, the heartwood does not exhibit a continuous hydraulic network and water essentially penetrates into wood by diffusion through the cell walls.

Water migration in poplar wood during microwave drying studied by time domain nuclear magnetic resonance (TD-NMR)

Holzforschung ◽  
2017 ◽  
Vol 71 (11) ◽  
pp. 881-887 ◽  
Author(s):  
Xinyu Li ◽  
Yulei Gao ◽  
Minghui Zhang ◽  
Ximing Wang ◽  
Xinyue Wei
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Time Domain ◽  
Bound Water ◽  
Free Water ◽  
Microwave Drying ◽  
Drying Rate ◽  
Drying Time ◽  
The Time Domain ◽  
Nuclear Magnetic

AbstractThe migration of bound water and free water has been investigated during microwave drying of wood by the time domain nuclear magnetic resonance (TD-NMR) technique. Both the heartwood (hW) and sapwood (sW) of Beijing poplar (Populus beijingensisW. Y. Hsu) and Qingpi poplar (Populus platyphyllaT. Y. Sun) were studied. The microwave drying is characterized by a fast drying rate, and there is a linear relation between moisture content (MC) and microwave drying time (t). The drying rate of free water is about 2.7 times more rapid than that of bound water. The spin-spin relaxation time (T2) revealed that most of the water was free water situated in smaller pores. The irregular T2 signal amplitudes of free water in hWs indicated that fractional water in smaller pores was transferred into bigger pores during drying.

Probing water partitioning in unsaturated weather rock using nuclear magnetic resonance

Geophysics ◽  
2021 ◽  
pp. 1-70
Author(s):  
Fan Zhang ◽  
Chi Zhang
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Pore Structure ◽  
Gaussian Function ◽  
Decomposition Analysis ◽  
Bound Water ◽  
Free Water ◽  
Critical Zone ◽  
Pore Sizes ◽  
Nuclear Magnetic

The “Rock moisture” (exchangeable water stored in weathered bedrock beneath the soil) is a key and yet overlooked component in hydrologic cycles. It can be partitioned to free water and capillary-bound water. Determining dynamic partitioning of rock moisture is crucial for conceptualizing critical zone functions and climate and hydrologic modeling. However, the quantification of rock moisture partitioning is challenging, especially in rocks with complex pore structure and weathering patterns. To quantify the dynamics of rock moisture partitioning during the drying process, laboratory nuclear magnetic resonance (NMR) measurements are performed on heterogeneous bedrock samples from a merokarst aquifer. By fitting a multi-Gaussian function, NMR T2 relaxation time spectra are auto-decomposed into multiple T2 peaks representing different pore sizes and environments. This spectral analysis enables us to track the change of position, width, and area of peaks at any given saturation stage, shedding light on water depletion rates and patterns, water residence time, and partitioning and redistribution of the water in drying rocks. Combining with mineralogic information and T2- T2 measurements, it is shown that rock moisture depletion and redistribution are closely related to the pore structures. Limestone with well-connected macropores shows a sequential water loss from large to small pores, while limestone with poorly-connected macropores simultaneously loses water from all pore sizes. The T2 peak decomposition analysis is rigorous and can be extended to field-scale to discern nuanced rock moisture partitioning in complex pore structure and to harness the rich information provided by NMR during critical zone hydrogeological investigations. Valuable insights are gained from our work towards groundwater recharge and discharge, weathering, and dry season evapotranspiration.

scholarly journals Experimental Investigation of Spontaneous Imbibition of Water into Hydrate Sediments Using Nuclear Magnetic Resonance Method

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 445 ◽  
Author(s):  
Liu Yang ◽  
Chuanqing Zhang ◽  
Jianchao Cai ◽  
Hongfeng Lu
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Research Work ◽  
Resonance Method ◽  
Fracture Network ◽  
Gas Production ◽  
Spontaneous Imbibition ◽  
Nuclear Magnetic Resonance Method ◽  
Water Imbibition ◽  
Nuclear Magnetic

Field observations show that less than one percent of dissociation water can be produced during gas hydrate production, resulting from spontaneous water imbibition into matrix pores. What’s more, the hydrate sediments are easily dispersed in water, and it is difficult to carry out spontaneous imbibition experiments. At present, there is little research work on the imbibition capacity of hydrate sediments. In this paper, a new method of water imbibition is proposed for hydrate sediments, and nuclear magnetic resonance (NMR) technique is used to monitor water migration. The results show that as the imbibition time increases, the water is gradually imbibed into matrix pores. Water imbibition can cause dramatic changes in pore structure, such as microfracture initiation, fracture network generation and skeleton dispersion. When the imbibition time exceeds a critical value, many secondary pores (new large pores and micro-fractures) start to appear. When imbibition time exceeds the dispersion time, fracture networks are generated, eventually leading to dispersion of the sediment skeleton. The imbibition curves of hydrate sediments can be divided into two linear stages, which corresponds, respectively, to water imbibition of primary pores and secondary pores. The imbibition rate of secondary pores is significantly larger than that of primary pores, indicating that the generation of new fractures can greatly accelerate the imbibition rate. Research on the characteristics of water imbibition in hydrate sediments is important for optimizing hydrate production regime and increasing natural gas production.

Nuclear Magnetic Resonance Logging While Drilling in Complex Lithology – Solution for a Glauconitic Sandstone Reservoir

2016 ◽  
Author(s):  
Ahmed Abouzaid ◽  
Holger Thern ◽  
Mohamed Said ◽  
Mohammad ElSaqqa ◽  
Mohamed Elbastawesy ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Bound Water ◽  
Total Porosity ◽  
Accessory Minerals ◽  
Formation Evaluation ◽  
Rock Quality ◽  
Logging While Drilling ◽  
Bahariya Formation ◽  
Nuclear Magnetic

ABSTRACT The evaluation of logging data in shaly sand reservoirs can be a challenging task, particularly in the presence of accessory minerals such as glauconite. Accessory minerals affect the measurements of conventional logging tools, thus, introducing large uncertainties for estimated petrophysical properties and reservoir characterization. The application of traditional Gamma Ray and Density-Neutron crossover methods can become unreliable even for the simple objective of differentiating reservoir from non-reservoir zones. This was the situation for many years in the glauconite-rich Upper Bahariya formation, Western Desert, Egypt. Formation evaluation was challenging and the results often questionable. Adding Nuclear Magnetic Resonance (NMR) Logging While Drilling (LWD) data in three wells changed the situation radically. The NMR data unambiguously indicate pay zones and simplify the interpretation for accurate porosity and fluid saturation dramatically. Key to success is NMR total porosity being unaffected by the presence of accessory minerals. NMR moveable fluid directly points to the pay zones in the reservoir, while clay-bound and capillary-bound water volumes reflect variations in rock quality and lithology. Although the NMR total porosity is lithology independent, the presence of glauconite affects the NMR T2 distribution by shifting the water T2 response to shorter T2 times. This requires an adjustment of the T2 cutoff position for separating bound water from movable hydrocarbons. A varying T2 cutoff was computed by comparing NMR bound water to resistivity-based water saturation. The calibrated T2 cutoff exhibits an increase with depth indicating a decreasing amount of glauconite with depth throughout the Upper Bahariya formation. Based on these volumetrics, an improved NMR permeability log was calculated, now accurately delineating variations in rock quality throughout the different pay zones. In addition, viscosity was estimated from the oil NMR signal. The estimated values match the expected values very well and illustrate the potential of NMR to indicate viscosity variations. Many of these results are available today already in real-time by transmitting NMR T2 distributions to surface while drilling. Besides the application for formation evaluation, the data can be used to initiate optimized side-tracking and completion decisions directly after finishing the drilling operations.

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