Visualized Experiments on Residual Oil Classification and Its Influencing Factors in Waterflooding Using Micro-Computed Tomography

Pore-scale mechanism of the waterflooding process contributes to enhanced oil recovery, which has been widely emphasized in the petroleum industry. In this paper, pore-scale waterflooding experiments are carried out on mixed-wetted natural sandstone and 3D printed sandstone using micro-computed tomography (μ-CT). The high-resolution images of oil/water distribution in different stages of waterflooding cycles are acquired. The classification of residual oil after waterflooding is conducted using the shape factor and Euler number, which represents the shape and spatial connectivity, respectively. The in situ contact angles are measured on the segmented images and the pore-scale wettability of these two samples is analyzed. Then, the effects of pore structure, micro-fracture and wettability on the distribution of the patterns of residual oil are analyzed. The results indicate that the types of isolated, cluster, network, and film (only for natural sample) are the main forms of residual oil patterns after the waterflooding process. The negative correlation between the shape factor and the Euler number of the typical oil blocks are presented. The effect of wettability and pore geometry on the morphology of the oil/water interface is quantitatively studied. The capillary pressure is the key factor for the formation of the residual oil blocks, the morphology of which is controlled by both wettability and pore geometry.

[1]  Y. Pei,et al.  Pore-scale investigation of microscopic remaining oil variation characteristics in water-wet sandstone using CT scanning , 2017 .

[2]  M. Blunt,et al.  Imaging and Measurement of Pore‐Scale Interfacial Curvature to Determine Capillary Pressure Simultaneously With Relative Permeability , 2018, Water Resources Research.

[3]  C. Pu,et al.  The visual and quantitative study of remaining oil micro-occurrence caused by spontaneous imbibition in extra-low permeability sandstone using computed tomography , 2019, Fuel.

[4]  Martin J. Blunt,et al.  Pore‐by‐pore capillary pressure measurements using X‐ray microtomography at reservoir conditions: Curvature, snap‐off, and remobilization of residual CO2 , 2014 .

[5]  Rui Song,et al.  Comparative analysis on pore‐scale permeability prediction on micro‐CT images of rock using numerical and empirical approaches , 2019, Energy Science & Engineering.

[6]  Martin J. Blunt,et al.  Multiphase Flow in Permeable Media: A Pore-Scale Perspective , 2017 .

[7]  Yiqiang Li,et al.  The application of laser confocal method in microscopic oil analysis , 2014 .

[8]  Feng Ye,et al.  Visualization study on fluid distribution and end effects in core flow experiments with low-field mri method , 2015 .

[9]  Ali Q. Raeini,et al.  Automatic measurement of contact angle in pore-space images , 2017 .

[10]  M. Blunt,et al.  Wettability in complex porous materials, the mixed-wet state, and its relationship to surface roughness , 2018, Proceedings of the National Academy of Sciences.

[11]  Farid Ahmadloo,et al.  Pore-scale two-phase filtration in imbibition process through porous media at high- and low-interfacial tension flow conditions , 2010 .

[12]  Martin J. Blunt,et al.  Pore‐scale imaging of geological carbon dioxide storage under in situ conditions , 2013 .

[13]  Jingnan Zhang,et al.  Visualization experiments on polymer-weak gel profile control and displacement by NMR technique , 2017 .

[14]  Dietmar W Hutmacher,et al.  Assessment of bone ingrowth into porous biomaterials using MICRO-CT. , 2007, Biomaterials.

[15]  Hu Yongle,et al.  X-ray MCT based numerical analysis of residual oil pore-scale characteristics under various displacing systems , 2015 .

[16]  Jean-Michel Morel,et al.  Nonlocal Image and Movie Denoising , 2008, International Journal of Computer Vision.

[17]  Amber T. Krummel,et al.  Visualizing multiphase flow and trapped fluid configurations in a model three‐dimensional porous medium , 2013, 1301.4883.

[18]  Dorthe Wildenschild,et al.  Image processing of multiphase images obtained via X‐ray microtomography: A review , 2014 .

[19]  M. Santini,et al.  X-ray computed microtomography for drop shape analysis and contact angle measurement. , 2013, Journal of colloid and interface science.

[20]  M. Blunt,et al.  Modeling Oil Recovery in Mixed-Wet Rocks: Pore-Scale Comparison Between Experiment and Simulation , 2018, Transport in Porous Media.

[21]  Tayfun Babadagli,et al.  Wettability alteration: A comprehensive review of materials/methods and testing the selected ones on heavy-oil containing oil-wet systems. , 2015, Advances in colloid and interface science.

[22]  V. Joekar‐Niasar,et al.  Effects of intermediate wettability on entry capillary pressure in angular pores. , 2016, Journal of colloid and interface science.

[23]  Dorthe Wildenschild,et al.  Defining a novel pore-body to pore-throat “Morphological Aspect Ratio” that scales with residual non-wetting phase capillary trapping in porous media , 2018, Advances in Water Resources.

[24]  Rui Song,et al.  Pore scale investigation on scaling-up micro-macro capillary number and wettability on trapping and mobilization of residual fluid. , 2019, Journal of contaminant hydrology.

[25]  B. Balcom,et al.  Visualization of Waterflooding through Unconsolidated Porous Media Using Magnetic Resonance Imaging , 2009 .

[26]  M. Blunt,et al.  Spatial Correlation of Contact Angle and Curvature in Pore‐Space Images , 2018, Water Resources Research.

[27]  C. Pu,et al.  The Visual and Quantitative Study of the Microoccurrence of Irreducible Water at the Pore and Throat System in a Low-Permeability Sandstone Reservoir by Using Microcomputerized Tomography , 2018, Geofluids.

[28]  Rex D. Thomas,et al.  Wettability Determination and Its Effect on Recovery Efficiency , 1969 .

[29]  Yang Liu,et al.  Pore-Scale Imaging of the Oil Cluster Dynamic during Drainage and Imbibition Using In Situ X-Ray Microtomography , 2018 .

[30]  A. Kovscek,et al.  Direct visualization of pore-scale fines migration and formation damage during low-salinity waterflooding , 2016 .

[31]  Jianjun Liu,et al.  Single and multiple objective optimization of a natural gas liquefaction process , 2017 .

[32]  Mukul M. Sharma,et al.  Strategies for Sizing Particles in Drilling and Completion Fluid , 2004 .

[33]  Zhenhua Rui,et al.  The injectivity variation prediction model for water flooding oilfields sustainable development , 2019 .

[34]  A. Shapiro,et al.  Mechanisms of smart waterflooding in carbonate oil reservoirs - A review , 2019, Journal of Petroleum Science and Engineering.

[35]  P. Behrenbruch,et al.  Wettability quantification - Prediction of wettability for Australian formations , 2011, IPTC 2011.

[36]  Jun Yao,et al.  Microscopic Determination of Remaining Oil Distribution in Sandstones With Different Permeability Scales Using Computed Tomography Scanning , 2019, Journal of Energy Resources Technology.

[37]  Rui Song,et al.  A new method to reconstruct structured mesh model from micro-computed tomography images of porous media and its application , 2017 .

[38]  S. Benson,et al.  Pore-scale capillary pressure analysis using multi-scale X-ray micromotography , 2017 .

[39]  M. Blunt,et al.  Fast X-Ray Micro-CT Study of the Impact of Brine Salinity on the Pore-Scale Fluid Distribution During Waterflooding , 2017 .

[40]  Chaohua Guo,et al.  Effect of pore structure on displacement efficiency and oil-cluster morphology by using micro computed tomography (μCT) technique , 2018, Fuel.

[41]  R. Juanes,et al.  Pore geometry control of apparent wetting in porous media , 2018, Scientific Reports.

[42]  M. Blunt,et al.  In situ characterization of immiscible three-phase flow at the pore scale for a water-wet carbonate rock , 2018, Advances in Water Resources.

[43]  W. B. Lindquist,et al.  3D image-based characterization of fluid displacement in a Berea core , 2007 .

[44]  Kuo Zhang,et al.  Study of the numerical simulation of tight sandstone gas molecular diffusion based on digital core technology , 2018, Petroleum Science.

[45]  Ryan T. Armstrong,et al.  Linking pore-scale interfacial curvature to column-scale capillary pressure , 2012 .

[46]  M. Blunt,et al.  In situ characterization of mixed-wettability in a reservoir rock at subsurface conditions , 2017, Scientific Reports.