2D micromodel studies of pore-throat clogging by pure fine-grained sediments and natural sediments from NGHP-02, offshore India

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What does this data set describe?

Title:
2D micromodel studies of pore-throat clogging by pure fine-grained sediments and natural sediments from NGHP-02, offshore India
Abstract:
Fine-grained sediments, or “fines,” are nearly ubiquitous in natural sediments, even in the predominantly coarse-grained sediments that host gas hydrates. Fines within these sandy sediments can be mobilized and subsequently clog flow pathways while methane is being extracted from gas hydrate as an energy resource. Using two-dimensional (2D) micromodels to test the conditions in which clogging occurs provides insights for choosing production operation parameters that optimize methane recovery in the field. During methane extraction, several processes can alter the mobility and clogging potential of fines: (1) fluid flow as the formation is depressurized to release methane from gas hydrate, (2) shifting pore-fluid chemistry as pore-fluid brine freshens as a result of pure water released from dissociating gas hydrate, and (3) the migration of gas/water interfaces, which are created as gas evolves from dissociating gas hydrate. In this study, 2D micromodel experiments were conducted on a selection of pure fines, natural sediments, pore-fluids, and micromodel pore-throat sizes to evaluate fines migration and changes in clogging behavior resulting from methane gas production and pore-water freshening during hydrate dissociation. Additionally, tests were run with and without an invading gas phase (carbon dioxide) to test the importance of a moving meniscus on fines mobility and clogging. The endmember fine particles chosen for this research included silica silt, mica, calcium carbonate, diatoms, kaolinite, illite, and bentonite (primarily made of montmorillonite). The pore fluids included deionized water, sodium chloride brine (2 molar concentration), and carbon dioxide gas. The microfluidic pore models, used as porous media analogs, were fabricated with pore-throat widths of 20, 40, 60 and 100 micrometers to cover the range of anticipated pore throat sizes sampled during NGHP-02. This dataset provides a clogging diagram showing how grain size, fines concentration, pore fluid chemistry and mobile interfaces define the clogging behavior of the pure fines. This fundamental properties diagram helps interpret the clogging behavior of three natural samples also tested for this dataset. The natural samples were collected during NGHP-02. This research shows that in addition to the expected dependence of clogging on the ratio of particle-to-pore-throat size, pore-fluid chemistry is also an important factor because the interaction between a particular type of fine and pore fluid influences that fine’s capacity to cluster, clump together, and thereby increase the effective particle size relative to the pore-throat width. The presence of a moving gas/fluid meniscus increases the clogging potential regardless of fine type because the advancing meniscus tends to gather and concentrate the fines.
Supplemental_Information:
In addition to funding from the U.S. Geological Survey’'s Gas Hydrate Project, this work is sponsored in part by the Department of Energy, both through an interagency agreement (DE-FE0026166) and a grant awarded to Louisiana State University (DE-FE0028966). More information about the project can be found at: https://www.netl.doe.gov/research/oil-and-gas/project-summaries/methane-hydrate/fe0028966-lsu-fe0026166-usgs
  1. How might this data set be cited?
    Cao, Shuang C., Jang, Junbong, Jung, Jongwon, Waite, William F., Collett, Timothy S., and Kumar, Pushpendra, 2018, 2D micromodel studies of pore-throat clogging by pure fine-grained sediments and natural sediments from NGHP-02, offshore India: data release DOI:10.5066/P9PZ5M7E, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    Suggested citation: Cao, S.C., Jang, J., Jung, J., Waite, W.F., Collett, T.S., and Kumar, P., 2018, 2D micromodel studies of pore-throat clogging by pure fine-grained sediments and natural sediments from NGHP-02, offshore India: U.S. Geological Survey data release, https://doi.org/10.5066/P9PZ5M7E.
    This dataset supports the following publication:
    Cao, S.C., Jang, J., Jung, J., Waite, W.F., Collett, T.S., and Kumar, P., 2018. 2D micromodel study of clogging behavior of fine-grained particles associated with gas hydrate production in NGHP-02 gas hydrate reservoir sediments: Marine and Petroleum Geology, https://doi.org/10.1016/j.marpetgeo.2018.09.010.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: 82.9421
    East_Bounding_Coordinate: 84.197675
    North_Bounding_Coordinate: 17.438455
    South_Bounding_Coordinate: 16.5691
  3. What does it look like?
    https://www.sciencebase.gov/file/get/5b0da47ce4b0c39c934b0775?name=Fines_Micromodel_BrowseGraphic.png (PNG)
    Image showing bentonite clusters clogging pore throats in a 2D glass micromodel
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 22-May-2015
    Currentness_Reference:
    These are the dates the NGHP-02 specimens were collected from Sites NGHP-02-16 (20150522) and NGHP-02-09 (20150618). Data were also collected for pure, endmember sediment types that were purchased rather than collected.
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Point data set. It contains the following vector data types (SDTS terminology):
      • Point (43)
    2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.0000001. Longitudes are given to the nearest 0.0000001. Latitude and longitude values are specified in decimal degrees. The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.
      Vertical_Coordinate_System_Definition:
      Depth_System_Definition:
      Depth_Datum_Name: Meters below sea floor
      Depth_Resolution: 1
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Attribute values
  7. How does the data set describe geographic features?
    2D_Micromodel_Fines_Data
    Minimum fines concentration (by mass) that causes clogging of fluid flow through 2D micromodels as a function of pore throat size, sediment type, pore fluid chemistry, and pore fluid phase. (Source: Louisiana State University)
    Sediment
    Sediment: Type of sediment used in the micromodel test. Sediment names followed by (g/ml concentration) have concentrations listed as percent by fluid volume rather than the typical percent by mass used for the other sediments. (Source: Louisiana State University) Character set (text).
    Latitude (decimal degrees)
    Lat: Latitude decimal degrees north for specimens collected during NGHP-02. A value of -99999 indicates a purchased specimen. (Source: Shipboard science party, D/V Chikyu)
    Range of values
    Minimum:16.5691
    Maximum:17.438455
    Longitude (decimal degrees)
    Lon: Longitude decimal degrees east for specimens collected during NGHP-02. A value of -99999 indicates a purchased specimen. (Source: Shipboard science party, D/V Chikyu)
    Range of values
    Minimum:82.94205
    Maximum:84.197675
    Average Depth using CSF-B convention (mbsf)
    Depth: Depth of NGHP-02 samples in meters below the sea floor (mbsf), using the CSF-B convention in which gas expansion gaps, if present at the time of core recovery, have been removed. A value of -99999 indicates a purchased sample. (Source: Shipboard science party, D/V Chikyu)
    Range of values
    Minimum:250.975
    Maximum:278.015
    Units:meters
    Electrical Sensitivity (unitless)
    Sensitivity: Electrical sensitivity of the endmember fine sediment used in the micromodel test, as measured in a companion study (Jang, J., Cao, S.C, Stern, L.A., Jung, J., and Waite, W.F., 2018, Impact of pore-fluid chemistry on fine-grained sediment fabric and compressibility: Journal of Geophysical Research, https://doi.org/10.1029/2018JB015872). The NGHP-02 sample sizes were too small for the electrical sensitivity measurement, so entries for these samples are given as -99999. (Source: U.S. Geological Survey)
    Range of values
    Minimum:0.37
    Maximum:1.22
    Units:unitless
    d50 (micrometers)
    d50: Mean grain size of the endmember fine (Source: U.S. Geological Survey)
    Range of values
    Minimum:2
    Maximum:59
    Units:micrometers
    Pore Throat (micrometers)
    Throat: Width of each pore throat between circular "grains" in the 2D micromodel (Source: Louisiana State University)
    Range of values
    Minimum:20
    Maximum:100
    Units:micrometers
    Grain Size/Pore Throat Ratio (unitless)
    SizeRatio: Grain size divided by pore throat size (Source: Louisiana State University)
    Range of values
    Minimum:0.02
    Maximum:2.95
    Units:unitless
    Clogging concentration in bulk deionized water (percent)
    Clog_water: Minimum concentration of fines (mass of fines per mass of deionized water) required to cause a clog in the given micromodel filled with deionized water. Note: this is mass of fines per volume of deionized water for specimen names that include (g/ml concentration). (Source: Louisiana State University)
    Range of values
    Minimum:less than 0.1
    Maximum:greater than 10
    Units:percent
    Clogging concentration in water with CO2 flushing (percent)
    Clog_water_CO2: Minimum concentration of fines (mass of fines per mass of deionized water) required to cause a clog in the given micromodel when a carbon dioxide (CO2) meniscus passes through the deionized water. Note: this is mass of fines per volume of deionized water for specimen names that include (g/ml concentration). (Source: Louisiana State University)
    Range of values
    Minimum:less than 0.1
    Maximum:greater than 10
    Units:percent
    Clogging concentration in 2M bulk brine (percent)
    Clog_brine: Minimum concentration of fines (mass of fines per mass of 2-molar brine) required to cause a clog in the given micromodel filled with 2-molar brine. Note: this is mass of fines per volume of deionized water for specimen names that include (g/ml concentration). (Source: Louisiana State University)
    Range of values
    Minimum:less than 0.1
    Maximum:greater than 5
    Units:percent
    Clogging concentration in 2M brine with CO2 flushing (percent)
    Clog_brine_CO2: Minimum concentration of fines (mass of fines per mass of 2-molar brine) required to cause a clog in the given micromodel when a carbon dioxide (CO2) meniscus passes through the 2-molar brine. Note: this is mass of fines per volume of deionized water for specimen names that include (g/ml concentration). (Source: Louisiana State University)
    Range of values
    Minimum:less than 0.1
    Maximum:greater than 5
    Units:percent
    Entity_and_Attribute_Overview:
    These data are available in a Microsoft Excel XLSX as well as a CSV format. The first two rows in the XLSX file are header rows, where the second row is an abbreviated column label intended for software packages that are unable to cope with longer labels available in the first row of the XLSX file. The first part of the attribute definition (before the colon) indicates the abbreviated column label. The first row of the CSV file is a header line and is the same as the abbreviated column label on the second row of the XLSX file.
    Entity_and_Attribute_Detail_Citation: U.S. Geological Survey

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Shuang C. Cao
    • Junbong Jang
    • Jongwon Jung
    • William F. Waite
    • Timothy S. Collett
    • Pushpendra Kumar
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    U.S. Geological Survey
    Attn: William F. Waite
    Research Geophysicist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x2346 (voice)
    508-457-2310 (FAX)
    wwaite@usgs.gov

Why was the data set created?

This dataset provides a comprehensive relationship between the minimum concentration of fines (concentration = mass of fines divided by the mass of fluid) required to clog two-dimensional micromodel pore throats of various sizes. The clogging dependence is captured in terms of the sediment type, the ratio of the mean particle size to the pore throat size, the pore fluid chemistry (fresh water or brine) and whether or not there is a gas/water meniscus. Each of these parameters provides information required for estimating the clogging potential of fines in natural settings, such as in sediments where gas hydrates are being destabilized to extract the methane as an energy resource.

How was the data set created?

  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
    Date: 31-Jul-2015 (process 1 of 8)
    Deployment sample collection: All specimens were collected from the working half of split cores collected from 20150428 – 20150731. Specimens were stored in heat-sealed plastic specimen bags and refrigerated during the expedition. Depth below sea floor was determined from centimeter scales running alongside the cores during processing, then tied to the continuous downhole depth log using both the IODP standard depth terminologies, which are each based on drilling records of the drill pipe length: CSF-B (total depth from sea floor to target sediment, after all gas expansion gaps have been removed). The sea floor depth reference (mudline) was determined from a combination of noting when the drill string contacted the sea floor and increased the measured weight-on-bit, and visual verification of the drill bit position using an ROV. Person who carried out this activity:
    U.S. Geological Survey
    Attn: William F. Waite
    Research Geophysicist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x2346 (voice)
    wwaite@usgs.gov
    Date: 08-Oct-2017 (process 2 of 8)
    Laboratory sampling: After the shipboard specimen collection, the specimens were shipped in coolers with cold packs to the Woods Hole Coastal and Marine Science Center (WHCMSC), where they were subsampled for micromodel testing. Specimens of ~20 grams were sealed in plastic specimen bags and shipped to Louisiana State University for analysis. Person who carried out this activity:
    U.S. Geological Survey
    Attn: William F. Waite
    Research Geophysicist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x2346 (voice)
    wwaite@usgs.gov
    Date: 2017 (process 3 of 8)
    2D Micromodel information: The microfluidic pore models were fabricated at Louisiana State University using standard photolithography followed by soft lithography. The microfluidic pore model was made of polydimethylsiloxane (PDMS) bonded to a glass slide. Each PDMS plate consisted of a homogeneous pore network pattern to form a two-dimensional and two-symmetry pore network. The homogeneous two-dimensional pore-network had a patterned area of 2 cm × 1 cm, consisting of different circular “grain” sizes to simulate different pore throat sizes (see browse graphic). The pore throat height for each microfluidic channel was 100 micrometers, and the pore throat width for each microfluidic pore model was chosen to be either 20 micrometers, 40 micrometers, 60 micrometers, or 100 micrometers. The microfluidic pore models were cleaned between fabrication and experimental use by injecting 5 ml of reagent-grade ethanol (ACS reagent grade; Mallinckrodt Baker) followed by 30 ml of deionized water. The slides were then dried at room temperature (25 ± 1 degrees C) for 72 hours. After cleaning, the model was loaded into the experimental system. All components including the valves, filter, transparent tubing, pressure transducer (Omegadyne INC), and pressure regulator (Swagelok INC) were connected to the micromodel. Person who carried out this activity:
    Louisiana State University, Department of Civil and Environmental Engineering
    Attn: Shuang C. Cao
    Civil Engineer
    3277 Patrick F. Taylor Hall
    Baton Rouge, Louisiana
    USA

    225-578-8442 (voice)
    225-578-4945 (FAX)
    scao6@lsu.edu
    Date: 2017 (process 4 of 8)
    Specimen preparation: natural specimens from two locations in the Indian Ocean were tested during this study. From Site NGHP-02-09, the bulk sediment contained coarse-grained material. This study is interested in the clogging behavior of fines, so the bulk sediment was sieved prior to processing in the micromodel. Only sediment passing a 75 μm sieve were used in this study. From Site NGHP-02-16, the bulk sediment did not contain particles exceeding 100 micrometers, so the bulk sediment was tested as is. To facilitate the comparison with the NGHP-02-09 sediment, additional NGHP-02-16 material was sieved through the 75 micrometer sieve used for NGHP-02-09 prior to processing in the micromodel. Person who carried out this activity:
    Louisiana State University, Department of Civil and Environmental Engineering
    Attn: Shuang C. Cao
    Civil Engineer
    3277 Patrick F. Taylor Hall
    Baton Rouge, Louisiana
    USA

    225-578-8442 (voice)
    225-578-4945 (FAX)
    scao6@lsu.edu
    Date: 2017 (process 5 of 8)
    Experimental Set-up: The 2D micromodel pore model was placed horizontally on the microscope (Olympus IX51-LWD 4X/0.1) to provide a map-view of the 2D micromodel. The micromodel was connected to a syringe that was controlled with a precision syringe pump (NE-1010; Kats Scientific). The other port of the 2D micromodel was connected to another syringe pump (Teledyne ISCO) that was used to inject gas (carbon dioxide, CO2) into the micromodel. A commercial CO2 cylinder (99.99 percent; Airgas) was connected to the ISCO pump. CO2 pressure was maintained at 10 ± 1 kPa by a pressure regulator and the ISCO pump at room temperature (25 ± 1 degrees C) Person who carried out this activity:
    Louisiana State University, Department of Civil and Environmental Engineering
    Attn: Shuang C. Cao
    Civil Engineer
    3277 Patrick F. Taylor Hall
    Baton Rouge, Louisiana
    USA

    225-578-8442 (voice)
    225-578-4945 (FAX)
    scao6@lsu.edu
    Date: 2017 (process 6 of 8)
    Injection and withdrawal of the pore fluid containing fine particles: The injection fluids (deionized water or 2-molar brine) were mixed with fine particles (0.1~10 percent fine particle concentration by weight) of a given endmember sediment, and mixed in a syringe for injection into the micromodel. The syringe was connected to the micromodel inlet tube. The microfluidic model was initially saturated by injecting fluid with fine particle suspension of fixed concentration (0.1 percent, 0.5 percent, 1 percent, 2 percent, 5 percent, or 10 percent fines by mass) by hand. The syringe was then loaded onto the precision syringe pump (NE-1010; Kats Scientific) that performed a 50 microliter/minute fluid withdrawal. During this withdrawal, the micromodel was invaded by the CO2 gas, allowing a gas/water interface to move through the distribution of fines that had been injected into the model. As a check on using this mass concentration approach, a subset of the tests were re-run for silica and bentonite in which the fines suspensions were generated with volume concentrations (milligrams fines/milliliters of fluid) rather than mass concentrations (grams of fines/grams of fluid). Volume concentrations were chosen to match mass concentrations (1, 2, 5, 10, 50 milligrams silica/milliliters fluid). Person who carried out this activity:
    Louisiana State University, Department of Civil and Environmental Engineering
    Attn: Shuang C. Cao
    Civil Engineer
    3277 Patrick F. Taylor Hall
    Baton Rouge, Louisiana
    USA

    225-578-8442 (voice)
    225-578-4945 (FAX)
    scao6@lsu.edu
    Date: 2017 (process 7 of 8)
    Imaging the fines distribution in the micromodel during injection and fluid withdrawal: Digital images and video clips of the map view (top-down view) were captured during and after the experiment using the microscope image capturing capacity (Olympus IX51-LWD 4X/0.1). The migration and clogging of fines in the micromodel is analyzed using the available optical images and videos to isolate clogs. A clog is defined as a black mass spanning a pore throat in what begins as an optically clear micromodel. The minimum clogging concentration stored in the micromodel data spreadsheet is given as the lowest fines concentration for which the micromodel shows evidence of a pore-throat clog. Person who carried out this activity:
    Louisiana State University, Department of Civil and Environmental Engineering
    Attn: Shuang C. Cao
    Civil Engineer
    3277 Patrick F. Taylor Hall
    Baton Rouge, Louisiana
    USA

    225-578-8442 (voice)
    225-578-4945 (FAX)
    scao6@lsu.edu
    Date: 2017 (process 8 of 8)
    Data archiving: Microsoft Excel version 15.33 was used to consolidate all data in a spreadsheet. Measured interface heights and elapsed times were arranged by sediment and pore fluid type. Results were then exported to a comma-separated values (csv) file format. Person who carried out this activity:
    U.S. Geological Survey
    Attn: William F. Waite
    Research Geophysicist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x2346 (voice)
    508-457-2310 (FAX)
    wwaite@usgs.gov
  3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
    Horizontal position was determined by GPS satellite data, which provided guidance information for the dynamic positioning system (DPS) utilized by the D/V Chikyu. The DPS also utilizes inputs from tidal, wind and wave data to control six azimuthal thrusters beneath the ship’s hull. The thrusters are capable of 360 degree adjustment. Given the DPS capabilities, borehole locations for the D/V Chikyu are considered to be accurate to a radius of 15 meters. Details are provided in: Chikyu Hakken – Earth Discovery, Volume 1, Spring 2005, published by JAMSTEC’s Center for Deep Earth Exploration: https://www.jamstec.go.jp/chikyu/e/magazine/backnum/pdf/hk_01_e.pdf
  3. How accurate are the heights or depths?
    Coring depth measurements used on the D/V Chikyu during NGHP-02 followed standard International Ocean Drilling Program (IODP) protocols. Assessment of these protocols by IODP had determined the vertical position accuracy is on the order of centimeters to meters. Additional information about the depth conventions and accuracy are on pages 8 and 9 of the IODP report “IODP Depth Scales Terminology”: http://www.iodp.org/policies-and-guidelines/142-iodp-depth-scales-terminology-april-2011/file. Purchased specimens have a value of -99999 for location values. Depth resolution ranges from 0.01 to 1 meter.
  4. Where are the gaps in the data? What is missing?
    The minimum clogging concentrations were found for each of the endmember fines and all three NGHP-02 specimens, all four pore-throat sizes, both bulk pore-fluid chemistries, and for the moving meniscus case in each of the pore-fluid chemistries. There are no empty cells in the clogging concentration values because the complete array of test conditions was investigated. Values of -99999 are included for pure fine specimen latitudes, longitudes and depth because they were purchased rather than collected in the field. Values of -99999 are included for the electrical sensitivity of the NGHP-02 sediments because there was not enough sediment material available to measure electrical sensitivity.
  5. How consistent are the relationships among the observations, including topology?
    The 2D glass micromodels fabricated for this experiment had consistent pore-throat geometries and the fluid injection rate was constant throughout the study, the deionized water and CO2 sources were unchanged during the testing, and the molar strength for each brine test was held constant. The "environmental" conditions are therefore comparable between tests. This consistency allows logical conclusions to be drawn regarding dependencies observed on geometric factors, such as the pore throat size (relative to the particle size), and on chemical factors, such as the dependence of the clogging concentration on the pore fluid chemistry. Differences in clogging behavior between endmember fines can also be attributed to the impact of a gas/water interface because the flow rates in all cases was held constant.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints: None.
Use_Constraints:
Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the Louisiana State University as the originator of the dataset.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey - ScienceBase
    Denver Federal Center, Building 810, Mail Stop 302
    Denver, CO

    1-888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set? The dataset includes the following files: Endmember_Fines_Micromodel_Data.xlsx (data in an Excel spreadsheet), Endmember_Fines_Micromodel_Data.csv (same data in a comma-separated text file), Endmember_Fines_Micromodel_BrowseGraphic.png (browse graphic), and FGDC CSDGM metadata in XML format.
  3. What legal disclaimers am I supposed to read?
    Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
  4. How can I download or order the data?
  5. What hardware or software do I need in order to use the data set?
    If the zip file download option was used, the user must have software capable of uncompressing the zip file and reading the data formats.

Who wrote the metadata?

Dates:
Last modified: 29-Jan-2019
Metadata author:
U.S. Geological Survey
Attn: William F. Waite
Geophysicist
384 Woods Hole Rd.
Woods Hole, MA

508-548-8700 x2346 (voice)
508-457-2310 (FAX)
wwaite@usgs.gov
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

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