Research
Near-Surface Geophysics
The focus of my current research is mainly the applications of geophysical methods (e.g., electrical resistivity and induced polarization) for understanding and monitoring near-surface geological, environmental and engineering processes.
Locating and characterizing orphaned oil and gas wells. It is estimated that more than 3 million orphaned and abandoned oil and gas wells exist in the U.S. that are leaking greenhouse gases and dangerous chemicals into the environment and thus pose both environmental and health risks to the public. Most of these wells have been out of use since early 1900s and may be missing wellheads or are rusted and covered by overgrown vegetation. Therefore, they are difficult to visibly notice and locate. Additionally, the state of their emissions is unknown. Geophysical methods can help in two ways, 1) locating the wells and characterizing their emission. In a novel approach, Saneiyan and Mansourian (2023) showed that smartphones can be used to detect the magnetic signatures of the casing of such wells from the air.
UAV Smartphone survey setup (U.S. Patent pending)
UAV Smartphone survey results at an orphaned gas well site (satellite images are from 2022). a) drone altitude ≈ 10 m AGL, b) drone altitude ≈ 15 m AGL, and c) drone altitude ≈ 20 m AGL
Prediction of soil behavior under dynamic forces (e.g. flooding, earthquake and heavy rain) by using novel methods for this purpose (e.g. complex resistivity and 3D induced polarization imaging).
Previous works have shown that it is possible to track rock and soil failure under load, however our current understanding with regard to predicting unconsolidated soil behavior in the field is very limited. In this research I aim to develop an early-warning system installed in-situ for monitoring unstable soils prone to landslides and shear failure.
Results of complex conductivity monitoring during a compression test leading to soil failure. Vertical stress (σv) and surface conductivity (σ''surf) percentage changes (at 4 and 50 Hz) versus vertical strain (εv). Remarkable similarities are seen between σv and σ''surf proving the potential of complex conductivity as non-disruptive method for monitoring soil deformation in the field.
Schematic of the experiment column undergone UCS test
Designing monitoring techniques/instruments for permanent site characterizations by installing geophysical instruments capable of real-time data reporting. One example is using electrical resistivity imaging in critical zones as a permanent monitoring tool to investigate the subsurface water transport in long-term. With recent advancements in computer programming (e.g., project ResIPy), I am confident that real-time geophysical monitoring will become the new frontier in subsurface monitoring.
Left: Microbial induced carbonate precipitation (MICP) treatment area at the IFRC site, Rifle, CO. Right: 3D model of the progression of MICP in subsurface at the IFRC site from the beginning of the field study to the end, based on in-situ time-domain induced polarization (TDIP) geophysical imaging.
The cutoff value for the phase angle anomaly (blue volume) is 4.5 < -φ < 6 mrad.
Green vertical lines: MICP treatment injection wells, red vertical lines: withdrawal wells. Saneiyan et al. (2019)
3D-ERI tracer studies on Tussey Mountain at the Shavers Watershed at Shale Hills CZO, PA. A potassium bromide solution was allowed to percolate in shallow trenches dug directly upslope (top images) of the electrical resistivity imaging (ERI) grid (bottom left). ERI measurements were collected from a 3D surface array consisting of a 12 by 4 grid of electrodes spaced 1 m apart. Our image (bottom right) revealed initial rapid vertical movement downward of the tracer followed by a slower horizontal movement along a boundary layer, in support of previous shallow interflow hypotheses. We also find that the spatial extent and by extension mass moments vary depending on the hillslope. Using 3D-ERI to image tracer migration provided a better understanding of the dynamic flow architecture at the site.
Basic science research (laboratory/pilot study) for understanding microscopic properties of soils/rocks using advanced geophysical techniques (e.g. spectral induced polarization) to improve our understanding of micro-scale hydrogeological processes remotely/indirectly.
Artificial soil mixture before (above left) and after (above right) 384 hrs of MICP treatment. Unconsolidated artificial soil mixture turned into consolidated state.
Imaginary conductivity (σ'') response (diagram at right) from low to high (160 mHz, 5, 40 and 500 Hz) shows a clear pattern of carbonate (mainly calcite in here) precipitation. From fine grain to coagulated precipitation (conceptual model below).
Conceptual model of calcite precipitation inside the MICP treated soil column. Stage 1: no precipitation (background). Stage 2: precipitation of fine grain calcite minerals. Stage 3: formation of biofilm within the pore space along with calcite mineral coagulation and layering. Stage 4: steady state, mineral layering and pore clogging is maintained (blue dashed line represents the presumed signal trend if the experiment continued).
