scholarly journals Resistivity and induced polarization monitoring of biogas combined with microbial ecology at a brownfield site

2015 ◽  
Vol 3 (4) ◽  
pp. SAB43-SAB56 ◽  
Author(s):  
Carlos A. Mendonça ◽  
Rory Doherty ◽  
Nathan D. Amaral ◽  
Blathnaid McPolin ◽  
Michael J. Larkin ◽  
...  
Keyword(s):  
Water Saturation ◽  
Good Practice ◽  
Geophysical Methods ◽  
Ground Surface ◽  
Suspended Sediments ◽  
Induced Polarization ◽  
Gas Content ◽  
Archie’S Law ◽  
Monitoring Wells ◽  
Brownfield Site

The accumulation of biogenic greenhouse gases (methane, carbon dioxide) in organic sediments is an important factor in the redevelopment and risk management of many brownfield sites. Good practice with brownfield site characterization requires the identification of free-gas phases and pathways that allow its migration and release at the ground surface. Gas pockets trapped in the subsurface have contrasting properties with the surrounding porous media that favor their detection using geophysical methods. We have developed a case study in which pockets of gas were intercepted with multilevel monitoring wells, and their lateral continuity was monitored over time using resistivity. We have developed a novel interpretation procedure based on Archie’s law to evaluate changes in water and gas content with respect to a mean background medium. We have used induced polarization data to account for errors in applying Archie’s law due to the contribution of surface conductivity effects. Mosaics defined by changes in water saturation allowed the recognition of gas migration and groundwater infiltration routes and the association of gas and groundwater fluxes. The inference on flux patterns was analyzed by taking into account pressure measurements in trapped gas reservoirs and by metagenomic analysis of the microbiological content, which was retrieved from suspended sediments in groundwater sampled in multilevel monitoring wells. A conceptual model combining physical and microbiological subsurface processes suggested that biogas trapped at depth may have the ability to quickly travel to the surface.

Combining geophysical methods to estimate the spatial distribution of soils affected by water saturation

2004 ◽  
Vol 336 (6) ◽  
pp. 553-560 ◽  
Author(s):  
Vincent Chaplot ◽  
Christian Walter ◽  
Pierre Curmi ◽  
Alain Hollier-Larousse ◽  
Henri Robain
Keyword(s):  
Spatial Distribution ◽  
Water Saturation ◽  
Geophysical Methods

scholarly journals Role of multiple reflections in the formationof wave field in the cretaceous successions of the Middli Kura depression in Azerbaijan

2021 ◽  
Vol 43 (3) ◽  
pp. 123-134
Author(s):  
T. R. Akhmedov ◽  
T. Kh. Niyazov
Keyword(s):  
Wave Field ◽  
Upper Cretaceous ◽  
Oil And Gas ◽  
Geophysical Methods ◽  
Geological Structure ◽  
Gas Content ◽  
Seismic Exploration ◽  
Time Interval ◽  
Multiple Reflections ◽  
Seismic Sections

The article is devoted to the elucidation of the nature of the wave field recorded below the supporting-dominant seismic horizon «P» in the Middle Kura depression of Azerbaijan. A brief overview of the work carried out here is given; it is indicated that some geologists and geophysicists of our country, in our opinion, mistakenly assume that the observed wave field below the specified horizon is formed mainly by multiple reflections. Since the introduction of the common depth point method into the practice of seismic exploration, individual areas of the Middle Kura depression in Azerbaijan, including the Yevlakh-Agjabedi trough, have been repeatedly studied with varying degrees of frequency tracking. On the basis of this, a fairly large number of promising structures have been identified and mapped. But the structure of the Mesozoic, in particular the deposits of the Upper Cretaceous, still remains insufficiently studied. The study of the geological structure of the Mesozoic sediments, which are considered promising in terms of oil and gas content, is an urgent geological task; exploration work was carried out in the studied areas of the Middle Kura depression using a complex of geophysical methods at the modern technical and methodological level and new results were obtained. The constructed seismic sections show a dynamically pronounced and well-traceable seismic horizon corresponding to the Mesozoic surface and located deeper than it, relatively weak, short, discontinuous reflective boundaries that characterize the structure within the Mesozoic deposits. The studies carried out on the basis of modeling and velocity analysis made it possible to prove that the wave field in the time interval corresponding to the Mesozoic deposits owes its origin to intermittent single reflections from volcanic-carbonate deposits of the Upper Cretaceous age.

Delineation of Sedimentary Facies and Groundwater-Sea Water Disposition in an Intertidal Zone of the Bay of Bengal using GPR and VES

2018 ◽  
Vol 23 (2) ◽  
pp. 235-249
Author(s):  
Mrinal Kanti Layek ◽  
Palash Debnath ◽  
Probal Sengupta ◽  
Abhijit Mukherjee
Keyword(s):  
Bay Of Bengal ◽  
Sea Water ◽  
Water Saturation ◽  
Water Discharge ◽  
Ground Surface ◽  
Sedimentary Facies ◽  
Intertidal Flat ◽  
Sediment Layer ◽  
Fresh Groundwater ◽  
Water Saturated

A combination of geophysical study including ground penetrating radar (GPR) and vertical electrical sounding (VES) was done to identify different shallow-subsurface depositional features in an intertidal coast of the eastern parts of India, adjoining the Bay of Bengal (BoB) (Chandipur, Odisha state). The study was aimed to understand the variation of sedimentary depositional sequences, prograding to the ocean from land, as well as towards the confluence of a river channel with the BoB. Six VES points and 85 GPR traverses were taken in the intertidal flat. The data were calibrated with sedimentary sequences retrieved from simultaneously drilled boreholes in four locations. Resistivity data clearly demonstrate the subsurface sediment layer boundaries with water saturation variability, up to 156 m below ground surface (bgs). The data suggest thickening of brackish water saturated clay layers towards the southwestern part. GPR data were capable of resolving the geometry of intertidal dunes, buried palaeo-channels, erosional surface, water table, eolian deposit of sand, and washover delta depositional features which are all present in this study area. Several erosional surfaces, related to sedimentary processes, e.g., delta overwash processes, were clearly demarcated. The study also successfully identified and visualized the saline-fresh groundwater interfaces and submarine ground water discharge (SGD) zones. Consequently, based on these data, a conceptual model of the depositional and erosional history of the sedimentation of the area, as well as the coastal hydrogeological disposition, was conceived.

scholarly journals Response, Remediation and Risk Management of a Crude Oil Pipeline Spill

1998 ◽  
Author(s):  
J. T. Doupe ◽  
W. R. Livingstone
Keyword(s):  
Crude Oil ◽  
Action Plan ◽  
Human Health Risk ◽  
Ground Surface ◽  
Flood Plain ◽  
Ecological Impacts ◽  
Monitoring Wells ◽  
Oil Pipeline ◽  
Subgrade Soils ◽  
Major River

In December 1995, an oil spill was discovered along a section of pipeline located near the bank of a major river, less than 1 km upstream of the water supply intake of a southern Alberta community. The spill, which involved light crude oil, was observed at ground surface over an area of approximately 3 000 m2 at the top of the river slope and had also migrated downslope through the subgrade soils and along the groundwater table toward the river. The initial emergency response activities consisted of removing and disposing of oil-stained vegetation and snow, and the containment and recovery of free oil pooled on ground surface. Subsequent subsurface assessments involved the drilling of test holes and boreholes, and installation of groundwater monitoring/recovery wells. Based on the results of these assessments, a remedial action plan was developed. As part of this plan, some of the impacted soils were excavated and placed in lined treatment cells for bioremediation. The limits of the excavation were based on field screening measurements and on soil clean-up criteria developed through an assessment of the human health risk and ecological impacts. Investigations conducted at the site also indicated that phase-separated crude oil had migrated further downslope and had accumulated at the water table within the flood plain sediments adjacent to the river. Therefore, remediation systems were installed to recover the oil, recover and treat the impacted groundwater, and prevent further migration of the impacted groundwater and oil toward the river. Impacted groundwater recovered from the flood plain deposits was treated onsite and was then injected back into the flood plain deposits via an infiltration gallery. The performance of the pumping and remediation systems was monitored regularly and water samples were recovered from the treatment system, selected monitoring wells and the river. Based on the results of these analyses, the quality of local groundwater steadily improved and the zone of impacted water was effectively contained.

GEOPHYSICAL ACTIVITY IN 1967 APPLIED TO MINING EXPLORATION

Geophysics ◽  
1968 ◽  
Vol 33 (6) ◽  
pp. 903-910 ◽  
Author(s):  
Peter J. Hood ◽  
William C. Kellogg
Keyword(s):  
Average Cost ◽  
World Wide ◽  
Geophysical Methods ◽  
Induced Polarization ◽  
Mining Companies ◽  
Electromagnetic Methods ◽  
Polarization Technique ◽  
Mining Exploration

Data on world‐wide geophysical activity in mining exploration programs is collected annually by the SEG Geophysical Activity Committee as part of a continuing service to the industry. The data is obtained by sending out questionnaires to all organizations which are known to be carrying out mining geophysical work; the organizations canvassed include mining companies, contractors, government departments and universities. The questionnaire is divided into three sections, namely ground methods, airborne methods, and research. The data compiled from the questionnaires shows that world‐wide utilization of mining geophysical methods reached a new high in 1967 with total expenditures of U.S. $32,323,240. This was divided as follows: ground methods—$18,106,785; airborne methods—$10,123,405; and research $4,093,050. For the ground methods, most money was spent on the induced‐polarization technique ($5,681,780); electromagnetic methods were second in reported expenditure ($2,010,900). Total reported geophysical line‐mileage flown was 1,275,072 line‐miles, with aeromagnetic surveying being the most popular airborne method. Total amount spent on aeromagnetic surveys was $5,832,564 for 895,420 line‐miles. This gives an average cost for aeromagnetic surveys of $6.50 per line‐mile.

A GEOPHYSICAL CASE HISTORY OF THE LAKESHORE ORE BODY

Geophysics ◽  
1971 ◽  
Vol 36 (6) ◽  
pp. 1232-1249 ◽  
Author(s):  
Philip G. Hallof ◽  
Emil Winniski
Keyword(s):  
Direct Detection ◽  
El Paso ◽  
Geophysical Methods ◽  
Field Measurements ◽  
Induced Polarization ◽  
Copper Ore ◽  
Ore Body ◽  
Ore Mineralization ◽  
History Of ◽  
Geophysical Technique

The Lakeshore ore body is in Pinal County, Arizona about 30 miles south of Casa Grande. In February, 1969 when the latest figures were published, the ore reserves were reported at 241 million tons of disseminated sulfide ore (0.7 percent copper) and 24 million tons of concentrated metallic ore (1.69 percent copper). Sulfide copper ore was first intersected in July, 1967 in Hole P‐3. The magnetite‐pyrite‐chalco‐pyrite mineralization occurred in a banded tactite at a depth of 1147 ft. Hole P‐3 was the fourth of several holes that were drilled to determine the source of an induced polarization anomaly that had been outlined, at depth, to the west of the old Lakeshore pit. The successful conclusion of this exploration program by El Paso Natural Gas Company is an excellent example of an integrated exploration approach. The application of regional geological planning, geophysical methods, and detailed geological reasoning resulted in the discovery of a major copper ore body. Due to the depth of the ore zone and the disseminated character of most of the ore, the only geophysical technique that was useful in the direct detection of the ore mineralization was the induced polarization method. Field measurements were made sporadically between August, 1966 and July, 1968. Variable‐frequency induced‐polarization measurements, made using the dipole‐dipole electrode configuration and electrode intervals from 300 ft to 1000 ft, successfully indicated the presence of the metallic mineralization at depth and gave some indication of its extent. Comparisons of the induced polarization data and the appropriate geological sections give information concerning the usefulness of the method.

Two effective methods for calculating water saturations in shale-gas reservoirs

Geophysics ◽  
2017 ◽  
Vol 82 (3) ◽  
pp. D187-D197 ◽  
Author(s):  
Jingling Xu ◽  
Lei Xu ◽  
Yuxing Qin
Keyword(s):  
Shale Gas ◽  
Water Saturation ◽  
Critical Issue ◽  
Petroleum Exploration ◽  
Gas Content ◽  
Gas Reservoirs ◽  
Gas Saturation ◽  
Shale Gas Reservoirs ◽  
Shale Reservoirs ◽  
Southeastern Sichuan Basin

Water saturation is one of the most important parameters in petroleum exploration and development. However, its calculation has been limited by the insufficient logging data required by a new technique that further influences the calculation of the free gas content. The accuracy of water saturation estimates is also a critical issue because it controls whether or not we can obtain an accurate gas saturation estimate. Organic matter plays an important role in shale-gas reservoirs, and the total organic carbon (TOC) indirectly controls the gas content and gas saturation. Hence, water saturation is influenced by inorganic and organic components. After analyzing the relationship among TOC, core water saturation, and conventional gas saturation, considering the influence of TOC on gas saturation in organic-rich shale reservoirs, we developed two new methods to improve the accuracy of water saturation estimates: the revised water saturation-TOC method and the water saturation separation method, in which Archie water saturation, modified total shale water saturation, and TOC are integrated. According to case studies of Longmaxi-Wufeng shale, southeastern Sichuan Basin, China, the water saturation results from these two methods in shale reservoirs with different lithologies are consistent with those from core analysis. We concluded that these two methods can be evaluated quickly and they effectively evaluate the water saturation of shale reservoirs.

scholarly journals Improved water saturation estimation in shaly sandstone through variable cementation factor

2021 ◽  
Author(s):  
Wan Zairani Wan Bakar ◽  
Ismail Mohd Saaid ◽  
Mohd Riduan Ahmad ◽  
Zulhelmi Amir ◽  
Nur Shuhadah Japperi ◽  
...  
Keyword(s):  
Water Saturation ◽  
Percentage Error ◽  
Saturation Model ◽  
Formation Factor ◽  
Archie’S Law ◽  
Straight Line ◽  
The Difference ◽  
Shaly Sandstone ◽  
Cementation Factor ◽  
Surface Conduction

AbstractEstimation of water saturation, Sw, in shaly sandstone is an intricate process. The surface conduction of clay minerals adds up to the electrolyte conduction in the pore spaces, thus generating high formation conductivity that overshadows the hydrocarbon effect. In each resistivity-based water saturation model, the key parameter is formation factor, F, which is typically derived from Archie’s Law. Referring to a log–log plot between formation factor and porosity, cementation factor reflects the slope of the straight line abiding Archie’s Law. In the case of shaly sandstone, derivation based on Archie’s Law in combination with Waxman–Smits equation leads to higher cementation factor, m*. In the shaly parts of the reservoir, high m* is counterbalanced by clay conductivity. Nonetheless, high m* used in clean parts increases Sw estimation. In this study, the variable cementation factor equation is introduced into the standard correlation of Sw versus Resistivity Index, RI, to develop a water saturation model with shaly sandstone parameters. Data retrieved from two fields that yielded mean arctangent absolute percentage error (MAAPE) were analysed to determine the difference between calculated and measured data within the 0.01–0.15 range for variable cementation factor method. The conventional method yielded maximum MAAPE at 0.46.

scholarly journals Detection of gas in landfills using geophysical methods

2007 ◽  
pp. 533-538
Author(s):  
M. Svensson ◽  
T. Dahlin ◽  
H. Rosqvist
Keyword(s):  
Geophysical Methods ◽  
Ground Surface ◽  
Pilot Test ◽  
Geophysical Method ◽  
Laser Technique ◽  
Gas Wells ◽  
Gas Leakage ◽  
Trapped Gas ◽  
Set Up ◽  
Resistivity Profiling

At NSR, Filboma landfill in Helsingborg, Sweden, a pilot test for detection of gas using the geophysical method resistivity profiling has shown promising results. Some of the results most likely showing trapped gas is shown. Due to the promising results two new separate tests are planned for 2008. The first test will focus on comparing gas leakage on the ground surface using laser technique and simultaneous resistivity monitoring. The second test is aiming to optimize the localisation of gas resources and monitoring the expected decrease of gas after the installation of gas wells. The set up for those tests will be presented and discussed

scholarly journals Assessment of the facial affiliation of local oil and gas objects based on geophysical data

2021 ◽  
Vol 21 (4) ◽  
pp. 241-247
Author(s):  
Boris A. Golovin ◽  
◽  
Konstantin B. Golovin ◽  
Marina V. Kalinnikova ◽  
Sergey A. Rudnev ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Facies Analysis ◽  
Geophysical Methods ◽  
Well Logging ◽  
Geophysical Data ◽  
Gas Content ◽  
Seismic Exploration ◽  
Core Material ◽  
Genetic Characteristics ◽  
Reservoir Potential

In the established practice of geological exploration for oil and gas conclusions about the facies belonging of the rocks of oil and gas basins and individual exploration areas were made mainly on the basis of the study of core material. Recently for this purpose the results of seismic exploration and well logging have been used. Geophysical methods despite their obvious progress are indirect and intermittent core sampling and incomplete coring make facies analysis difficult. Тhe study of cuttings during the well logging process makes it possible to fill this gap through direct continuous observations along the well section. The use of the whole complex of geophysical methods allows one to mutually compensate for the limitations and disadvantages of each of them and more fully and reliably assess the genetic characteristics and reservoir potential of productive deposits. Sequential accumulation, comparison and analysis of heterogeneous geophysical data make it possible to continuously refine apriori facies models and forecast oil and gas content which ultimately allows to optimize the directions and volumes of drilling.

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