Current Land and Waterborne Geophysical Methods for Guiding Horizontal Directional Drilling and Trenching Along Pipeline Right-of-Ways

2016 ◽  
Author(s):  
Paul Bauman ◽  
Alastair McClymont ◽  
Landon Woods ◽  
Erin Ernst
Keyword(s):  
Seismic Refraction ◽  
Geophysical Methods ◽  
Cost Effective ◽  
The Arctic ◽  
Directional Drilling ◽  
Borehole Geophysics ◽  
Discontinuous Permafrost ◽  
Refraction Seismic ◽  
Geotechnical Investigations ◽  
Geophysical Surveys

In Western Canada, oil and natural gas pipeline projects are being considered that will move hydrocarbons from the Prairie Provinces and British Columbia, to the Pacific Ocean, the Atlantic, and even potentially the Arctic. Along the proposed right-of-ways, the pipeline engineers will encounter challenging and varied terrain, including discontinuous permafrost, creek and river crossings, glaciomarine clays, thick muskeg, and other subsurface conditions that require specialized engineering planning in advance of construction. Geophysical surveys, in support of geotechnical investigations, provide continuous subsurface information to help inform design challenges associated with the many terrain challenges. Some geophysical surveys to be considered include electrical resistivity tomography (ERT), induced polarization (IP), seismic refraction, seismic reflection, multi-channel analysis of surface waves (MASW), ground penetrating radar (GPR), and borehole geophysics. Typically, a combination of several geophysical surveys along with drilling information, are optimal for the cost-effective site characterization of problematic segments of proposed pipeline right-of-ways.

Efficiency Of Integrated Seismic Methods Approach To Near-Surface Characterization

2020 ◽  
Author(s):  
Irena Gjorgjeska ◽  
Vlatko Sheshov ◽  
Kemal Edip ◽  
Dragi Dojchinovski
Keyword(s):  
Surface Characterization ◽  
Seismic Refraction ◽  
Geophysical Methods ◽  
Cost Effective ◽  
Integrated Approach ◽  
Image Resolution ◽  
Future Research ◽  
Near Surface ◽  
Seismic Methods ◽  
Refraction Seismic

<p>Surface seismic methods are among the most popular, widely accepted, geophysical methods for near-surface characterization. The most practical and effective way to perform in-situ measurements and data processing using different seismic methods as are seismic refraction, seismic reflection and MASW method in an integrated approach is presented in this paper. Each method has some advantages and limitations, but their application in an integrated approach provides higher accuracy in subsurface modeling. The same seismic equipment and, in most of the cases, the same acquisition parameters were used, enabling time and cost effective survey for subsurface characterization. The choice of these parameters was not random. Experimental research by use of the above-mentioned seismic methods was carried out in a long period in order to define the optimal parameters for successful application of an integrated technique in future research. During this survey, particular attention was paid to the influence of the acquisition parameters on the dispersion image resolution in the MASW surveys and extraction of an effective dispersion curve.</p><p>The results of the performed surveys at characteristic locations in R. North Macedonia are presented to show the efficiency of the combined methods approach.</p>

scholarly journals A comparison of seismic and radar methods to establish the thickness and density of glacier snow cover

2013 ◽  
Vol 54 (64) ◽  
pp. 73-82 ◽  
Author(s):  
Adam D. Booth ◽  
Andrew Mercer ◽  
Roger Clark ◽  
Tavi Murray ◽  
Peter Jansson ◽  
...  
Keyword(s):  
Lower Layer ◽  
Effective Means ◽  
Seismic Refraction ◽  
Geophysical Methods ◽  
Ground Truth ◽  
Snow Layer ◽  
Refraction Seismic ◽  
Geophysical Surveys ◽  
Glacier Ice ◽  
Snow Thickness

AbstractWe show that geophysical methods offer an effective means of quantifying snow thickness and density. Opportunistic (efficient but non-optimized) seismic refraction and ground-penetrating radar (GPR) surveys were performed on Storglaciären, Sweden, co-located with a snow pit that shows the snowpack to be 1.73 m thick, with density increasing from ∼120 to ∼500 kg m–3(with a +50 kg m–3anomaly between 0.73 and 0.83 m depth). Depths estimated for two detectable GPR reflectors, 0.76 ±0.02 and 1.71 ± 0.03 m, correlate extremely well with ground-truth observations. Refraction seismic predicts an interface at 1.90 ± 0.31 m depth, with a refraction velocity (3730 ± 190 ms–1) indicative of underlying glacier ice. For density estimates, several standard velocity-density relationships are trialled. In the best case, GPR delivers an excellent density estimate for the upper snow layer (observed = 321 ± 74 kg m–3, estimated = 319 ± 10 kgm–3) but overestimates the density of the lower layer by 20%. Refraction seismic delivers a bulk density of 404 ±22 kgm–3compared with a ground-truth average of 356 ± 22 kg m–3. We suggest that geophysical surveys are an effective complement to mass-balance measurements (particularly for controlling estimates of snow thickness between pits) but should always be validated against ground-truth observations.

The Application of Near-Surface Geophysics at Proposed Pipeline River Crossings: A Comparative Overview of Various Techniques and Their Associated Capabilities and Limitations

2002 ◽  
Author(s):  
Paul Tarrant ◽  
David Baines
Keyword(s):  
Large Diameter ◽  
Seismic Refraction ◽  
Directional Drilling ◽  
Near Surface ◽  
Design Engineers ◽  
Geotechnical Investigations ◽  
Geophysical Surveys ◽  
Ground Conditions ◽  
Borehole Drilling ◽  
Near Surface Geophysics

The cost, design, and in some instances, feasibility of directional drilling large diameter or lengthy pipeline river crossings is primarily dependent on ground conditions encountered during construction. Geotechnical investigations are commonly used to explore and assess subsurface conditions at proposed crossings. Ground conditions are determined using borehole drilling and near surface geophysics. Borehole drilling provides subsurface sediment stratigraphy and depth to bedrock information. Geophysics is used to provide information between borehole locations or where borehole drilling is determined to be too difficult or too costly. When used to augment borehole results, geophysical surveys provide more complete geologic cross-section models throughout the length of a proposed directional drill path. This paper presents an overview of the more common geophysical methodologies used to profile subsurface conditions at proposed pipeline crossings. The methods discussed include ground penetrating radar (GPR), seismic refraction profiling and electrical resistivity tomography (ERT). The appropriateness and feasibility of each method is discussed in terms relating to investigation objectives of geotechnical and pipeline design engineers. All three methods were applied to two survey lines at a typical river crossing site on the Bow River, downstream from Calgary, Alberta. Results from the overlapping surveys are presented and the capabilities and limitations for each method compared. Borehole information obtained within the survey area is used to corroborate the interpreted geophysical results.

The Geophysical Toolbox: A Practical Approach to Pipeline Design and Construction

2004 ◽  
Author(s):  
J. Henderson ◽  
M. Bowman ◽  
J. Morrissey
Keyword(s):  
Seismic Refraction ◽  
Geophysical Methods ◽  
Value Added ◽  
Cost Effective ◽  
Case Histories ◽  
Electrical Imaging ◽  
Geophysical Surveys ◽  
Geophysical Technique ◽  
Pipeline Design ◽  
Design And Construction

Geophysical surveys map variations in physical properties of subsurface materials, many of which can have a direct impact on pipeline design and construction. This paper provides an overview of complementary geophysical methods available in the geophysical toolbox and shows, through the use of case histories, examples of the applicability of the methods for specific pipeline design and construction scenarios. In the context of pipeline design and construction, the objectives of a geophysical survey typically include one or more of the following applications: • muskeg mapping (thickness, lateral extent); • permafrost delineation (variations in ice content, frozen/unfrozen boundaries); • depth to bedrock; • rippability of bedrock; • soil type delineation (corrosion protection, granular inventories); • subsurface conditions at water crossings for horizontal directional drill planning using detailed investigations (boulder horizons, abandoned workings, depth to bedrock). To successfully address these objectives, it is often necessary to utilize more than one geophysical technique. Geophysical methods commonly employed in pipeline investigations include the following: • seismic refraction (marine and land based); • seismic reflection (marine and land based); • electromagnetics; • electrical imaging; • ground penetrating radar (marine and land based); • sonar. The fullest utility of geophysical information is achieved when combined with complementary approaches to provide the end-user with a value-added, cost effective approach. These other method include: airphoto interpretation, satellite imagery, and drilling. The incorporation of auxiliary data sets results in geophysical sections that provide a means of interpolating subsurface conditions between drill holes and reducing the risk associated with encountering surprises. These sections can also be used to provide for more accurate cost estimates by their inclusion in bid documents while at the same time ensuring a better data base for pipeline design. In addition to the advantages of using a geophysical toolbox, the ramifications of the pitfalls of geophysical approaches will also be discussed through the use of case histories illustrating situations in which an inappropriate geophysical technique was applied.

Integration of Multi-geophysical Approaches to Identify Potential Pathways of Heavy Metals Contamination - A Case Study in Zeida, Morocco

2020 ◽  
Vol 25 (3) ◽  
pp. 415-423
Author(s):  
Ahmed Lachhab ◽  
El Mehdi Benyassine ◽  
Mohamed Rouai ◽  
Abdelilah Dekayir ◽  
Jean C. Parisot ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Seismic Velocity ◽  
Seismic Refraction ◽  
Geophysical Methods ◽  
Low Frequency ◽  
Electrical Current ◽  
P Wave ◽  
Low Resistivity ◽  
Refraction Tomography ◽  
Geophysical Surveys

The tailings of Zeida's abandoned mine are found near the city of Midelt, in the middle of the high Moulouya watershed between the Middle and the High Atlas of Morocco. The tailings occupy an area of about 100 ha and are stored either in large mining pit lakes with clay-marl substratum or directly on a heavily fractured granite bedrock. The high contents of lead and arsenic in these tailings have transformed them into sources of pollution that disperse by wind, runoff, and seepage to the aquifer through faults and fractures. In this work, the main goal is to identify the pathways of contaminated water with heavy metals and arsenic to the local aquifers, water ponds, and Moulouya River. For this reason, geophysical surveys including electrical resistivity tomography (ERT), seismic refraction tomography (SRT) and very low-frequency electromagnetic (VLF-EM) methods were carried out over the tailings, and directly on the substratum outside the tailings. The result obtained from combining these methods has shown that pollutants were funneled through fractures, faults, and subsurface paleochannels and contaminated the hydrological system connecting groundwater, ponds, and the river. The ERT profiles have successfully shown the location of fractures, some of which extend throughout the upper formation to depths reaching the granite. The ERT was not successful in identifying fractures directly beneath the tailings due to their low resistivity which inhibits electrical current from propagating deeper. The seismic refraction surveys have provided valuable details on the local geology, and clearly identified the thickness of the tailings and explicitly marked the boundary between the Triassic formation and the granite. It also aided in the identification of paleochannels. The tailings materials were easily identified by both their low resistivity and low P-wave velocity values. Also, both resistivity and seismic velocity values rapidly increased beneath the tailings due to the compaction of the material and lack of moisture and have proven to be effective in identifying the upper limit of the granite. Faults were found to lie along the bottom of paleochannels, which suggest that the locations of these channels were caused by these same faults. The VLF-EM surveys have shown tilt angle anomalies over fractured areas which were also evinced by low resistivity area in ERT profiles. Finally, this study showed that the three geophysical methods were complementary and in good agreement in revealing the pathways of contamination from the tailings to the local aquifer, nearby ponds and Moulouya River.

Application of geophysical methods for the investigation of the large gravitational mass movement of Séchilienne, France

2005 ◽  
Vol 42 (4) ◽  
pp. 1105-1115 ◽  
Author(s):  
O Meric ◽  
S Garambois ◽  
D Jongmans ◽  
M Wathelet ◽  
J L Chatelain ◽  
...  
Keyword(s):  
Rock Mass ◽  
Mass Movement ◽  
Seismic Refraction ◽  
Geophysical Methods ◽  
Time Lapse ◽  
Gravitational Mass ◽  
Electrical Tomography ◽  
Refraction Tomography ◽  
Geophysical Surveys ◽  
Geophysical Techniques

Several geophysical techniques (electromagnetic profiling, electrical tomography, seismic refraction tomography, and spontaneous potential and seismic noise measurement) were applied in the investigation of the large gravitational mass movement of Séchilienne. France. The aim of this study was to test the ability of these methods to characterize and delineate the rock mass affected by this complex movement in mica schists, whose lateral and vertical limits are still uncertain. A major observation of this study is that all the zones strongly deformed (previously and at present) by the movement are characterized by high electrical resistivity values (>3 kΩ·m), in contrast to the undisturbed mass, which exhibits resistivity values between a few hundred and 1 kΩ·m. As shown by the surface observations and the seismic results, this resistivity increase is due to a high degree of fracturing associated with the creation of air-filled voids inside the mass. Other geophysical techniques were tested along a horizontal transect through the movement, and an outstanding coherency appeared between the geophysical anomalies and the displacement rate curve. These preliminary results illustrate the benefits of combined geophysical techniques for characterizing the rock mass involved in the movement. Results also suggest that monitoring the evolution of the rock mass movement with time-lapse geophysical surveys could be beneficial.Key words: gravitational movement, geophysical methods, Séchilienne.

The use of geophysical prospecting for imaging active faults in the Roer Graben, Belgium

Geophysics ◽  
2001 ◽  
Vol 66 (1) ◽  
pp. 78-89 ◽  
Author(s):  
Donat Demanet ◽  
François Renardy ◽  
Kris Vanneste ◽  
Denis Jongmans ◽  
Thierry Camelbeeck ◽  
...  
Keyword(s):  
High Resolution ◽  
Physical Properties ◽  
Fault Zone ◽  
Geophysical Methods ◽  
Depth Range ◽  
Electrical Tomography ◽  
Reflection Seismic ◽  
Refraction Seismic ◽  
Geophysical Surveys ◽  
Geophysical Techniques

As part of a paleoseismological investigation along the Bree fault scarp (western border of the Roer Graben), various geophysical methods [electrical profiling, electromagnetic (EM) profiling, refraction seismic tests, electrical tomography, ground‐penetrating radar (GPR), and high‐resolution reflection seismic profiles] were used to locate and image an active fault zone in a depth range between a few decimeters to a few tens of meters. These geophysical investigations, in parallel with geomorphological and geological analyses, helped in the decision to locate trench excavations exposing the fault surfaces. The results could then be checked with the observations in four trenches excavated across the scarp. Geophysical methods pointed out anomalies at all sites of the fault position. The contrast of physical properties (electrical resistivity and permittivity, seismic velocity) observed between the two fault blocks is a result of a differences in the lithology of the juxtaposed soil layers and of a change in the water table depth across the fault. Extremely fast techniques like electrical and EM profiling or seismic refraction profiles localized the fault position within an accuracy of a few meters. In a second step, more detailed methods (electrical tomography and GPR) more precisely imaged the fault zone and revealed some structures that were observed in the trenches. Finally, one high‐resolution reflection seismic profile imaged the displacement of the fault at depths as large as 120 m and filled the gap between classical seismic reflection profiles and the shallow geophysical techniques. Like all geophysical surveys, the quality of the data is strongly dependent on the geologic environment and on the contrast of the physical properties between the juxtaposed formations. The combined use of various geophysical techniques is thus recommended for fault mapping, particularly for a preliminary investigation when the geological context is poorly defined.

GEOPHYSICAL METHODS ADAPTED TO HIGHWAY ENGINEERING PROBLEMS

Geophysics ◽  
1952 ◽  
Vol 17 (3) ◽  
pp. 505-530 ◽  
Author(s):  
R. Woodward Moore
Keyword(s):  
Seismic Refraction ◽  
Geophysical Methods ◽  
Engineering Structures ◽  
Highway Engineering ◽  
Earth Resistivity ◽  
The Earth ◽  
Ore Bodies ◽  
Geophysical Surveys ◽  
Engineering Problems ◽  
Test Use

Of the several geophysical methods used in exploration for oil and useful ore bodies, the earth‐resistivity and seismic‐refraction tests have been found to be the most adaptable to the shallow tests generally required in highway construction work. Of these, the earth‐resistivity test is the faster and has a wider range of application to highway problems than does the seismic test. Use of both methods of tests in subsurface explorations for engineering structures is expanding. The paper cites a growing need for a more thorough subsurface investigation of all engineering structure sites and gives examples of field data obtained by the Bureau of Public Roads when making preliminary geophysical surveys of proposed highway locations or structure sites. The economic aspects and the advantages and limitations of the two methods of test are discussed with particular reference to their application to highway engineering problems.

Upscaling of geophysical measurements: A methodology for the estimation of the total ground ice content at two study sites in the dry Andes of Chile and Argentina

2020 ◽  
Author(s):  
Tamara Mathys ◽  
Christin Hilbich ◽  
Cassandra E.M. Koenig ◽  
Lukas Arenson ◽  
Christian Hauck
Keyword(s):  
Hydrological Cycle ◽  
Spatial Scales ◽  
Geophysical Methods ◽  
Central Andes ◽  
Permafrost Degradation ◽  
Rock Glacier ◽  
Ground Ice ◽  
Refraction Seismic ◽  
Geophysical Surveys ◽  
Ice Content

<p>With climate change and the associated continuing recession of glaciers, water security, especially in regions depending on the water supply from glaciers, is threatened. In this context, the understanding of permafrost distribution and its degradation is of increasing importance as it is currently debated whether ground ice can be considered as a significant water reservoir and as an alternative resource of fresh water that could potentially moderate water scarcity during dry seasons in the future. Thus, there is a pressing need to better understand how much water is stored as ground ice in areas with extensive permafrost occurrence and how meltwater from permafrost degradation may contribute to the hydrological cycle in the region.</p><p>Although permafrost and permafrost landforms in the Central Andes are considered to be abundant and well developed, the data is scarce and understanding of the Andean cryosphere lacking, especially in areas devoid of glaciers and rock glaciers.</p><p>In the absence of boreholes and test pits, geophysical investigations are a feasible and cost-effective technique to detect ground ice occurrences within a variety of landforms and substrates. In addition to the geophysical surveys themselves, upscaling techniques are needed to estimate ground ice content, and thereby future water resources, on larger spatial scales. To contribute to reducing the data scarcity regarding ground ice content in the Central Andes, this study focuses on the permafrost distribution and the ground ice content (and its water equivalent) of two catchments in the semi-arid Andes of Chile and Argentina. Geophysical methods (Electrical Resistivity Tomography, ERT and Refraction Seismic Tomography, RST) were used to detect and quantify ground ice in the study regions in the framework of environmental impact assessments in mining areas. Where available, ERT and RST measurements were quantitatively combined to estimate the volumetric ground ice content using the Four Phase Model (Hauck et al., 2011). Furthermore, we developed one of the first methodologies for the upscaling of these geophysical-based ground ice quantifications to an entire catchment in order to estimate the total ground ice volume in the study areas.</p><p>In this contribution we will present the geophysical data, the upscaling methodology used to estimate total ground ice content (and water equivalent) of permafrost areas, and some first estimates of total ground ice content in rock glacier and rock glacier free areas and compare them to conventional estimates using remotely sensed data.</p><p> </p><p>Hauck, C., Böttcher, M., and Maurer, H. (2011). A new model for estimating subsurface ice content based on combined electrical and seismic datasets, The Cryosphere, 5: 453-468.</p>

Applications of geophysical techniques in permafrost regions

1977 ◽  
Vol 14 (1) ◽  
pp. 117-127 ◽  
Author(s):  
W. J. Scott ◽  
J. A. Hunter
Keyword(s):  
Seismic Velocity ◽  
Seismic Refraction ◽  
Beaufort Sea ◽  
Test Site ◽  
The Arctic ◽  
Seismic Profiles ◽  
Refraction Seismic ◽  
Lake Bottom ◽  
Ice Content ◽  
The Hill

This paper reports the results of some recent geophysical experiments carried out in the Arctic with a variety of methods. In the Beaufort Sea, seismic refraction profiles obtained with both source and receivers on the seabottom indicate the presence of discontinuous near-bottom high-velocity (4200 m/s) material interpreted to be presently aggrading permafrost. Spring-time resistivity soundings taken through the ice in Kugmallit Bay, Beaufort Sea, show the top of permafrost at about 50 m below the bottom. Even for 5-km spreads, the base of permafrost was not observed.Off the southeast coast of Melville Island, refraction seismic profiles shot on the seabottom and resistivity soundings made through summer ice yielded data which correlate with known sub-bottom geology, but which gave no clear indication of either presence or absence of permafrost.Seismic and resistivity measurements made at a number of control sites in the Arctic Islands yielded typical velocities of 3500 m/s and resistivities of 1 × 106 ohm-m for ice-saturated sands. Some correlation was observed between seismic velocity and moisture contents in the range from 10% to 40%.Seismic and resistivity results in IOL Lake at the Involuted Hill test site, Tuktoyaktuk Peninsula, suggest the absence of permafrost under some parts of the lake bottom. On the hill itself, seismic up-hole shooting and VLF resistivity profiling give interpretations of ice distribution which correlate well with drill control. Gamma-gamma logs taken in some of the drill holes correlate well with ice content logged during drilling.

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