Megaregional Seismic Lines as Indicators of Oil and Gas: ABSTRACT

Abstract Oil and gas exploration has resulted in over 300,000 km of linear disturbances known as seismic lines, throughout boreal peatlands across Canada. Sites are left with altered hydrologic and topographic conditions that prevent tree re-establishment. Restoration efforts have concentrated on tree recovery through mechanical mounding to re-create microtopography and support planted tree seedlings to block sightlines and deter predator use, but little is known about the impact of seismic line disturbance or restoration on peatland carbon cycling. This study looked at two mounding treatments and compared carbon dioxide and methane fluxes to untreated lines and natural reference areas in the first two years post-restoration. We found no significant differences in net ecosystem CO2 exchange, but untreated seismic lines were slightly more productive than natural reference areas and mounding treatments. Both restoration treatments increased ecosystem respiration, decreased net productivity by 6–21 gCO2m− 2d− 1, and created areas of increased methane emissions, including an increase in the contribution of ebullition, of up to 2000 mgCH4m− 2d− 1. Further research on this site to assess the longer-term impacts of restoration, as well as application on other sites with varied conditions, will help determine if these restoration practices are effective.

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Maintaining line of sight in oil and gas exploration: A case study from Mahakam Delta, Indonesia

The Leading Edge ◽

10.1190/tle39080558.1 ◽

2020 ◽

Vol 39 (8) ◽

pp. 558-565

Author(s):

Balakrishnan Kunjan ◽

Witan Ardjakusumah ◽

Kevin McDonald ◽

Hannah Booth ◽

Seda Rouxel ◽

...

Keyword(s):

Oil And Gas ◽

Airborne Gravity ◽

Quality Of Data ◽

Depth Migration ◽

Oil And Gas Exploration ◽

East Kalimantan ◽

Well Data ◽

Technical Effort ◽

Seismic Lines ◽

Over Time

In all exploration processes, the evaluation of basins, permits, and individual prospects changes over time with incremental availability and quality of data, technical effort expended, and knowledge gained. The NU prospect, located in the Mahakam Hilir PSC (East Kalimantan), is an example in which geologic chance of success (GCOS) predictions can change over time with increasing acquisition and availability of geophysical and geologic data and the studies done on them. We show how studies done on any one prospect or group of prospects can progressively increase/decrease the chance of at least one success in an exploration campaign of several wells. After a series of four wells was drilled in the PSC, which did not deliver commercial success, a change in approach was required to continue exploration. This included the acquisition of airborne gravity gradiometry data, initial trial prestack depth migration (PSDM) reprocessing of two key 1989 vintage 2D lines, acquisition of vintage well data from four Sambutan Field wells, acquisition of nine vintage 2D seismic lines over the field, and PSDM reprocessing of the nine 2D seismic lines. All data were then integrated to build a new geologic model. As a result, the NU prospect GCOS progressively moved from less than 10% to nearly 40%.

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Disturbing to restore? Effects of mounding on understory communities on seismic lines in treed peatlands

Canadian Journal of Forest Research ◽

10.1139/cjfr-2020-0092 ◽

2020 ◽

Vol 50 (12) ◽

pp. 1340-1351

Author(s):

Laureen F.I. Echiverri ◽

S. Ellen Macdonald ◽

Scott E. Nielsen

Keyword(s):

Community Composition ◽

Plant Communities ◽

Oil And Gas ◽

Reference Sites ◽

Oil And Gas Exploration ◽

Understory Plant ◽

Understory Plant Communities ◽

Understory Communities ◽

Associated Species ◽

Seismic Lines

In peatlands, microtopography strongly affects understory plant communities. Disturbance can result in a loss of microtopographic variation, primarily through the loss of hummocks. To address this, mounding treatments can be used to restore microtopography. We examined the effects of mounding on the understory vegetation on seismic lines in wooded fens. Seismic lines are deforested linear corridors (∼3 to 8 m wide) created for oil and gas exploration. Our objectives were to compare the recovery of understory communities on unmounded and mounded seismic lines and determine how recovery varies with microtopographic position. Recovery was evident in the unmounded seismic lines, with higher shrub and total understory cover at the “tops” of the small, natural hummocks than at lower microtopographic positions — much like the trends in adjacent treed fens. In contrast, mounding treatments that artificially created hummocks on seismic lines significantly changed understory communities. Mounded seismic lines had higher forb cover, much lower bryophyte cover, less variation along the microtopographic gradient, and community composition less similar to that of the reference sites than unmounded seismic lines due to higher abundance of marsh-associated species. Our results suggest that mounding narrow seismic lines can be detrimental to the recovery of the understory communities in treed peatlands.

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How linear features alter predator movement and the functional response

Interface Focus ◽

10.1098/rsfs.2011.0086 ◽

2012 ◽

Vol 2 (2) ◽

pp. 205-216 ◽

Cited By ~ 80

Author(s):

Hannah W. McKenzie ◽

Evelyn H. Merrill ◽

Raymond J. Spiteri ◽

Mark A. Lewis

Keyword(s):

Functional Response ◽

Oil And Gas ◽

First Passage Time ◽

Elliptic Partial Differential Equation ◽

Passage Time ◽

Encounter Rate ◽

Line Density ◽

Time Model ◽

Seismic Line ◽

Seismic Lines

In areas of oil and gas exploration, seismic lines have been reported to alter the movement patterns of wolves ( Canis lupus ). We developed a mechanistic first passage time model, based on an anisotropic elliptic partial differential equation, and used this to explore how wolf movement responses to seismic lines influence the encounter rate of the wolves with their prey. The model was parametrized using 5 min GPS location data. These data showed that wolves travelled faster on seismic lines and had a higher probability of staying on a seismic line once they were on it. We simulated wolf movement on a range of seismic line densities and drew implications for the rate of predator–prey interactions as described by the functional response. The functional response exhibited a more than linear increase with respect to prey density (type III) as well as interactions with seismic line density. Encounter rates were significantly higher in landscapes with high seismic line density and were most pronounced at low prey densities. This suggests that prey at low population densities are at higher risk in environments with a high seismic line density unless they learn to avoid them.

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Understanding the hydrocarbon prospect of Buzdar block, Southern Indus basin, Pakistan, by using 2-D seismic data: A case study

Contributions to Geophysics and Geodesy ◽

10.2478/congeo-2019-0013 ◽

2019 ◽

Vol 49 (3) ◽

pp. 249-263

Author(s):

Hamid Hussain ◽

Zhang Shuangxi ◽

Muhammad Abid

Keyword(s):

Oil And Gas ◽

Basic Mechanism ◽

Indus Basin ◽

Normal Faults ◽

Contour Maps ◽

Near Fault ◽

Vsp Data ◽

Western Side ◽

Lower Goru Formation ◽

Seismic Lines

Abstract The sub-surface structural analysis to understand the geology and tectonics of an area is always useful to locate the hydrocarbon resources. Oil and gas based energy supplies have become a vital source for Pakistan, which is passing through an era of severe energy crisis. The study area, Buzdar block, in the southern Indus Basin is tectonically an extensional regime and is expected to have a huge hydrocarbon potential. In this study, we did the interpretation of the migrated seismic lines of the 872-SGR-527, 872-SGR-529, 872-SGR-531, 872-SGR-532 of Buzdar block, District TandoAllahyar, Sindh. The lines 872-SGR-529, 872-SGR-531, 872-SGR-532 were oriented W–E whereas the line 872-SGR-527 was oriented NW–SE. The obtained data was analysed and three reflectors were marked named top Khadro Formation, top lower Goru formation and top Chiltan limestone (probable). Through this study faults have been also marked on seismic lines which are normal faults by nature; collectively form horsts and grabens which is the evidence of effect of extensional tectonics in the area. Time contour maps were also generated. After that, time was converted into depth with the help of well velocity from VSP data for lower Goru formation and average velocity for Chiltan limestone (probable) from regression analysis. Finally, depth contour maps were generated which helped to know the basic mechanism of tectonic movement in the area. On the basis of present analysis we propose that a well may be drilled at Lower Goru formation near fault F1 on western side at a depth of 1370 meters and at 1290 meters near fault F4 on eastern side.

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Seismic Characteristics of Mud Diapir in Song Hong Basin, Offshore Vietnam

Iraqi Geological Journal ◽

10.46717/igj.54.2a.1ms-2021-07-22 ◽

2021 ◽

Vol 54 (2A) ◽

pp. 1-10

Author(s):

Anh Ngoc Le

Keyword(s):

Oil And Gas ◽

High Amplitude ◽

High Energy ◽

Hydrocarbon Generation ◽

Red River Basin ◽

Seismic Characteristics ◽

Mud Diapir ◽

The Relationship ◽

Seismic Lines ◽

Amplitude Reflection

Seismic characteristics of mud diapir has been investigate over an area of 3900 km2, located in the central part of Song Hong basin, using four 2D seismic lines. There are six mud diapirs and three mud pipes have been documented. The core of the diapir is characterized as a zone of chaotic, disrupted seismic reflection, with the amplitude reflection ranging from low the high. High amplitude reflections are distributed in the top of the some diapir, which is possibly related to the gas accumulation. They are in different sizes, shapes, and the relationship with surrounding rock. They are characterized as deep sourced, high energy rooting from Oligocene/early Miocene shale layers. This organic rich shale rocks are in the oil and gas windows, thus their hydrocarbon generation combining with the tectonic inversion during Miocene make the overpressured shale and therefore rising the diaipirs. The area has experienced several phases of eruption in Middle Miocene, Late Miocene, Late Pliocene and Present day. The discovery and identification of the occurrence of mud diapirs implied a great potential for prediction of structural traps in the central part of the Red River Basin.

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Recovery of Pindan vegetation on seismic lines

The Rangeland Journal ◽

10.1071/rj19051 ◽

2019 ◽

Vol 41 (5) ◽

pp. 393

Author(s):

Stuart J. Dawson ◽

Peter J. Adams ◽

Kris I. Waddington ◽

Katherine E. Moseby ◽

Patricia A. Fleming

Keyword(s):

Vegetation Structure ◽

Oil And Gas ◽

Vegetation Recovery ◽

The West ◽

Seismic Surveys ◽

Vegetation Surveys ◽

Oil And Gas Resources ◽

Paired Control ◽

The 1960S ◽

Seismic Lines

Exploration for oil and gas resources requiring the clearing of seismic lines has been occurring in central and northern Australia for many years. For example, seismic surveys have been conducted in the West Kimberley region of Western Australia since the 1960s. Despite this being a widespread practice, the recovery of vegetation on seismic lines has not been well studied. To better understand vegetation recovery in the West Kimberley, we conducted vegetation surveys on recovering seismic lines cleared using a raised-blade technique, from ∼two months to 4.9 years post-clearing, and compared them to paired control plots. Generally, the vegetation structure and community composition on seismic lines recovered quickly, with no discernible difference between control and seismic plots that were cleared more than 6 months prior. Some individual vegetation characteristics (e.g. understorey density and overstorey cover) recovered slowly, whereas other characteristics such as the number of individual grasses, recovered quickly. Vegetation recovery was confounded by the time since fire, which accounted for differences in vegetation structure at 1–2 years and 3–4 years since clearing. The fast recovery rate observed suggests that raised-blade clearing may not present a lasting impact on Pindan vegetation in the West Kimberley.

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High Precision Altimeter Demonstrates Simplification and Depression of Microtopography on Seismic Lines in Treed Peatlands

Forests ◽

10.3390/f10040295 ◽

2019 ◽

Vol 10 (4) ◽

pp. 295 ◽

Cited By ~ 4

Author(s):

Cassondra Stevenson ◽

Angelo Filicetti ◽

Scott Nielsen

Keyword(s):

High Precision ◽

Oil And Gas ◽

Tree Regeneration ◽

Tree Seedlings ◽

Minor Variation ◽

Topographic Complexity ◽

Oil And Gas Exploration ◽

Linear Forest ◽

Seismic Lines

Seismic lines are linear forest clearings used for oil and gas exploration. The mechanical opening of forests for these narrow (3–10 meter) lines is believed to simplify microtopographic complexity and depress local topographic elevation. In treed peatlands, simplified microtopography limits tree regeneration by removing favourable microsites (hummocks) for tree recruitment and increasing the occurrence of flooding that reduces survival of tree seedlings. Little, however, has been done to quantify the microtopography of seismic lines and specifically the degree of alteration. Here, we measured microtopography at 102 treed peatland sites in northeast Alberta, Canada using a high precision hydrostatic altimeter (ZIPLEVEL PRO-2000) that measured variation in local topography of seismic lines and adjacent paired undisturbed forests. Sites were separated into four peatland ecosite types and the presence or absence of recent (<22 years) wildfires. Paired t-tests were used to compare microtopographic complexity and depression depth of seismic lines compared with adjacent forests. Microtopographic complexity on seismic lines was simplified by 20% compared to adjacent stands with no significant change between recently burned and unburned sites, nor between ecosites. Not only were seismic lines simplified, but they were also depressed in elevation by an average of 8 cm compared to adjacent forests with some minor variation between ecosites observed, but again not with recent wildfires. Thus, simplification of microtopographic complexity and the creation of depressions can persist decades after initial disturbance with some differences between peatland ecosites, implying the need for ecosite-specific restoration of topographic complexity. The importance of microtopography for tree regeneration on seismic lines remains an important question for reforestation of these disturbances and thus long-term recovery of habitat for species dependent on undisturbed peatlands, including woodland caribou.

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Seismic lines in the boreal and arctic ecosystems of North America: environmental impacts, challenges, and opportunities

Environmental Reviews ◽

10.1139/er-2017-0080 ◽

2018 ◽

Vol 26 (2) ◽

pp. 214-229 ◽

Cited By ~ 33

Author(s):

Anna Dabros ◽

Matthew Pyper ◽

Guillermo Castilla

Keyword(s):

North America ◽

Environmental Impacts ◽

Oil And Gas ◽

Environmental Changes ◽

Oil And Gas Industry ◽

The United States ◽

Arctic Ecosystems ◽

Seismic Line ◽

Wide Range ◽

Seismic Lines

The oil and gas industry has grown significantly throughout the boreal and arctic ecosystems of North America. A major feature of the ecological footprint of oil and gas exploration is seismic lines—narrow corridors used to transport and deploy geophysical survey equipment. These lines, which traverse forests, tundra, uplands, and peatlands, were historically up to 10 m wide. Over the past decade, seismic lines have decreased in width (in some cases down to 1.75–3 m); however, their density has increased drastically and their construction is expected to continue in regions of Canada and the United States that are rich in oil and gas resources. We examine the literature related to the environmental impacts of, and restoration and reclamation efforts associated with, seismic lines in the boreal and arctic ecosystems of North America. With respect to conventional seismic lines, numerous studies report significant and persistent environmental changes along these lines and slow recovery of vegetation that translates into a lasting fragmentation of the landscape. This fragmentation has many ramifications for biodiversity and ecosystem processes, including significant implications for threatened woodland caribou herds. While modern, low-impact seismic lines have comparatively lower ecological effects at the site-level, their high density and associated potential edge effects suggest that their actual environmental impact may be underestimated. Seismic line restoration is a critical aspect of future integrated landscape management in hydrocarbon-rich regions of the boreal-arctic, and if widely applied, has the potential to benefit a wide range of species and maintain or re-establish key ecosystem services such as carbon sequestration and biodiversity.

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Automatic Linear Disturbance Footprint Extraction Based on Dense Time-Series Landsat Imagery

Volume 1: Design and Construction; Environment; Pipeline Automation and Measurement ◽

10.1115/ipc2014-33172 ◽

2014 ◽

Author(s):

Zhaohua Chen ◽

Bill Jefferies ◽

Paul Adlakha ◽

Bahram Salehi ◽

Des Power

Keyword(s):

Time Series ◽

Satellite Data ◽

Oil And Gas ◽

Time Series Data ◽

Landsat Imagery ◽

Low Cost ◽

Remote Sensing Data ◽

Series Data ◽

Linear Features ◽

Seismic Lines

Linear disturbances from the construction of pipelines, roads and seismic lines for oil and gas extraction and mining have caused landscape changes in Western Canada; however these linear features are not well recorded. Inventory maps of pipelines, seismic lines and temporary access routes created by resource exploration are essential to understanding the processes causing ecological changes in order to coordinate resource development, emergency response and wildlife management. Mapping these linear disturbances traditionally relies on manual digitizing from very high resolution remote sensing data, which usually limits results to small operational area. Extending mapping to large areas is challenging due to complexity of image processing and high logistical costs. With increased availability of low cost satellite data, more frequent and regular observations are available and offer potential solutions for extracting information on linear disturbances. This paper proposes a novel approach to incorporate spectral, geometric and temporal information for detecting linear features based on time series data analysis of regularly acquired, and low cost satellite data. This approach involves two steps: multi-scale directional line detection and line updating based on time series analysis. This automatic method can effectively extract very narrow linear features, including seismic lines, roads and pipelines. The proposed method has been tested over three sites in Alberta, Canada by detecting linear disturbances occurring over the period of 1984–2013 using Landsat imagery. It is expected that extracted linear features would be used to facilitate preparation of baseline maps and up-to-date information needed for environmental assessment, especially in extended remote areas.

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