Mapping Quaternary paleovalleys and drift thickness using petrophysical logs, northeast British Columbia, Fontas map sheet, NTS 94IThis article is one of a selection of papers published in this Special Issue on the theme Geology of northeastern British Columbia and northwestern Alberta: diamonds, shallow gas, gravel, and glaciers.

2008 ◽  
Vol 45 (5) ◽  
pp. 577-591 ◽  
Author(s):  
Adrian S. Hickin ◽  
Ben Kerr ◽  
Derek G. Turner ◽  
Tom E. Barchyn
Keyword(s):  
British Columbia ◽  
Oil And Gas ◽  
Special Issue ◽  
Quaternary Sediments ◽  
Shallow Gas ◽  
Gas Well ◽  
Well Drilling ◽  
Bedrock Topography ◽  
Petrophysical Logs ◽  
Selection Of

The relatively subdued topography of British Columbia’s northern interior plains does not reflect the irregular, buried bedrock surface. Many areas have been deeply incised by preglacial rivers that have subsequently filled with a succession of Quaternary sediments. In this study, oil and gas petrophysical logs, drill chip samples, water well logs, and surficial and bedrock outcrop maps were used to model the bedrock topography of the Fontas map sheet (NTS 94I). The modelled data produced several depressions that are interpreted to be paleovalleys incised into the soft Cretaceous shale of the Fort St. John Group. Understanding the geometry, thickness, and stratigraphy of the drift has considerable safety and resource management implications as artesian aquifers and natural gas were encountered in the drift during oil and gas well drilling. Four major paleovalleys are suggested. The most dominant paleovalley (Kotcho–Hoffard Paleovalley) is located south of the Etsho Plateau and trends west-southwest across the map area. A second depression occurs within the loop of the Hay River and may be a tributary of the Kotcho–Hoffard Paleovalley that links with the Rainbow Paleovalley in Alberta. A third paleovalley is mapped south of the Sahtaneh River (Kyklo Creek Paleovalley) and is either a tributary to, or crosscuts the Kotcho–Hoffard Paleovalley. The Niteal Creek Paleovalley is located between the Fontas and Sikanni Chief rivers. Its geometry is speculative as there are sparse data, but it may be a tributary of the Kotcho–Hoffard Paleovalley.

AMS-dated late Pleistocene taiga vole (Rodentia: Microtus xanthognathus) from northeast British Columbia, Canada: a cautionary lesson in chronologyThis article is one of a selection of papers published in this Special Issue on the theme Geology of northeastern British Columbia and northwestern Alberta: diamonds, shallow gas, gravel, and glaciers.

2008 ◽  
Vol 45 (5) ◽  
pp. 611-618 ◽  
Author(s):  
Richard J. Hebda ◽  
James A. Burns ◽  
Marten Geertsema ◽  
A. J. Timothy Jull
Keyword(s):  
British Columbia ◽  
Late Pleistocene ◽  
Bone Collagen ◽  
Laurentide Ice Sheet ◽  
Special Issue ◽  
Cautionary Note ◽  
Shallow Gas ◽  
Peace River ◽  
Elusive Species ◽  
Selection Of

Dissected colluvial sediments on a Peace River terrace at Bear Flat, northeast British Columbia enclosed a late Pleistocene micromammalian faunule. The fossil remains, including a few loosely articulated skulls and mandibles, were dominated by taiga voles ( Microtus xanthognathus ). The Bear Flat site constitutes the second fossil occurrence in the region of this elusive species, which is unknown in British Columbia in historic times. The late Pleistocene age, determined by accelerator mass spectrometry directly on taiga vole bone collagen, is consistent with the ages of widespread taiga vole records peripheral to the Laurentide ice sheet in western, mid-western, and eastern North America. The presence of allo-chronous remains within a comprehensively dated sedimentary sequence provides a cautionary note about straightforward acceptance of relative stratigraphic dating.

Quaternary stratigraphy and glacial history of the Peace River valley, northeast British ColumbiaThis article is one of a selection of papers published in this Special Issue on the theme Geology of northeastern British Columbia and northwestern Alberta: diamonds, shallow gas, gravel, and glaciers.

2008 ◽  
Vol 45 (5) ◽  
pp. 549-564 ◽  
Author(s):  
Gregory M.D. Hartman ◽  
John J. Clague
Keyword(s):  
British Columbia ◽  
River Valley ◽  
Quaternary Sediments ◽  
Shallow Gas ◽  
Peace River ◽  
Last Glaciation ◽  
Quaternary Stratigraphy ◽  
History Of ◽  
Late Wisconsinan ◽  
Selection Of

Two Cordilleran and three Laurentide glacial advances are recorded in Quaternary sediments and landforms in the Peace River valley, northeast British Columbia. The advances are inferred from fluvial gravels, glaciolacustrine sediments, and tills within nested paleovalleys excavated during three interglaciations and from the distribution of granitoid clasts derived from the Canadian Shield. Till of the last (Late Wisconsinan) Laurentide glaciation occurs at the surface, except where it is overlain by postglacial sediments. The advance that deposited this till was the most extensive in the study area, and the only advance definitively recognized in western Alberta south of the study area. Late Wisconsinan Cordilleran till has not been found in the study area, but Cordilleran and Laurentide ice may have coalesced briefly during the last glaciation. Support for this supposition is provided by the inferred deflection of Laurentide flutings to the southeast by Cordilleran ice. The earliest Laurentide advance may have been the least extensive of the three Laurentide events recognized in the study area. Erratics attributed to this advance occur only east of the Halfway River – Beatton River drainage divide.

scholarly journals Oil and gas well drilling technology based on the system approaches and the results of application

2021 ◽  
Vol 1064 (1) ◽  
pp. 012059
Author(s):  
R R Gazizov ◽  
A P Chizhov ◽  
V E Andreev ◽  
A V Chibisov ◽  
V V Mukhametshin ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Gas Well ◽  
Well Drilling ◽  
Drilling Technology ◽  
System Approaches

scholarly journals Gel Pills for Downhole Pressure Control during Oil and Gas Well Drilling

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6318
Author(s):  
Mahmoud Khalifeh ◽  
Larisa Penkala ◽  
Arild Saasen ◽  
Bodil Aase ◽  
Tor Henry Omland ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Oil And Gas ◽  
Drilling Fluid ◽  
Solid Material ◽  
Static Condition ◽  
Pressure Control ◽  
Gas Well ◽  
Well Drilling ◽  
Geothermal Wells ◽  
Mitigation Action

During drilling of petroleum or geothermal wells, unforeseen circumstances occasionally happen that require suspension of the operation. When the drilling fluid is left in a static condition, solid material like barite may settle out of the fluid. Consequently, the induced hydrostatic pressure that the fluid exerts onto the formation will be reduced, possibly leading to collapse of the borehole or influx of liquid or gas. A possible mitigation action is placement of a gel pill. This gel pill should preferably be able to let settled barite rest on top of it and still transmit the hydrostatic pressure to the well bottom. A bentonite-based gel pill is developed, preventing flow of higher density drilling fluid placed above it to bypass the gel pill. Its rheological behavior was characterized prior to functional testing. The designed gel pill develops sufficient gel structure to accommodate the settled barite. The performance of the gel was tested at vertical and 40° inclination from vertical. Both conventional settling and the Boycott effect were observed. The gel pill provided its intended functionality while barite was settling out of the drilling fluid on top of this gel pill. The barite was then resting on top of the gel pill. It is demonstrated that a purely viscous pill should not be used for separating a high density fluid from a lighter fluid underneath. However, a bentonite or laponite gel pill can be placed into a well for temporary prevention of such intermixing.

Analysis of the Pressure Response of Kick Control in MPD

2014 ◽  
Vol 997 ◽  
pp. 713-716
Author(s):  
Pu Liu ◽  
Hu Yin ◽  
Tian Xiang Wang ◽  
Meng Han Si
Keyword(s):  
Oil And Gas ◽  
Fluid Pressure ◽  
Pressure Response ◽  
Control Technology ◽  
Gas Well ◽  
Well Drilling ◽  
Well Control ◽  
Overflow Control ◽  
And Control ◽  
Conventional Drilling

With narrow Density Windows wells and high pressure oil and gas well drilling growing in number, the kick risks becoming increasingly prominent and higher requirements for well control technology being needed, the manage pressure drilling (MPD) technology is used more and more widely. The problems like how to effectively find gas overflowand how to effectively control the overflow in the MPD must be solved.Well must be shuted timely in conventional drilling when overflow happens.The special characteristics of overflow control equipment determines the diversity and effectiveness of its overflow monitoring means in MPD, and the overflow is found more effectively and timely than conventional drilling. Well control risk will increase sharply if kick cannot be timely and effectively identified and controled when overflow occurs. MPD can quickly adjust the wellhead back pressure and inhibit the formation fluid further invasion. Therefore, combining with MPD process and the fluid pressure parameters, the article establishs process of kick recognition and kick control, analyses of the process and analyzes and evaluates the pressure response in process of kick control.MPD can better control the bottom hole pressure in well control situation, ensuring drilling safety. The process of kick recognition and control is of great significance to promote the development and application of kick control technology in MPD.

Achieving Efficiency in Environmental Assessment Through Focused Selection of Valued Components

2014 ◽  
Author(s):  
Ward Prystay ◽  
Andrea Pomeroy ◽  
Sandra Webster
Keyword(s):  
British Columbia ◽  
First Nations ◽  
Environmental Assessment ◽  
Local Governments ◽  
Oil And Gas ◽  
Assessment Process ◽  
Environmental Assessments ◽  
Baseline Information ◽  
The Government ◽  
Selection Of

Some of the largest oil and gas projects in Canada are currently being proposed in British Columbia. Establishing a fulsome and scientifically and socially defensible scope for environmental assessments in the oil and gas sector is a serious challenge for government and proponents. The approach taken by the federal National Energy Board to scope effects assessments on pipelines is quite different than the approach taken by the British Columbia Environmental Assessment Office on other types of oil and gas projects. The NEB has published guidelines for scoping and conducting environmental and socio-economic assessments within its Filing Manual (National Energy Board [NEB] 2014). This manual sets out the expectations for scoping, baseline information, and effects assessments to be submitted as part of approval applications. Proponents are expected to provide all information necessary to meet the guidelines. In British Columbia, the environmental assessment process is dictated by the British Columbia Environmental Assessment Act and includes a negotiated terms of reference for the assessment, called the Application Information Requirements (AIR). The approach to selection of valued components is guided by provincial guidelines (EAO, 2013). The first draft of the AIR is prepared by the proponent and is then amended to address matters raised by federal and provincial agencies, local governments, and representatives of potentially affected First Nations. Through two to three revisions, the scope of assessment is jointly established and then formally issued by the government. While there are valid reasons for the differing federal and provincial approaches to scoping environmental assessments, each of these processes create risks for proponents in terms of project timelines and costs for preparing the environmental assessment. More specifically, the use of generic and negotiated guidelines can result in a number of issues including: • A scope of assessment that is broader than necessary to understand the potential for significant adverse effects • Inclusion of issues that are “near and dear” to a specific regulator or community but has no direct relationship to the effects of the project itself • Selection of valued components that do not allow for defensible quantification of effects or use of directly relevant significance thresholds • Selection of valued components that are only of indirect concern as opposed to focusing the assessment on the true concern. • Double counting of environmental effects • Risks in assessing cumulative effects This paper discusses where and how these risks occur, and provides examples from recent and current environmental assessments for pipelines and facilities in British Columbia. Opportunities to manage the scope of assessment while providing a fulsome, efficient, effective and scientifically/socially defensible assessment are discussed.

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