ODP Leg 150, Hole 903A - Well Logging Data
Gregory S. MountainKenneth G. MillerPeter BlumPer-Gunnar AlmMarie‐Pierre AubryLloyd H. BurckleBeth A. ChristensenJohn S. ComptonJohn E. DamuthJean-Frangois DeconinckLaurent de VerteuilCraig S. FulthorpeStefan GartnerGilles GuérinStephen P. HesselboBryce HoppieMiriam KatzNobuhiro KotakeJuan M. LorenzoStuart McCrackenCecilia M. McHughWendy C. QuayleYoshiki SaitoScott W. SnyderWarner G. ten KateMichael UrbatMickey C. Van FossenAdam Vecsei
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Abstract:
Logging data are measurements of physical properties of the formation surrounding a borehole, acquired in situ after completion of coring (wireline logging) or during drilling (Logging-While-Drilling, LWD). The range of data (resistivity, gamma radiation, velocity, density, borehole images,…) in any hole depends on the scientific objectives and operational constraints.Fluvial fans represent one of the dominant sedimentary systems at the active margins of non-marine foreland basins. The Puig-reig anticline at the north-eastern margin of the Ebro Foreland Basin (SE Pyrenees, Spain) exposes continuous outcrops of Late Eocene-Early Oligocene fluvial deposits, from proximal to medial fluvial fan environments. The proximal deposits are found in the north limb of the anticline, especially in the northwest zone. These deposits are characterised by conglomerates with minor interbedded sandstones, with thick and wide sheet-like geometries with unscoured or variably scoured basal surfaces. These are interpreted to be the deposits of unconfined flash floods and wide-shallow channel streams. The medial deposits, covering the rest of the anticline, consist of interbedded conglomerates, sandstones and claystones. These are interpreted to have been deposited from braided to meandering channel streams and overbank areas. Distal deposits are found towards the south, beyond the anticline, and are characterised by sandstone and clay deposits of terminal lobes and lacustrine deltas. This study assesses the impact of the primary depositional characteristics, diagenesis and deformation of the most heterolithic portion of the system, with implications for increasing our understanding of folded fluvial reservoirs. Diagenetic processes, mainly mechanical compaction and calcite cementation, resulted in overall low intergranular porosity, with limited relatively high porosity developed in sandstone lithofacies in the medial deposits. Deformation associated with thrusting and fold growth resulted in the formation of abundant fractures, with relatively high fracture intensities observed in sandstone lithofacies in the anticline crest. This study shows that post-depositional processes can both improve and diminish the reservoir potential of basin proximal fluvial deposits, through the development of fracture networks and by compaction-cementation. The comparison of the Puig-reig anticline with other similar settings worldwide indicates that foreland basin margin locations may be potential areas for effective reservoirs, even in the case of low intergranular porosity.
Anticline
Arenite
Syncline
Outcrop
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Metamorphic core complex
Lineation
Massif
Detachment fault
Transpression
Mylonite
Extensional tectonics
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Pennsylvanian foreland deformation associated with the Ouachita orogene reactivated a west-northwest-east-southeast Cambrian basement trend, the southern Oklahoma aulacogen, to form the Wichita uplift, southwest Oklahoma. The 30-km-wide subsurface Frontal fault zone separates the uplift from the Anadarko basin to the north. Horizontal shortening across this fault zone is estimated at 7-15 km (20-40%), vertical displacement totals 9-10 km from the uplift to the basin. Folds are mapped on an interformational scale within the Frontal fault zone, and on an intraformational scale (Cambro-Ordovician Arbuckle Group) in the Slick Hills, southwest Oklahoma. Additional shortening occurred along southwest dipping mountain flank thrusts and on bedding plane thrusts, respectively. Hanging wall blocks of major faults contain the shallow dipping limb and anticlinal hinge zone of the interformational scale folds. Oil and gas production is generally restricted to these anticlinal crests within Paleozoic rocks. Deep wells (> 6000 m) that have penetrated footwall imbricates of the mountain flank thrusts have drilled through steep-overturned beds and tight recumbent folds before passing through faults into a normal stratigraphic sequence. Basement thrust loading of the southern margin of the Anadarko basin controlled the trend (west-northwest-east-southeast) of the axis of maximum deposition within the basin during the Pennsylvanian.
Basement
Thrust fault
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Timber is harvested in the United States by thousands of independent logging businesses. Fully mechanized, whole-tree harvesting systems are the most common and most productive systems in most states, although chainsaw systems persist in mountainous terrain and cut-to-length systems are common in the Lake States. Southern loggers are most productive, with many logging businesses producing more than 70,000 tons yr-1 while loggers in other regions average <30,000 tons yr-1. Both the number of logging workers and logging businesses declined by 2% yr-1 in 1990–2016. However, despite consolidation, most studies report adequate or excess logging capacity. The logging sector faces a number of challenges, such as the need to recruit new business owners when the current generation retires, declining markets in some areas, and reduced working days per year. However, the logging sector has proven resilient and innovative over the years with significant improvements in productivity and environmental performance.
Consolidation
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Accretionary wedge
Anticline
Forearc
Mass wasting
Thrust fault
Seafloor Spreading
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Décollement
Accretionary wedge
Thrust fault
Trough (economics)
Anticline
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Selective logging is one of the most common forms of forest use in the tropics. Although the effects of selective logging on biodiversity have been widely studied, there is little agreement on the relationship between life-history traits and tolerance to logging. In this study, we assessed how species traits and logging practices combine to determine species responses to selective logging, based on over 4000 observations of the responses of nearly 1000 bird species to selective logging across the tropics. Our analysis shows that species traits, such as feeding group and body mass, and logging practices, such as time since logging and logging intensity, interact to influence a species' response to logging. Frugivores and insectivores were most adversely affected by logging and declined further with increasing logging intensity. Nectarivores and granivores responded positively to selective logging for the first two decades, after which their abundances decrease below pre-logging levels. Larger species of omnivores and granivores responded more positively to selective logging than smaller species from either feeding group, whereas this effect of body size was reversed for carnivores, herbivores, frugivores and insectivores. Most importantly, species most negatively impacted by selective logging had not recovered approximately 40 years after logging cessation. We conclude that selective timber harvest has the potential to cause large and long-lasting changes in avian biodiversity. However, our results suggest that the impacts can be mitigated to a certain extent through specific forest management strategies such as lengthening the rotation cycle and implementing reduced impact logging.
Frugivore
Omnivore
Insectivore
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Traditional timber harvesting methods can result in serious impacts on vegetation structures, soil properties, and biodiversity in forested areas. Helicopter logging provides important advantages of implementing environmentally friendly harvesting techniques. However, the cost of helicopter logging can be much higher than that of ground-based logging due to high equipment costs, maintenance costs, the cost of flight crew, and fuel costs. Thus, the helicopter logging operation should be carefully planned to implement cost effective and environmentally friendly logging operations. In this study, the stages of helicopter logging and operational factors were first described, and then the operation cost, environmental concerns, and safety practices in helicopter logging were discussed. It can be concluded that the helicopter logging can be effectively used for extraction of timbers especially from environmentally sensitive areas where road construction and logging operations are restricted. In fact, helicopter logging may be the only option to solve timber extraction problems in difficult terrains with steep slope.
Environmentally Friendly
Salvage logging
Felling
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Sequence (biology)
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The well logging and mud logging are intertwined each other.It is very important to analyze the logging data and its response characteristic of the reservoir.The relationship of the four properties was analyzed by use of the lithologic analysis data and logging data,and the change characteristic of the logging curve was found.The displaying feature of the cutting logging,geochemical logging and gas logging were anlyzed,which provided reliable evidences to the qualitative and quantitative interpretation.
Data logger
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