THE IMPACT OF BED- TO GEOBODY-ARCHITECTURE ON RESERVOIR PREDICTION: HYPOTHESIS-BASED MODELING IN A DEEP-WATER DEPOSITIONAL ENVIRONMENT

2019 ◽  
Author(s):  
Lisa Stright ◽  
Keyword(s):  
Deep Water ◽  
Depositional Environment ◽  
Reservoir Prediction ◽  
The Impact

scholarly journals Architectural Diversity of Submarine Lobate Deposits

2021 ◽  
Vol 9 ◽  
Author(s):  
Tim R. McHargue ◽  
David M. Hodgson ◽  
Eitan Shelef
Keyword(s):  
Turbulent Flows ◽  
Deep Water ◽  
Relative Size ◽  
Transport Pathway ◽  
Branching Points ◽  
Channel Patterns ◽  
The Impact ◽  
Source Materials ◽  
Permeability Structure ◽  
Distributary Channel

Lobate deposits in deep-water settings are diverse in their depositional architecture but this diversity is under-represented in the literature. Diverse architectures result from multiple factors including source material, basin margin physiography, transport pathway, and depositional setting. In this contribution, we emphasize the impact of differing source materials related to differing delivery mechanisms and their influence on architecture, which is an important consideration in source-to-sink studies. Three well imaged subsurface lobate deposits are described that display three markedly different morphologies. All three lobate examples, two from intraslope settings offshore Nigeria and one from a basin-floor setting offshore Indonesia, are buried by less than 150 m of muddy sediment and are imaged with high resolution 3D reflection seismic data of similar quality and resolution. Distinctively different distributary channel patterns are present in two of the examples, and no comparable distributaries are imaged in a third example. Distributary channels are emphasized because they are objectively recognized and because they often represent elements of elevated fluid content within buried lobate deposits and thus influence permeability structure. We speculate that the different distributary channel patterns documented here resulted from different processes linked to source materials: 1) a lobate deposit that is pervasively channelized by many distributaries that have branched at numerous points is interpreted to result from comparatively mud-rich, stratified, turbulent flows; 2) an absence of distributaries in a lobate deposit is interpreted to result from collapse of mud-poor, turbulent flows remobilized from littoral drift; and 3) a lobate deposit with only a few, long, straight distributaries with few branching points is interpreted to be dominated by highly viscous flows (i.e., debris flows). We propose a conceptual model that illustrates the relationship between the proportion of mud in contributing flows and the relative size and runout distance of lobate deposits. We conclude that reconciling 3D seismic morphologies with outcrop observations of channels, scours, and amalgamation zones, and simple application of hierarchical schemes, is problematic. Furthermore, when characterizing unconfined deep-water deposits in the subsurface, multiple models with significant differences in predicted permeability structure should be considered.

scholarly journals Experimental Study of Drop Impact on Deep-Water Surface in the Presence of Wind

2018 ◽  
Vol 48 (2) ◽  
pp. 329-341 ◽  
Author(s):  
Xinan Liu
Keyword(s):  
Deep Water ◽  
Water Surface ◽  
Water Drop ◽  
Threshold Value ◽  
Impact Angle ◽  
Drop Impact ◽  
Wind Speeds ◽  
Secondary Droplets ◽  
Low Wind Speeds ◽  
The Impact

AbstractThe effects of wind on the impact of a single water drop on a deep-water surface are studied experimentally in a wind tunnel. Experiments are performed by varying impacting drop diameters, ranging from 2.5 to 4.1 mm and wind speeds up to 6.7 m s−1. The sequence of splashing events that occurred during drop impacts is recorded with a backlit, cinematic shadowgraph technique. The experimental results show that for low wind speeds, an asymmetrical crown forms on the leeward of the periphery of the colliding region after the drop hits the water surface, while a wave swell forms on the windward. Secondary droplets are generated from the crown rim. For high wind speeds with large drop diameters, ligaments are generated from the crown rim on the leeward of the drop impact site. The ligaments grow, coalesce, and fragment into secondary droplets. It is found that both the drag force and surface tension play important roles in the evolution process of the ligaments. The nondimensional K number (K = WeOh−0.4, where We is the Webber number and Oh is the Ohnesorge number) is used to describe the splashing-deposition limit of drop impact. The threshold value of this K number changes with the wind velocity and/or drop impact angle.

Effect of Flexible Joint Modelling Method on Deep Water Catenary Riser Hang-Off Fatigue Response

2019 ◽  
Author(s):  
Guanyu Hu ◽  
Chaojun Huang ◽  
Fengjie Yin ◽  
Mark Cerkovnik ◽  
Guangqiang Yang
Keyword(s):  
Deep Water ◽  
Joint Stiffness ◽  
Fatigue Performance ◽  
Fatigue Load ◽  
Flexible Joint ◽  
Cyclic Bending ◽  
Modelling Method ◽  
The Impact ◽  
Nonlinear Curve ◽  
Modelling Methods

Abstract The Flexible joint is one of the most widely used hang-off systems for deep water catenary riser for its large rotation and load bearing capacity. The fatigue performance of riser hang-off region and fatigue load on the flexible joint highly depend on the rotational stiffness of the flexible joint. Thus, modelling the flexible joint stiffness to accurately simulate the behavior under cyclic bending cycles is critical in global riser fatigue analysis. The load-displacement relationship of a flexible joint typically follows a nonlinear curve, and it shows hysteresis behavior when subject to cyclic bending cycles. However, in current industry practice, the flexible joint stiffness is modelled either as a nonlinear curve or simplified as a fixed value. These simplified methods sometimes can lead to unconservative or over conservative results in riser design. Modelling the flexible joint stiffness in an accurate approach becomes more important especially when the riser fatigue is critical at the hang-off region. In addition, the design of flexible joint will also be impacted by the fatigue load extracted from global fatigue analysis, which is also largely affected by the flexible joint stiffness modelling method. Thus, modelling a flexible joint by accounting for the nonlinear hysteretic stiffness is recommended. This paper compares the different modelling methodologies of the flexible joint for catenary riser hang-off and presents the impact on fatigue performance considering hysteretic behavior. This study considers the effects of wave amplitude and hosting vessel offset. A case study is also presented on the application of all the modelling methods on fatigue performance of an SCR in the Gulf of Mexico. The fatigue behavior is compared for the different modelling methods considering long term wave motion and platform offsets. The impact on the results from different types of hosting platform is also discussed.

Strength and Fatigue Performance of Steel Lazy Wave Risers With Change in Configuration Parameters

2019 ◽  
Author(s):  
Mayank Lal ◽  
Feng Wang ◽  
Xiaohua Lu ◽  
Abhilash Sebastian
Keyword(s):  
Deep Water ◽  
Parametric Study ◽  
Fatigue Performance ◽  
Design Criteria ◽  
Cost Assessment ◽  
Fatigue Design ◽  
Design Variables ◽  
Steel Catenary Risers ◽  
Normative Cost ◽  
The Impact

Abstract Steel Lazy wave risers are being increasingly used for deep water applications due to better strength and fatigue performance in the touchdown zone compared to steel catenary risers. Several parameters govern the design of steel lazy wave risers including the length of the catenary from hang-off to start of buoyancy section and the length of the buoyancy section. In this paper, a parametric study is performed to investigate the trends in strength and fatigue performance of steel lazy wave risers with change in configuration parameters. A normative cost assessment is also performed to show the impact of these design variables on overall cost of the system. Dynamic analysis is performed to check the change in strength and fatigue performance of steel lazy wave risers as the configuration parameters are changed. The results from the parametric study will assist in designing steel lazy wave risers which satisfy the strength and fatigue design criteria.

A global survey of the impact on acoustic propagation of deep water warm core ocean eddies

1994 ◽  
Vol 95 (5) ◽  
pp. 2880-2880 ◽  
Author(s):  
David G. Browning ◽  
Raymond J. Christian ◽  
Linda S. Petitpas
Keyword(s):  
Deep Water ◽  
Acoustic Propagation ◽  
Ocean Eddies ◽  
Global Survey ◽  
Warm Core ◽  
The Impact

scholarly journals The impact of African aridity on the isotopic signature of Atlantic deep waters across the Middle Pleistocene Transition

2012 ◽  
Vol 77 (1) ◽  
pp. 182-191 ◽  
Author(s):  
Bruno Malaizé ◽  
Elsa Jullien ◽  
Amandine Tisserand ◽  
Charlotte Skonieczny ◽  
E. Francis Grousset ◽  
...  
Keyword(s):  
Deep Water ◽  
Benthic Foraminifera ◽  
Environmental Changes ◽  
Phase Relationship ◽  
Isotopic Signature ◽  
Middle Pleistocene ◽  
Time Interval ◽  
Deep Waters ◽  
Time Period ◽  
The Impact

A high resolution analysis of benthic foraminifera as well as of aeolian terrigenous proxies extracted from a 37 m-long marine core located off the Mauritanian margin spanning the last ~ 1.2 Ma, documents the possible link between major continental environmental changes with a shift in the isotopic signature of deep waters around 1.0–0.9 Ma, within the so-called Mid-Pleistocene Transition (MPT) time period. The increase in the oxygen isotopic composition of deep waters, as seen through the benthic foraminifera δ18O values, is consistent with the growth of larger ice sheets known to have occurred during this transition. Deep-water mass δ13C changes, also estimated from benthic foraminifera, show a strong depletion for the same time interval. This drastic change in δ13C values is concomitant with a worldwide 0.3‰ decrease observed in the major deep oceanic waters for the MPT time period. The phase relationship between aeolian terrigeneous signal increase and this δ13C decrease in our record, as well as in other paleorecords, supports the hypothesis of a global aridification amongst others processes to explain the deep-water masses isotopic signature changes during the MPT. In any case, the isotopic shifts imply major changes in the end-member δ18O and δ13C values of deep waters.

scholarly journals Escape ring selectivity, bycatch, and discard survivability in the New England fishery for deep-water red crab, Chaceon quinquedens

2007 ◽  
Vol 64 (8) ◽  
pp. 1579-1586 ◽  
Author(s):  
S. M. L. Tallack
Keyword(s):  
New England ◽  
Deep Water ◽  
Carapace Width ◽  
Discard Mortality ◽  
Male Crab ◽  
Gear Selectivity ◽  
Stock Assessments ◽  
Trap Fishery ◽  
The Impact ◽  
Control Trap

Abstract Tallack, S. M. L. 2007. Escape ring selectivity, bycatch, and discard survivability in the New England fishery for deep-water red crab, Chaceon quinquedens. – ICES Journal of Marine Science, 64: 1579–1586. The trap fishery for red crab, Chaceon quinquedens, occurs at depths of 600–800 m along the continental slope of New England. The target product is a male crab with a carapace width of ∼105 mm or greater. Selectivity was tested at two discrete depths (600 and 800 m), for four different escape ring scenarios: control trap with no escape rings, and escape rings with internal diameters of 9, 10, and 11 cm. Proportions of non-marketable C. quinquedens were large (71–100%) at both depths for all traps, but were smallest in traps with escape rings. Discard mortality was estimated at ∼5% through caging experiments across three haul frequency conditions (every 24 h, every 4 d, and after 8 d), which represented the likely reality of multiple recaptures during a commercial trip. The impact of discarding techniques (low and high impact) was also assessed. If discard proportion estimates of >71% are realistic, and if an estimated ∼5% of these discards die, the recommendation must be made for fishery participants to improve gear selectivity, and thereby to minimize discard mortality rates. On the management side, stock assessments will be more accurate if estimates of discard mortality are incorporated.

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