scholarly journals Vertical effective stress and temperature as controls of quartz cementation in sandstones: Evidence from North Sea Fulmar and Gulf of Mexico Wilcox sandstones

2020 ◽  
Vol 115 ◽  
pp. 104289
Author(s):  
Olakunle J. Oye ◽  
Andrew C. Aplin ◽  
Stuart J. Jones ◽  
Jon G. Gluyas ◽  
Leon Bowen ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
North Sea ◽  
Effective Stress ◽  
Vertical Effective Stress

scholarly journals Empirical relationships of shear wave velocity, SPT-N value and vertical effective stress for different soils in Mashhad, Iran

2015 ◽  
Vol 58 (3) ◽  
Author(s):  
Azam Ghazi ◽  
Naser Hafezi Moghadas ◽  
Hosein Sadeghi ◽  
Mohamad Ghafoori ◽  
Gholam Reza Lashkaripur
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Effective Stress ◽  
Shear Wave Velocity ◽  
Response Analysis ◽  
Empirical Relationships ◽  
Data Set ◽  
Fine Grain ◽  
Geophysical Investigations ◽  
Vertical Effective Stress

<p>Shear wave velocity, V<sub>s</sub>, is one of the important input parameters in seismic response analysis of the ground. Various methods have been examined to measure the soil V<sub>s</sub> directly. Direct measurement of V<sub>s</sub> is time consuming and costly, therefore many researchers have been trying to update empirical relationships between V<sub>s</sub> and other geotechnical properties of soils such as SPT Blow count, SPT-N. In this study the existence of a statistical relationship between V<sub>s</sub>, SPT-N<sub>60 </sub>and vertical effective stress, signa<sub>nu</sub>´, is investigated. Data set we used in this study was gathered from geotechnical and geophysical investigations reports. The data have been extracted from more than 130 numbers of geotechnical boreholes from different parts of Mashhad city. In each borehole the V<sub>s</sub> has been measured by downhole method at two meter intervals. The SPT test also has performed at the same depth. Finally relationships were developed by regression analysis for gravels, sands and fine grain soils. The proposed relationships indicate that V<sub>s</sub> is strongly dependent on signa<sub>nu</sub>´. In this paper the effect of fine percent also is considered on the V<sub>s</sub> estimation.</p>

Technical and Economic Evaluation of a Gulf of Mexico PlatForm for Reuse in the North Sea

1998 ◽  
Author(s):  
S. DeFranco ◽  
J. Gebara ◽  
P. O&apos;Connor ◽  
W. Hamilton ◽  
F. Puskar ◽  
...  
Keyword(s):  
Economic Evaluation ◽  
Gulf Of Mexico ◽  
North Sea ◽  
The North ◽  
The North Sea

THE INFLUENCE OF COMPOSITION, DIAGENESIS AND COMPACTION ON SEAL CAPACITY IN THE MUDERONG SHALE, CARNARVON BASIN

2004 ◽  
Vol 44 (1) ◽  
pp. 201 ◽  
Author(s):  
G.E. Kovack ◽  
D.N. Dewhurst ◽  
M.D. Raven ◽  
J.G. Kaldi
Keyword(s):  
Effective Stress ◽  
Pore Geometry ◽  
Burial Depth ◽  
Threshold Pressure ◽  
Direct Influence ◽  
Different Depths ◽  
Northern Carnarvon Basin ◽  
Vertical Effective Stress ◽  
Mercury Injection Capillary Pressure ◽  
Carnarvon Basin

The Muderong Shale blankets most of the northern Carnarvon Basin and is the top seal to over 90% of all commercial discoveries. This study examines the influence that vertical effective stress, mineralogy and diagenesis have on regional variations of seal capacity. Throughout the basin, threshold pressures (determined from Mercury Injection Capillary Pressure (MICP) analyses), range from less than 1,000 psi (equivalent to ~100 m gas column) up to 10,000 psi (~1,000 m gas column). Because the Muderong Shale varies in thickness (5 m to >900 m) and burial depth (~0.5–3.5 km), effective stresses and temperatures also vary. Effective stress and temperature significantly control pore geometry at different depths through compaction and diagenesis. The data from this study show that shale grain size has no direct influence over seal threshold pressure except that finer-grained Muderong Shale (36–45% particles 2.5 km) along the Northern Alpha Arch and Rankin Platform, total illite content is only moderate.

The underwater contractor: his role and development

1978 ◽  
Vol 290 (1366) ◽  
pp. 153-159
Keyword(s):  
Cost Effectiveness ◽  
Middle East ◽  
Gulf Of Mexico ◽  
North Sea ◽  
Water Depth ◽  
Equipment Maintenance ◽  
Surface Conditions ◽  
Additional Burden ◽  
Exploitation And Exploration ◽  
Maintenance And Inspection

Recovery of hydrocarbons from the seabed has a long history, particularly in the Gulf of Mexico and Middle East. Steps and processes required to extract oil from the seabed are essentially the same as those for recovery on land, but with the additional burden of bridging water depth. The transition to exploitation of North Sea discoveries brought problems not always fully appreciated, the most persistent of which is still the unpredictable and harsh weather and sea conditions. The rate of exploitation and exploration depended upon the work speed in the more favourable surface conditions. Experience and ingenuity have contributed greatly to reducing downtime. However, worldwide moves into greater depths and even less sheltered waters, stretch the suitability and cost-effectiveness of conventional structures and the techniques employed for seabed equipment maintenance and inspection. Consequently, the recently developed concepts for installation and servicing of engineering complexes on the seabed are providing one of the most significant steps towards the goal of year-round operations.

Variation of velocity with effective stress in chalk:null result from North Sea well data

2002 ◽  
Vol 19 (8) ◽  
pp. 921-927 ◽  
Author(s):  
M. Lubanzadio ◽  
N.R. Goulty ◽  
R.E. Swarbrick
Keyword(s):  
North Sea ◽  
Effective Stress ◽  
Well Data

scholarly journals Non-isothermal volume change behavior of saturated sand subjected to minimal vertical effective stress

2020 ◽  
Vol 205 ◽  
pp. 09008
Author(s):  
Yize Pan ◽  
Alessandro F. Rotta Loria
Keyword(s):  
Effective Stress ◽  
Volume Change ◽  
Current Knowledge ◽  
Coarse Grained ◽  
Saturated Sand ◽  
Isothermal Conditions ◽  
Heating And Cooling ◽  
Change Behavior ◽  
Volume Change Behavior ◽  
Vertical Effective Stress

To date, the majority of the available studies on the volume change behavior of soils under non- isothermal conditions have focused on fine-grained soils. Only a limited number of investigations have been made available about coarse-grained soils despite their abundance in practice, with contradictory features. To enrich the current knowledge about the volume change behavior of coarse-grained soils under non-isothermal conditions, this investigation presents the results of oedometric tests with temperature control performed on saturated sand. The influence of relative density on the volume change behavior of the tested material under non-isothermal conditions is investigated under a minimal level of applied vertical effective stress. The results show an expansive volume change upon heating and contractive volume change upon cooling for all relative densities. The magnitude of the contraction is more significant than that of the expansion, leading to a residual contractive volume change after one cycle of heating and cooling. The results of this study enrich the current literature about the volume change behavior of coarse-grained soils under non-isothermal conditions. Such competence may be considered for applications at the interface of geomechanics and energy wherein temperature variations occur and characterize the response of coarse-grained soils.

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