The Application of Petrophysical Data to Improve Pore and Fracture Pressure Determination in North Sea Central Graben HPHT Wells

Ward, C.D.; Coghill, K.; Broussard, M.D.

doi:10.2523/28297-ms

Cited by 4 publications

(8 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Overpressure in the general North Sea Central Graben area has been the subject of many studies (e.g. Hunt 1990, Powley 1990, Ward et al 1994, Osborne and Swarbrick 1997, Dennis et al 2005. Powley (1990) recognized a similar three-fold subdivision for the southern Norwegian North Sea adjacent to the study area of this paper.…”

mentioning

confidence: 58%

Pressure variations in the northern part of the Danish Central Graben, North Sea

Vejbæk¹

2022

View full text Add to dashboard Cite

The overpressure variation in the Cenozoic to Jurassic succession in the northern part of the Danish Central Graben may broadly be divided into three major compartments: An upper hydrostatically pressured unit comprises the post-mid Miocene to recent succession down to ∼ 1200 m depth in the North and ∼ 700m in the South part of the Danish Central Graben. The second compartment comprises the mid-Miocene smectite rich clays down to and including the upper Cretaceous chalk. There, the Paleogene to Lower Miocene succession provides the seal. The third compartment constitutes the Jurassic succession with pressure above hydrostatic that may exceed twice that seen at the upper chalk level. Pressure levels can be estimated using Eaton's approach for the second compartment in agreement with pressure data. Modeling of the transient pressure development in the Cretaceous — mid-Miocene succession broadly complies with Eaton estimates and show main overpressure build-up to occur within the last 10 Ma. The overpressure in this succession may be mapped using methods that exploit correlations between fluid pressure and degree of consolidation, - while the Jurassic cannot. However, the lateral variation of the upper Jurassic overpressure correlates broadly with the maturity of the Upper Jurassic source rock allowing the pressure variation to be mapped.Thematic collection: This article is part of the Geopressure collection available at: https://www.lyellcollection.org/cc/geopressureSupplementary material:https://doi.org/10.6084/m9.figshare.c.5797068

show abstract

mentioning

confidence: 58%

Pressure variations in the northern part of the Danish Central Graben, North Sea

Vejbæk¹

2022

View full text Add to dashboard Cite

show abstract

“…In some basins there are multiple transition zones that may extend continuously across large parts of the basin (Hunt 1990;Ward et al 1994). The origin of these transition zones is not well understood, but may relate to basin-wide fluid controls linked to diagenetic reactions.…”

Section: Multiple Transition Zonesmentioning

confidence: 98%

“…The maximum increase in pressure with depth is therefore parallel to the lithostatic pressure gradient (Clayton & Hey 1994). Examples of pressure profiles with a transition zone parallel or subparallel to the estimated lithostatic gradient include parts of the Caspian Sea (data from Bredehoeft et al 1988 (Ward et al 1994). In each of the above examples, modern sedimentation rates are high and there is a predominance of fine-grained sediments.…”

Section: Disequilibrium Compactionmentioning

confidence: 99%

“…In each of the above examples, modern sedimentation rates are high and there is a predominance of fine-grained sediments. The top of the transition zone has been termed the 'Fluid Isolation Depth' (Ward et al 1994), and its depth is a function of the rate of sediment loading and the permeability of the rock. Continued constant rate of burial of rocks with the same sedimentary characteristics will result in maintenance of the fluid isolation depth at the same depth through time.…”

Section: Disequilibrium Compactionmentioning

confidence: 99%

See 1 more Smart Citation

The nature and diversity of pressure transition zones

Swarbrick

Osborne

1996

View full text Add to dashboard Cite

Pressure transition zones occur where the rate of pressure increase or decrease exceeds a fluid gradient. Transition zones are found between intervals of permeable rock and, in each case, fluid movement is impeded by a 'seal', which acts as a temporary barrier over geological time. The composite profile of pressure vs.depth is a function of three phenomena: (1) the mechanism responsible for abnormal pressure, (2) redistribution of pressure due to fluid movement during and after the mechanism is occurring, and (3) the lithological profile of the rock succession. Pressure profiles in some overpressured systems can reveal which of the mechanisms is causing the overpressure. Once overpressure has been created, pressure decay and transference away from the interval of generation can strongly influence the nature of transition zones. Transition zones are controlled in a fundamental way by the permeability of the rocks in which the abnormal pressure is found.

show abstract

“…Some authors suggest the transition from hydrostatic to overpressured conditions occurs within the chalk (e.g. Ward et al, 1994). Many published pressure profiles show the chalk as normally pressured or to be overpressured to the same magnitude throughout ( Fig.…”

Section: Introductionmentioning

confidence: 96%

Diagenetic characteristics of low permeability, non-reservoir chalks from the Central North Sea

Mallon

Swarbrick

2008

Marine and Petroleum Geology

View full text Add to dashboard Cite

The Application of Petrophysical Data to Improve Pore and Fracture Pressure Determination in North Sea Central Graben HPHT Wells

Cited by 4 publications

References 0 publications

Pressure variations in the northern part of the Danish Central Graben, North Sea

Pressure variations in the northern part of the Danish Central Graben, North Sea

The nature and diversity of pressure transition zones

Diagenetic characteristics of low permeability, non-reservoir chalks from the Central North Sea

Contact Info

Product

Resources

About