Natural gas in the Permian-Triassic Khuff Formation of Abu Dhabi contains variable amounts H2S. Gas souring occurred through thermochemical sulfate reduction anhydrite by hydrocarbon gases. Sour is observed only reservoirs hotter than a critical reaction temperature: 140°C. Petrographic examination core from wide depth range showed that reactant has been replaced calcite product samples deeper 4300 m. composition data show m contain large quantities H2S (i.e., >10%). At present-day...

Septarian carbonate concretions contain precipitated during progressive growth of the concretion and subsequent fracture-filling. As such, they have been used to track variations in δ13C δ18O pore waters diagenesis define diagenetic zones clastic rocks. However, value is dependent on precipitation temperature fluid from which it precipitated. Interpretations must assume one these parameters, both are highly variable through time settings. Carbonate clumped isotopes cement can provide...

ABSTRACT Thermochemical sulfate reduction (TSR) is the reaction between anhydrite and petroleum fluids at elevated temperatures to produce H2S calcite. In this study of dolomite-hosted hydrocarbon gas reservoirs in Permo-Triassic Khuff Formation, Abu Dhabi, a geochemically well constrained rock-gas system, we demonstrate for first time clear influence rock texture mineralogy on rate extent TSR reactions thus concentration phase. The controls accumulation were: kinetics. became significant as...

In the current debate on ability of oil emplacement to halt quartz cementation in sandstone reservoirs, this paper supports a "yes, it can" answer. Although we find some empirical data petroleum fluid inclusion abundances, quartz-depth trends) be inconclusive, have made progress by examining theoretical controls for three end-member scenarios. (1) Silica externally sourced via advection. Oil must because associated massive reduction relative permeability water. (2) supplied internally,...

Research Article| July 01, 1997 Sulfur cycle in buried evaporites R. H. Worden; Worden 1The School of Geosciences, The Queen's University, Belfast, Northern Ireland BT7 1NN, United Kingdom Search for other works by this author on: GSW Google Scholar P. C. Smalley; Smalley 2BP Exploration, Exploration Technology Centre, Sunbury and Engineering Chertsey Road, on Thames, Middlesex TW16 7LN, A. E. Fallick 3Isotope Geosciences Unit, Scottish University Reactor East Kilbride, Glasgow G75 0QF,...

Abstract The orthopyroxene‐clinopyroxene, garnet‐orthopyroxene and garnet‐clinopyroxene geothermometers, the garnet‐orthopyroxene‐plagioclase, garnet‐clinopyroxene‐plagioclase anorthite‐ferrosilite‐grossular‐almandine‐quartz geobarometers are applied to metabasites garnetplagioclase‐sillimanite‐quartz geobarometer is a metapelite from Proterozoic Arendal granulite terrain, Bamble sector, Norway. P–T conditions of metamorphism were 7.3 ± 0.5 kbar 800 60°C. This terrain shows regional...

Abstract Authigenic quartz cement is the most abundant form of diagenetic in clastic sedimentary rocks. Despite this, there are many unknowns relating to mechanisms growth and crystallography cement. The key focus this paper investigate further issues mechanisms, using shallowly buried Oligo-Miocene Fontainebleau sandstone, France, as a case study. We address following points: (1) authigenic overgrowths really crystallographic continuity with their substrate grains? (2) What...

Saline aquifers possess significant storage capacity for CO2, offering a potential resource mitigating anthropogenic climate change due to CO2 emissions. However, identifying suitable sites across regions that may be several tens or hundreds kmacross can extremely time consuming both computationally and in terms of human resources. This study introduces Dynamic Common Risk Segment (D-CRS) workflow efficiently screen large-scale saline rapidly pinpoint promising locations further detailed...

Research Article| October 01, 2001 Evidence for reduced quartz-cementation rates in oil-filled sandstones Ann M.E. Marchand; Marchand 1Department of Geology and Geophysics, University Edinburgh, West Mains Road, Edinburgh EH9 3JW, UK Search other works by this author on: GSW Google Scholar R. Stuart Haszeldine; Haszeldine P. Craig Smalley; Smalley 2BP Centre, Sunbury-on-Thames, Middlesex TW16 7LN, Calum I. Macaulay; Macaulay 3Department Anthony E. Fallick 4Scottish Universities Environmental...

Research Article| May 01, 1994 Seawater Sr isotope variations through time: A procedure for constructing a reference curve to date and correlate marine sedimentary rocks P. C. Smalley; Smalley 1British Petroleum, Engineering Centre, Chertsey Road, Sunbury-on-Thames, Middlesex TW16 7LN, United Kingdom Search other works by this author on: GSW Google Scholar A. Higgins; Higgins R. J. Howarth; Howarth H. Nicholson; Nicholson E. Jones; Jones 2Department of Geological Sciences, University...

Oil emplacement retarded the rate of quartz cementation in Brae Formation deep-water sandstone reservoirs Miller and Kingfisher fields (United Kingdom North Sea), thus preserving porosity despite rocks' being buried to depths 4 km 120 degreesC. Quartz precipitation rates were reduced by at least two orders magnitude oil legs relative water legs. Important contrasts cement abundances porosities have emerged between where filled with hydrocarbons gradually over a prolonged period time (>15...

Summary Fluid composition is a valuable addition to the battery of "static" data available during reservoir appraisal that can be used predict dynamic behavior later in field life. This because fluid are not truly static; natural mixing process occurs over long (geologic) time scale. Oil compositional differences, especially those parallel changes density, should mixed rapidly by convection; their preservation indicates barriers flow. Water variations, now measurable on conventional core...

Summary Reservoir compartmentalization (vertical and lateral) is often a major uncertainty at the field appraisal stage, impacting important investment decisions. Unfortunately, most definitive data (dynamic production data) are not usually available so early in life. This paper illustrates how indications of can be achieved by integrating various types conventional novel data. Using an example from Ross oilfield, U.K. Continental Shelf (UKCS), we demonstrate integration oil compositional...

Abstract A total of 236 individual water analyses from over 70 fields in the North Sea and Norwegian Haltenbanken area were provided by field operators or collated literature (Table 4.1). All data supplied as representative formation for that field. Most routine ten ion with accompanying on sample type, resistivity reservoir conditions. Where these not but available other sources, they have been added to original contribution. Previously published also included where available. Minor ions,...

An improved analytic solution is presented that describes the dissipation of abnormal pressures via Darcy flow out a compartment formed high-permeability rock capped top and bottom by lower permeability rock. The tends to solutions previous workers in limit (1) thick thin barrier (2) compartment. importance including fluid compressibility when analyzing hydrocarbon reservoirs demonstrated. Previous this field have only included effect bulk neglected compressibility.The applied pressure...

We present a model that explains the patterns of sandstone burial diagenesis in certain oil reservoirs, which petroleum migration and cementation were synchronous. The coincidence these two processes controls chemistry distribution major cement phases across field, turn reservoir quality, causing rapid decline porosity permeability with depth. Such poroperm deterioration is observed many North Sea oilfields; we highlight Magnus Sandstone Member Oilfield, northern as type example such...