bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regional diagenetic controls on reservoir properties in the Millom accumulation: implications for field development
Authors: Cowan Greig , Bradney Joanna 
Published: April 2008

Abstract

The Millom accumulation comprises two dip-closed culminations situated down-flank of the 1 TCF North Morecambe Field. The depositional environments encountered in the Millom area are similar to those in the North Morecambe area and they share a common depositional layering. However, porosity and permeability are low compared to the Morecambe Fields. Although the presence of permeability reducing platy illite throughout the reservoir can explain the reduced permeabilities in the area, it does not account for the reduced porosity. The abundance of mineral cements (quartz and carbonates) increases rapidly away from the crest of the North Morecambe structure, down-dip towards the Millom area. The migration history of fluids outwards from the deeper parts of the basin is preserved by the cement distributions observed in the Morecambe-Millom area. Porosity in North Morecambe is preserved by an early hydrocarbon charge. The Millom structure had not formed during early hydrocarbon migration and was exposed to mineralizing fluids moving from the Keys Basin to the north. Both structures were filled with the present gas charge during late Cretaceous/early Tertiary gas migration. Poor reservoir properties, especially
K
v
, renders Millom unsuitable for development by horizontal wells.
The Lennox oil and gas Field
Authors: Haig D. B. , Pickering S. C. , Probert R. 
Published: April 2008

Abstract
The Lennox oil and gas Field is located in Block 110/15 of the East Irish Sea, approximately 10 km west of Southport, Lancashire. The field was discovered in 1992 with well 110/15-6 drilled by the P791 BHP group. The Lennox structure is a rollover anticline in Permo-Triassic sediments formed in the hanging wall of the Formby Point Fault. The reservoir comprises the Triassic Sherwood Sandstone Group, and is characterized by excellent permeability aeolian and fluvial sandstones. The structure is sealed by the overlying shales and evaporites of the Mercia Mudstone Group. To date four wells have been drilled on the Lennox Field and have delineated a free gas cap in communication with a constant thickness oil rim. The hydrocarbons have been sourced from Namurian Holywell shales and reflect complex migration into the Lennox structure. Reservoir studies indicate likely hydrocarbons-in-place of 463 BCF of gas and 218 MMBO of oil. Development approval for the Lennox Field was granted in 1993 with production due to commence in late 1995 from a series of horizontal oil producers. Gas produced during the early years will be recycled and re-injected into Lennox via a crestal gas well to help maximize the oil production. During the later years, production will switch to sales gas. Lennox will be developed as an integral part of BHP’s Liverpool Bay Development.
The origin of magnetic remanence components of Westphalian C to Stephanian C sediments, West Bohemia: a record of waning Variscan tectonism
Authors: Krs Miroslav , Pešek Jiří , Pruner Petr , Skoček Vladimír , Slepičková Jana 
Published: April 2008

Abstract
Petromagnetic and magnetomineralogical investigations of Westphalian C to Stephanian C rocks from the Central and Western Bohemian Late Palaeozoic Basins were undertaken to determine the origin of magnetic remanence components and of ferrimagnetic minerals — carriers of respective remanence components in a variety of rock types including tuffs, tuffites, siltstones, sandstones, grey and red claystones. Multi-component analysis allowed the separation of remanence components and a selection of petromagnetic and/or magnetomineralogical methods were used to determine the ferrimagnetic minerals. Magnetite was found to be the principal carrier of Variscan remanence components in most non-red-coloured rocks and haematite in red claystones originated during diagenesis in the Carboniferous period. In several samples, haematite, goethite and other Fe-oxides were found to result from recent weathering. In some samples, the Variscan remanence components were separated at relatively low temperatures, from about 150°C onwards. Variscan virtual pole positions have been derived from relatively small sets of samples. Nevertheless, they show that the rocks of the Westphalian C and D ages were more intensively deformed than those of the Stephanian, agreeing with an overall decrease in intensity of deformation in the final stages of the Variscan orogeny.
Turkish lignite deposits
Authors: İnaner H. , Nakoman E. 
Published: April 2008

Abstract

The distribution of lignite deposits in Turkey is such that in general the Eocene lignites are in northern Turkey, Oligocene lignites are in northwestern Turkey, Miocene lignites are in western Turkey, and Pliocene-Pleistocene lignites are in eastern Turkey. Only the Oligocene lignites are paralic deposits, the rest being formed in a limnic environment. Turkey has about 8.4 Gt of lignite reserves of which 3.9 Gt are the exploitable reserves. Most of the known lignite deposits in Turkey are of low calorific value and have high contents of ash, moisture and total sulphur. Almost 80% of the total reserves have calorific values below 2500 kcal kg
−1
. The lignites having low calorific values are generally consumed in power plants. The lignites having relatively high calorific values are exploited for domestic and industrial use in the country. The majority of Turkish lignite deposits are worked in open-pit mines, but there are also some underground operations.
Mössbauer spectroscopic investigation of low rank coal lithotypes
Authors: Kostova Irena , Markova Kalinka , Kuntchev Krasimir 
Published: April 2008

Abstract

Low rank coal lithotypes — xylain, humovitrain, semifusain, fusain and liptain sampled from the Maritsa Iztok coal basin (Bulgaria) have been examined by Mössbauer spectroscopy with no pre-concentration procedures. The results are used to identify three iron species in coal lithotypes and show that covalent iron (Fe
II
) related to pyrite, is the main iron species in xylain, while in humovitrain ferric iron is dominant. The total quantity of iron species in semifusain, fusain and liptain is about the same, but their distribution is different. Ferric iron dominates in all the three lithotypes. Ferrous iron, although present in smaller quantities, has a higher content in fusain than in semifusain. Our results illustrate the type of oxidation processes which formed the coal lithotypes. A transformation of Fe
2+
to Fe
3+
has occurred out as a result of differing oxidation processes. The intensity of that transformation increases during the destructive microbial oxidation and decreases during thermal oxidation and direct oxidation processes. The opposite transformation of ferric to ferrous iron has been achieved during both thermaloxidation and direct oxidation processes.
Aliphatic biological markers in Miocene Maritza-Iztok lignite, Bulgaria
Authors: Stefanova Maya , Magnier Caroline 
Published: April 2008

Abstract

Chromatographic separation and mass spectral studies of bitumens extracted from lithotypes (humovitrain, xylain, liptain and humoclarain) from the Miocene Maritza-Iztok lignite reveal the following: (1) A preponderance of the
α
-phyllocladane skeleton over the pimaranes/abietanes. The variety of tricyclic diterpanes confirms that the generation biota included gymnosperms; (2) The presence of dicotyledonous angiospermaes in the generation biota is indicated by the occurrence of widely distributed des-A-lupane structure; (3) The dominance of terpanes over steranes confirms the prevailing contribution of terrigenous input; (4) The preponderance of C

27
β

hopane and the presence of
ββ
hopanes indicates a low degree of thermal maturation.
Determination of different forms of sulphur in Yugoslav soft brown coals
Authors: Jankes G. , Cvetković O. , Glumičić T. 
Published: April 2008

Abstract
This paper presents the results of determination of different forms of sulphur in two Yugoslav soft brown coals, Kolubara (KOL) and Kostolac (KOST). The forms of sulphur were determined as sulphate, monosulphide, pyrite and organic sulphur containing compounds by step-wise oxidation with perchloric acid. The tests were carried out in an inert atmosphere in Bethge’s apparatus. KOL and Kost were quite different in sulphur content, KOL containing 0.71 wt% of sulphur and KOST 3.11 wt%, as well as in the distribution of each type of sulphur compound. Pyrite was dominant in KOST (1.89 wt%) and organic sulphur in KOL (0.47 wt%). The analytical method applied was simple and good reproductivity of results was shown. It was important that all types of sulphur were determined in a single and small sample, using the same oxidizing agent.
A well logging method for the determination of the sulphur content of coal seams by means of deep gammaspectrometry
Authors: Gregor Vít , Těžký Antonín 
Published: April 2008

Abstract
This contribution describes new spectral logging equipment developed at Geofyzika Brno which is designed to remotely determine the sulphur content in brown coal. The method is based on analyses of the prompt gamma ray spectrum induced in coal seams by a neutron source. Theoretical studies have demonstrated the possibility of using the 5.42 MeV peak of gamma radiation from sulphur. The measured spectrum is analysed in three independent parallel ways. The analyser is calibrated in the range from 0.6% to 10% of sulphur by weight. The lower detection limit is believed to be 0.3–0.5%, and the measurement sensitivity 0.1%.
Conversion of low rank coal into liquid fuels by direct hydrogenation
Authors: Aleksić B. R. , Ercegovac M. D. , Cvetković O. G. , Marković B. Ž. , Glumičić T. L. , Aleksić B. D. , Vitorvić D. K. 
Published: April 2008

Abstract

A study of low-rank coal conversion into liquid products by direct catalytic hydrogenation was undertaken. A soft brown coal from the ‘Tamnava’ field of the Kolubara mines characterized by a huminite reflectance of 0.27 ± 0.03% R
R
, ash content of 10.4 wt% (db), carbon content of 64.0 wt% (daf), and volatiles ca. 50 wt% (db), was submitted to liquefaction in a batch reactor. The effect of reaction parameters on both the yield and nature of liquefaction products was studied for temperatures ranging from 365 to 440°C, and pressure from 13.5 to 16.5 MPa, with process duration from 1 to 8 hours. The total coal conversion was high at all applied reaction conditions (84–93%, daf coal basis), pointing to a high reactivity of this coal. The yield of particular liquid products varied markedly depending on temperature and residence time. The yield of light-oil (
n
-heptane soluble products) increased and that of asphaltenes decreased by increasing the temperature and prolonging the residence time. Changes in petrographic composition of the coal were examined by microscopic analysis. At more severe reaction conditions the content of semicoke and coke increased. With the increase of temperature at mild conditions, the proportions of both the reacted coal and granular residue increased, while the cenospheres and mineral matter decreased. The nature of the changes observed in the organic and mineral components of the coal grains was used to correlate the degree of coal conversion with the experimental conditions.
The use of pulverized lignite/natural gas mixed fuels in the high-temperature process of a cement rotary kiln
Authors: Stanojević M. , Jankes G. , Kuburović M. , Stanojević M. , Blagojević P. 
Published: April 2008

Abstract
This paper presents the results of industrial tests of low grade lignite combustion in the 500 t/day wet-process rotary cement kiln. For the use of pulverized lignite, the following process characteristics are determined: combustion process parameters, flue gas properties, and the influence of coal ash properties on clinker quality. Industrial tests have shown that it is possible to substitute 50–80% of the natural gas with pulverized low-grade lignite, while the output of the kiln, specific heat consumption, and the quality of cement clinker remain unchanged.
Methane emission and its utilization from Ostrava-Karviná Collieries in the Upper Silesian coal basin, Czech Republic
Authors: Takla G. , Vavrušák Z. 
Published: April 2008

Abstract

The Ostrava-Karviná part (OKR) of the Upper Silesian coal basin is the most important hard coal basin in the Czech Republic. This basin extends over an area of 1600 km
2
. The Carboniferous basin fill contains 255 seams with a net coal thickness of 150m. The methane content in the coal is estimated between 4.4 to 20m
3
/t. In the OKR, about 120 million cubic meters per year of methane are produced by gas drainage plants from a number of collieries. The methane is used in local industries. Several measures have been taken to increase the methane extraction in active mines and in areas of closed collieries. Additionally, pilot projects for coalbed methane production have been started in virgin coal bearing areas with no previous coal production. The authors’ company is progressing with such a pilot project, with the first coalbed methane wells completed recently. Results to date are encouraging. All these activities are designed to increase the safety in mines, to reduce methane emission to the atmosphere, and to develop new sources of energy.
Cenozoic plate tectonic reconstructions of SE Asia
Authors: Hall Robert 
Published: April 2008

Abstract

A new plate tectonic model for the Tertiary is proposed, based on the integration of new palaeomagnetic data from east Indonesia recording Philippine Sea plate motion, recent revisions of the history of the South China Sea, and previously available geological and palaeomagnetic data from SE Asia. Early Neogene counter-clockwise rotation of Borneo is interpreted to have closed a proto-South China Sea suggesting a strike-slip boundary in NW Borneo before the Neogene. This rotation suggests that the West Philippine Sea, Celebes Sea and Makassar Strait formed a single basin which opened in the late Paleogene, and widened eastwards. At
c.
25 Ma a major collision, that of Australia with a Philippine Sea plate arc, trapped Indian Ocean lithosphere which later became the Molucca Sea plate. The collision caused clockwise rotation of the Philippine Sea plate, initiated the Sorong Fault system, and then eliminated the Molucca Sea by subduction on its east and west sides. The effects of collision propagated westwards through the region resulting in the initiation of new plate boundaries marked by regional unconformities. The arrival of the Sulawesi ophiolite, which collided with west Sulawesi in the late Oligocene, was the earliest event in collision between Sulawesi and the Bird’s Head microcontinent. Continental crust was thrust beneath Sulawesi in the early Miocene, and the Tukang Besi and Sula platforms were sliced in turn from the microcontinent, transferred to the west-moving Philippine Sea/Molucca Sea plate for a few million years, and finally accreted to Sulawesi. Reconstructing the Molucca Sea and Bird’s Head microcontinent suggests that most of the Banda Sea has a late Neogene extensional origin. Collision between the Philippine arc and the Eurasian continental margin in Taiwan at
c.
5 Ma is the key to present regional tectonics.
Characterizing petroleum charge systems in the tertiary of SE Asia
Authors: Todd S. P. , Dunn M. E. , Barwise A. J. G. 
Published: April 2008

Abstract

Most SE Asian Tertiary-aged petroleum has been derived from paralic (lower delta plain to prodelta, higher land plant dominated) source rocks, although the larger proportion of
oil
is from lacustrine (freshwater/brackish algal) sources. Because many SE Asian petroleum provinces have been largely explored without penetrating source rock, the source is inferred from the oil’s geochemistry. Prolific lacustrine sources develop mainly in
rift
lakes in the Palaeogene syn-rift megasequence common to many SE Asian basins, but
floodplain
lake sources are also important. Paralic source rocks include both coals and particularly coaly mudrocks developed within the Miocene post-rift megasequence with an oil-prone zone. Oil-prone source rocks are preferentially developed in the paralic realm between the lower coastal plain and lower estuary/delta front facies, perhaps involving a mangrove system. The stratigraphic position and kinetic expulsion behaviour of different source types, migration, seal timing and pressure-temperature-depth relationships converge to make younger plays, including carbonate buildups, more gas prone. The volumetric significance of biogenic gas is still poorly understood. Vertical migration is common in overpressured SE Asian basins; lateral migration is thus commonly restricted to distances of 20 km or less from the kitchen.
Exploring the lake basins of east and southeast Asia
Authors: Sladen Chris 
Published: April 2008

Abstract
SE Asia contains a large number of late Mesozoic and early Tertiary lake basins, that together contain a significant proportion of the world oil and gas reserves, oil shale reserves, and coal reserves. Exploration and production of oil and gas from these basins is likely to continue throughout the twenty-first century. As exploration for oil and gas continues, and fewer large fields remain to be found, it will become increasingly vital to focus expenditure on low risk, small volume opportunities in a manner that generates a return on investments. To achieve this, there needs to be a much more detailed understanding of lake basins and the sequences that fill them. This has to be combined with innovative technology to reduce well costs and increase flow rates per well, reductions in operating expenditures and greater flexibility in fiscal terms.
The tectonic evolution and associated sedimentation history of Sarawak Basin, eastern Malaysia: a guide for future hydrocarbon exploration
Authors: Mat-Zin I. C. , Swarbrick R. E. 
Published: April 2008

Abstract
A seismic-stratigraphic study of the reprocessed regional lines for the offshore Sarawak area was undertaken with the aim of reviewing the present understanding of the tectonics and the palaeo-depositional environments of the Sarawak Basin. The study was integrated with biostratigraphy and wireline-log data from the wells drilled throughout the basin.
Seven unconformities were identified within the Tertiary sediments and these were used as the markers for the seismic correlations. Where the unconformities become conformable, well data were used to guide the correlation of the conformities. Palaeo-environment maps were generated which document the interaction of tectonics and sediments throughout the basin history. The development of the Sarawak Basin commenced in late Oligocene times with deposition along a coastline running in a NW-SE direction, which is almost perpendicular to the present-day coastline. The coastline was oriented to the present-day NE-SW during late Miocene times.
Geochemistry of Sarawak Basin oils shows generation of hydrocarbons from land plant dominated source rocks. The distribution of these types of source rocks are favoured in the Coastal Fluvial, Coastal and Lower Coastal Plain environments. The quantity and quality of the source rocks deteriorates with the distance from the coastline. The palaeo-environment maps illustrate the likely distribution of Sarawak Basin source rocks which will help in effectively planning for future exploration in Sarawak.
The study also revealed that the Sarawak Basin was formed as a result of NW-SE-trending right-lateral fault movement during late Oligo-Miocene times. This dextral movement was responsible for creating the NW-SE coastline and divided the offshore Sarawak area into two sub-basins. Deposition and preservation of coastal plain and shallow marine sediments continued in the eastern area while the western area remained as a ‘high’ until late Miocene times. The dextral strike-slip movement which controlled the evolution of the Sarawak Basin is sub-parallel to a number of lineaments elsewhere in Sarawak. The timing of movement of these suggests progressive younging in an eastward direction. It is also believed the late structuration of the sediments and the formation of structural traps is linked to these tectonic movements.
A review of the petroleum potential of Papua New Guinea with a focus on the eastern Papuan Basin and the Pale Sandstone as a potential reservoir fairway
Authors: Boult P. J. 
Published: April 2008

Abstract
Substantial oil seeps were first reported from the eastern Papuan Basin in 1911, and oil has since been produced from the sub-surface, but not in commercial quantities. A significant discovery of gas in 1986 sparked an upsurge of activity within the adjacent western Papuan Basin. From 1986 to 1992, 13 new hydrocarbon discoveries were made, which included four major oil fields, and an oil pipeline for export purposes was then opened in 1992. This activity did not spread to the eastern Papuan Basin due to a perceived lack of good reservoir and the last well drilled there was over 30 years ago. In 1986, a potentially excellent reservoir, the Pale (Pah leh) Sandstone was discovered in outcrop in the eastern Papuan Basin. Thus the Papuan Basin as a whole remains an extremely prospective basin. However, due to high infrastructure costs most activity has recently been focussed on the already proven reservoir potential of the Late Jurassic Imburu and Toro Formations in the western section.
The extent of the Imburu-Toro Formation reservoir in the western section of the Papuan Basin is well documented. It was deposited as several regressive episodes within an overall transgressive, passive-margin, clastic sequence. In the eastern section, the Late Cretaceous Pale Sandstone was deposited in a barrier island or strand-plain environment. Lateral equivalents of the Pale Sandstone and the potential for a new reservoir fairway have been documented for a strike length of approximately 400 km. This fairway is coincident with the northeast edge of the western Papuan Basin and on the northern edge of the Aure and Port Moresby Troughs of the eastern Papuan Basin.
All the commercial oil accumulations and seeps found in the Papuan Basin before 1992 have been attributed to the Jurassic, with peak generation occurring in the Late Cretaceous prior to the formation of existing structures. In 1992 an oil seep was discovered which is geochemically very different to all the other oils found in the Papuan Basin. This was found to the north and east of the present discoveries that occur within the western Papuan Basin. The oil seep is indicative of undiscovered Tertiary source rock, which is currently at or near peak generation. However, most of this source rock in the north may be covered by overthrusted allochthonous terrain.
The Aure Trough was a Late Cretaceous to Tertiary rift basin that later developed into an Oligocene to Mid-Miocene foreland basin depocentre occurring on the northern and eastern margin of the Papuan Basin. It is proposed in this paper that mature Tertiary source rocks which occur within this foreland basin and the Pale Sandstone reservoir may form a significant petroleum system on the northeastern rim of the western Papuan Basin and within the eastern Papuan Basin.