Petroleum Possibilities Research Articles

Assessment of the possibility of natural and associated petroleum gases storage in the hydrate state

The purpose of this work is to study the natural gas hydrates formation and decomposition processes. Natural gases from the Otradninsky and Srednevilyuisky gas condensate fields were chosen as models of associated petroleum gases. In this paper, the natural gas hydrates formation in water, in a 2% sodium bicarbonate solution was studied and the kinetic parameters of the hydrates decomposition were determined. It has been established that the hydrate formation of natural gas with a higher relative density begins at lower pressures at the same temperature. The degree of water conversion into hydrate increases with a decrease of the gas relative density. Compared to water, the stability of hydrates obtained in sodium bicarbonate solution is almost 2 times higher. The concentration of C2-C4 methane homologues in hydrates leads to an increase of the gas fat coefficient. The conclusion is made about the possibility of the natural and associated petroleum gases utilization and storage in the hydrate state. Keywords: natural gas; associated petroleum gas; utilization; natural gas hydrates; equilibrium conditions of hydrate formation; bicarbonate-sodium type water; fat coefficient.

The presence of radioactive materials in soil, sand and sediment samples of Potenga sea beach area, Chittagong, Bangladesh: Geological characteristics and environmental implication

Abstract Accurate quantification of naturally occurring radioactive materials in soil provides information on geological characteristics, possibility of petroleum and mineral exploration, radiation hazards to the dwelling populace etc. Of practical significance, the earth surface media (soil, sand and sediment) collected from the densely populated coastal area of Chittagong city, Bangladesh were analysed using a high purity germanium γ-ray spectrometer with low background radiation environment. The mean activities of 226Ra (238U), 232Th and 40K in the studied materials show higher values than the respective world average of 33, 36 and 474 Bq/kg reported by the UNSCEAR (2000). The deduced mass concentrations of the primordial radionuclides 238U, 232Th and 40K in the investigated samples are corresponding to the granite rocks, crustal minerals and typical rocks respectively. The estimated mean value of 232Th/238U for soil (3.98) and sediment (3.94) are in-line with the continental crustal average concentration of 3.82 for typical rock range reported by the National Council on Radiation Protection and Measurements (NCRP). But the tonalites and more silicic rocks elevate the mean value of 232Th/238U for sand samples amounting to 4.69. This indicates a significant fractionation during weathering or associated with the metasomatic activity in the investigated area of sand collection.

Soil-borne polycyclic aromatic hydrocarbons in El Paso, Texas: Analysis of a potential problem in the United States/Mexico border region

Ultrasonic extraction followed by Stir Bar Sorptive Extraction (SBSE) and thermal desorption inline coupled with Gas Chromatography and Mass Spectrometry (TD/GC/MS) was used to perform a comprehensive determination of soil-borne polycyclic aromatic hydrocarbons (PAHs) in El Paso, Texas. The method provided good sensitivity and faster processing time for the analysis. The total PAHs in El Paso soil ranged from 0.1 to 2225.5 μg kg −1. Although the majority of PAH concentrations did not exceed the soil screening levels regulated by the United States Environmental Protection Agency, the existence of PAHs in this ecosystem is ubiquitous. Naphthalene were found in 100% of the soil samples; while the heavy PAHs (five- and six-ring) were not often detected and mostly remained in closer proximity to industrial areas and major traffic points. The results ruled out the possibility of petroleum refining as the significant source of local soil-borne PAH contamination, but they suggested that the PAHs found in El Paso soil were closely linked to human activities and possible other industrial processes.

Petroleum possibilities of the Cuervo trough, Tucumcari Basin, New Mexico

Petroleum possibilities of the Cuervo trough, Tucumcari Basin, New Mexico

PETROLEUM IN GLACIALLY‐RELATED SANDSTONES OF GONDWANA: A REVIEW

The supercontinent of Gondwana (Antarctica, Africa, Australia, South America, India, the Arabian Peninsula, Madagascar and Sri Lanka) covered more than six times the combined area of the United States and Brazil. In this paper, the petroleum occurrences and potential of glacially‐related rocks of Carboniferous‐Permian age in this vast area are reviewed in terms of basin types, reservoirs, seals, traps and source rocks.Significant amounts of heavy oil, sourced by Precambrian algal‐rich shales, are produced from glacially‐related sandstones in some 20 fields in Oman. Bolivia has 27 oil‐ and gasfields sourced from underlying Devonian shales, and oil production occurs in two fields in nearby Argentina. In Australia, there is production from two basins: the Cooper Basin has 24 productive fields (mostly gas), and the Canning Basin has six small fields. In Brazil, four non‐commercial shows have been found in the Paraná Basin and one in the Amazonas Basin. In Paraguay, southern Africa and India, there is no production from glacially‐related sandstones.Production and shows occur in cratonic basins either in the interior or along the margins of Gondwana, except for those in Bolivia, Argentina and South Africa, which occur in foreland basins.Sandstone reservoirs were deposited mostly as glacial outwash, as small deltas, either in lakes or marine basins, or as turbidites in marine basins bordered by continental ice sheets. Seals are diamictites, mudstones, shales and possibly diabases in the Paraná Basin. Traps include tectonic and salt‐related anticlines as well as pinch‐outs against glacial channels. Glacial outwash and glacio‐marine sandstones are thus important petroleum exploration targets.Commercial production to date is sourced from both older and younger non‐glacial beds. The fields in Oman were sourced by Precambrian algal‐rich shales, and those in Bolivia and adjacent Argentina by Devonian and possibly Silurian organic‐rich shales. The source of the gas in the Cooper Basin is from overlying coal beds. Neither modern marine, high‐latitude muds nor ancient glacially‐influenced marine shales contain sufficient organic material to be considered adequate source rocks.This review indicates that petroleum production in Gondwana's glaciogenic deposits mostly occurs in cratonic and passive margin basins; it occurs wholly in sandstone reservoirs, chiefly in structural traps, and nearly everywhere, reservoirs are sourced by hydrocarbons from non‐glaciogenic shales (either older or younger). The only “glacially unique” features of petroleum in Gondwana deposits are its seals of diamictites, which surely must also be true when considering the petroleum possibilities of older ancient glacial and glacially‐influenced deposits.

Evaluation of Petroleum Possibilities of Subsurface Lower Miocene Deposits in the Gulf of Suez-Egypt: ABSTRACT

Evaluation of Petroleum Possibilities of Subsurface Lower Miocene Deposits in the Gulf of Suez-Egypt: ABSTRACT

Petroleum Possibilities in Continental Margin off Central Chile: ABSTRACT

Petroleum Possibilities in Continental Margin off Central Chile: ABSTRACT

A SEISMIC MODEL OF FAULTS IN THE COOPER BASIN

A synthetic seismic section was modelled to help in the interpretation of Cooper Basin seismic lines which cross major faults and exhibit shadow zones.A major fault bounding the northwest flank of the Packsaddle Structure in the Merrimelia-Innamincka Farmout Block in South Australia was selected for modelling. A geological cross-section postulated on the basis of wells on either side of the fault was fed into the seismic modelling package AIMS (Advanced Interpretive Modelling System — licensed by Geoquest International Inc.) to produce a synthetic seismic line. This synthetic line provided a realistic match with an actual seismic line across the fault. Pre-stack migration of the actual seismic data is suggested to provide additional evidence for the reliability of the model.The shadow zone in the synthetic section is caused by dipping events in the fault shadow zone created by compaction of the Toolachee and Patchawarra Formations along the hanging wall of the fault plane. The dipping events cause reflected energy to be detected outside the fault zone. The large component of compaction within the Permian section is largely ascribed to thick coal horizons. The possibility of petroleum traps in the hanging wall of the fault is inferred and drilling is recommended.

Paleogene petroleum possibilities in the Philippines

Recent deep offshore drillings and detailed onshore geological studies have increased the importance of the Paleogene section of the Philippines as a possible hydrocarbon producer. Geochemistry of source rocks, shows, and production tests from this horizon indicates the generation of oil and gas. Isotopic analysis shows no correlation between the oil now being produced in reservoirs of Lower Miocene age, and the contemporaneous shale, a potential source rock, thus suggesting deeper, older sections as the possible source. In the past, exploration has been focused on Neogene reservoirs and source rocks and has resulted in very modest success. It is anticipated that the present inclination of explorationists to test the Paleogene section will lead to more definitive data and economic discoveries.

Hydrocarbon gas in sediment from the shelf, slope, and basin of the Bering Sea

Hydrocarbon gases (methane, ethane, ethene, propane, propene, isobutane and n-butane) are present in low concentrations in the top two meters of sediment from the shelf, slope and basin of the Bering Sea. Methane is most abundant and its concentration increases with depth in the sediment. Average concentrations of methane recovered from these sediments are between about 4000 and 5000 nl per 1 of interstitial water. Ethane, ethene, propane and propene are present in almost all samples, but the concentrations of these gases are about two orders of magnitude lower than the concentration of methane. The average ratios of ethane to ethene are usually greater than one in shelf sediment, about one in slope sediment, and usually less than one in basin sediments. These hydrocarbon gases are probably derived from low-temperature chemical and biochemical processes operating at or near the sea-floor. At one location on the shelf, hydrocarbon gases suggest the possibility of petroleum at depth.

Petroleum Possibilities in Altar Desert, Sonora, Mexico: ABSTRACT

A late Miocene-early Pliocene marine basin has been identified in the northwestern corner of the State of Sonora, Mexico. The existence of the Altar basin has been established by geophysical means. Its stratigraphy and hydrocarbon generation potential are known from the geologic history of the adjoining areas. The geology of the Altar basin is compared to basins of the same age in California which have been proven to contain more than 27 billion bbl of oil. The San Andreas fault system is a very important factor in the oil possibilities of the region. End_of_Article - Last_Page 716------------

Geology and Petroleum Possibilities of Grand Banks, Newfoundland: ABSTRACT

Geology and Petroleum Possibilities of Grand Banks, Newfoundland: ABSTRACT

Concealed Mesozoic-Cenozoic Alpine Himalayan Geosyncline and Its Petroleum Possibilities

An alpine Mesozoic-Cenozoic geosyncline and its various zones are present in the Himalayas. Delineation is based on the synthesis of classic geologic data from the Himalayas and adjacent regions of Afghanistan, Tibet, Burma, Thailand, and Malaysia. A geotectonic model is proposed which significantly differs from earlier models and is compatible with geophysical data. The possible existence of an alpine shelf-miogeosyncline concealed below the nappes of older rocks mobilized from the hinterland zone is of scientific and economic interest in view of its petroleum potential.

Stratigraphy and Petroleum Possibilities of Middle Tertiary Rocks in Puerto Rico: REPLY

Strata of Oligocene and Miocene ages are present on both the Atlantic and Caribbean coasts of Puerto Rico. The strata range in composition from sand and gravel to pure limestone. In northern Puerto Rico seven formations are recognized including four units of coralline and algal limestone. In southern Puerto Rico only two formations are recognized and both are redefined in this paper. The lower formation consists largely of clastic materials, but it locally contains one thick body of reef limestone. The upper formation is here restricted to a thick, very fossiliferous reef limestone. The strata of middle Tertiary age contain a few folds and minor faults in northern Puerto Rico, but in southern Puerto Rico the strata are cut by many faults, some of which have displacements of several hundred meters. The reef limestones in both northern and southern Puerto Rico could serve as adequate source and reservoir rocks for petroleum and natural gas. Further study is recommended for several anticlines in northern Puerto Rico and along the faults between Ponce and Guayanilla in southern Puerto Rico that might serve as traps for oil and gas.

Stratigraphy and Petroleum Possibilities of Middle Tertiary Rocks in Puerto Rico: DISCUSSION

Stratigraphy and Petroleum Possibilities of Middle Tertiary Rocks in Puerto Rico: DISCUSSION

Stratigraphy and Petroleum Possibilities of Middle Tertiary Rocks in Puerto Rico: DISCUSSION

Interpretation, stratigraphic nomenclature, age of rocks (biostratigraphy, foraminifera); separate discussions by Moussa and Seiglie, and by Meyerhoff; for reference to paper by Monroe, W. H., see Am. Assoc. Pet. Geol., Bull., Vol. 57, No. 6, 1973

Geology and Petroleum Possibilities in and Around Gulf of St. Lawrence

The Gulf of St. Lawrence is the largest embayment on the Atlantic Coast of North America between Florida and the Labrador Sea. Surface geology, geophysical data, and subsurface well control define four structural units and extend them from the land areas across the gulf. Beds having possibilities for oil and gas production are present in early Paleozoic formations overlying Precambrian basement in the Anticosti basin and western Newfoundland fault belt; in middle Paleozoic beds overlying Taconic basement in the Gaspe fold belt; and in late Paleozoic formations overlying Acadian basement in the Maritimes basin. The southward continuation of this Acadian basement is exposed on various uplands in Nova Scotia, and also underlies the Sydney, Fundy, and other basins, and extend beneath the great Mesozoic and Tertiary sedimentary wedge of the Scotian basin of the continental shelf. Production has not been obtained from wells drilled in the Anticosti basin--a relatively stable monocline. Many gas and oil shows have been found throughout Ordovician rocks; Silurian rocks may be productive in deeper parts of the basin. The Gaspe fold belt is thrust over the south edge of the Anticosti basin and is overlapped by the north edge of the Maritimes basin. Many seeps and shows of oil, but only insignificant recovery, have come from structurally complex Devonian beds in the likely part of the fold belt. In places, the Silurian beds may be productive, too. The allochthonous or klippe sequence of the western Newfoundland fault belt has been complexly thrust over the autochthonous sequence at the eastern margin of the Anticosti basin. Porosity and shows have been found in Ordovician formations in both structural sequences; very minor oil production has been obtained from shallow wells. The Maritimes basin, a large complex intermontane basin of Middle Devonian to Permian sedimentary rocks, has one small oil and gas field producing from Mississippian sandstones. The presence, at the southeast, of a thick sedimentary section, sizeable structures, porous sandstones and carbonate rocks, many shows and seeps, oil shales, and albertite encourage exploration, especially in the Mississippian Horton and Windsor Groups and the Pennsylvanian coarse-fluvial facies. Although estimated values for oil and gas in place in these four structural units may be quite large, the Paleozoic age of the sedimentary section, the low-grade metamorphism in some parts of the area, the generally poor porosity at depth, and the large area under water where operations are very expensive all reduce the commercial potential.

Geology and Petroleum Possibilities in and Around Gulf of St. Lawrence: ABSTRACT

The Gulf of St. Lawrence is the largest embayment on the Atlantic Coast of North America between Florida and the Labrador Sea. In this region, surface geology provides the main control for defining four structural units which can be extended into or across the Gulf using published geophysical data and available well control. Prospective beds are found in early, middle, and late Paleozoic formations which in turn overlie Precambrian, Taconic, and Acadian basement. Acadian basement rocks underlying the Maritimes basin, Sydney basin, Fundy basin, etc., are exposed in parts of Nova Scotia, and continue south beneath the great Mesozoic and Tertiary sedimentary wedge of the Scotian basin. Production has not been obtained in the Anticosti basin, but most Ordovician formations have yielded gas and oil shows. The thick, gently dipping, early Paleozoic section is fairly prospective. Many seeps and shows, but insignificant oil recoveries, come from Devonian formations in the Gaspe fold belt; the Silurian also may be prospective in this structurally complex area. The Cambro-Ordovician section in both the klippe and autochthonous sequences in the western Newfoundland fault belt is prospective; seeps, shows, and very minor oil production have come from Ordovician porous zones. In the Maritimes basin, the presence of one small oil and gas field, many shows and seeps, oil shale and albertite, pronounced structures, and a thick sedimentary section have maintained interest and act vity in this large intermontane basin of Late Devonian to Permian sedimentary rocks. Carboniferous End_Page 2149------------------------------ sandstones and carbonate rocks provide the best prospects. Although estimated values for oil and gas in place in these four structural units may be quite large, the Paleozoic age of the sedimentary section, the low grade metamorphism in some parts of the area, the generally poor porosity at depth, and the large area under water where operations are very expensive all reduce considerably the commercial potential. End_of_Article - Last_Page 2150------------

Stratigraphy and Petroleum Possibilities of Middle Tertiary Rocks in Puerto Rico

Strata of Oligocene and Miocene ages are present on both the Atlantic and Caribbean coasts of Puerto Rico. The strata range in composition from sand and gravel to pure limestone. In northern Puerto Rico seven formations are recognized including four units of coralline and algal limestone. In southern Puerto Rico only two formations are recognized and both are redefined in this paper. The lower formation consists largely of clastic materials, but it locally contains one thick body of reef limestone. The upper formation is here restricted to a thick, very fossiliferous reef limestone. The strata of middle Tertiary age contain a few folds and minor faults in northern Puerto Rico, but in southern Puerto Rico the strata are cut by many faults, some of which have displacements of several hundred meters. The reef limestones in both northern and southern Puerto Rico could serve as adequate source and reservoir rocks for petroleum and natural gas. Further study is recommended for several anticlines in northern Puerto Rico and along the faults between Ponce and Guayanilla in southern Puerto Rico that might serve as traps for oil and gas.

Geology and Petroleum Potentials of Central and South Afghanistan

Afghanistan is in a broad mobile belt extending mainly east-west between the old shield of Fennosarmatia in the north and Gondwana in the south. Four major geotectonic units separated by deep-seated fault systems can be recognized. These units are: (1) North Afghan-Tadjik unit, (2) East Iran-Central Afghan unit, (3) East Afghanistan-West Pakistan unit, and (4) marginal region of the Indian shield. In central and south Afghanistan the following blocks can be distinguished: in the East Iran-Central Afghan unit, the Farah, Helmand, and Seistan fault blocks; in the East Afghanistan-West Pakistan unit, the Nooristan fault block, and in the marginal region of the Indian shield, the Katawaz fault block. No prospects, or at best poor prospects, exist for the discovery of economically exploitable petroleum in the Farah, Helmand, Seistan, and Nooristan fault blocks. Petroleum possibilities are assumed to exist in the Katawaz fault block of southeastern Afghanistan. The Katawaz fault block is the only one in southern Afghanistan in which a maximum of 9,000 m (30,000 ft) of late Paleozoic, Mesozoic, and Paleogene sediments have been deposited on the basement. The facies are predominantly marine. Potential reservoir rocks probably are represented by clastic strata deposited at the Cretaceous-Tertiary transition and by sandstone intercalated in the Paleogene sequence. Good to excellent trapping conditions could exist in regularly folded anticlines of Oligocene age as much as 50 km (30 mi) long. Depositional wedges within the subsurface Mesozoic and Paleogene formations could be present. Seismic reconnaissance surveys would provide more precise data pertinent to the existence of favorable structures.