Primary Migration Research Articles

Petroleum migration and trapping mechanism in fine-grained source rock formation

A petroleum system approach has been applied to exploration of hydrocarbon accumulations in the fine-grained source rocks (in situ) of the Upper Jurassic Bazhenov Formation. The study area comprises the Khantey anteclize in the central part of the West Siberian Basin. The Bazhenov petroleum system is a natural closed system, charge and trapping being in a rather deep marine siliceous formation, which contains mainly kerogen types II and I with extremely high oil-generating potential. The hydrocarbon kitchens and accumulation space in the source rock formation are unusually small and are located along fault planes. The timing of oil charge was Tertiary. The effect of the oil generation in the Bazhenov system was the generation of overpressure. Primary migration of oil was focused into macrofracture networks, located adjacent to the fault planes. Fault connectivity and macrofractured reservoir compartmentalization control the distribution of the Bazhenov oil-charged traps.

Volcanic reservoir rocks of northwestern Honshu island, Japan

Abstract The main Japanese oil producing region lies on the Japan Sea side of northern Honshu island. Although the total reserve is small and production supplies only threetenths of a percent of total Japanese oil consumption, it has two distinguishing features: (1) the main reservoir rocks are volcanic, pyroclastic, or tuffaceous, and (2) primary oil and gas migration seems to have taken place downward from the overlying source rocks. Marine volcanic activity since 15 Ma formed the main reservoir sections together with significant secondary porosity development. Thick and continuous deposition of organic-rich shales and mudstones followed and lower parts of these fine-grained rocks became the main source rocks. The principal direction of primary hydrocarbon migration occurred vertically downward from them. These fine-grained rocks seem to have acted as pressure seals as well as capillary seals over the oil/gas saturated zones below.

COAL AS A SOURCE OF OIL AND GAS: A CASE STUDY FROM THE BASS BASIN, AUSTRALIA

Only a few published geochemical studies have demonstrated that coals have sourced significant volumes of oil, while none have clearly implicated coals in the Australian context. As part of a broader collaborative project with Mineral Resources Tasmania on the petroleum prospectivity of the Bass Basin, this geochemical study has yielded strong evidence that Paleocene–Eocene coals have sourced the oil and gas in the Yolla, Pelican and Cormorant accumulations in the Bass Basin.Potential oil-prone source rocks in the Bass Basin have Hydrogen Indices (HIs) greater than 300 mg HC/g TOC. The coals within the Early–Middle Eocene succession commonly have HIs up to 500 mg HC/g TOC, and are associated with disseminated organic matter in claystones that are more gas-prone with HIs generally less than 300 mg HC/g TOC. Maturity of the coals is sufficient for oil and gas generation, with vitrinite reflectance (VR) up to 1.8 % at the base of Pelican–5. Igneous intrusions, mainly within Paleocene, Oligocene and Miocene sediments, produced locally elevated maturity levels with VR up to 5%.The key events in the process of petroleum generation and migration from the effective coaly source rocks in the Bass Basin are:the onset of oil generation at a VR of 0.65% (e.g. 2,450 m in Pelican–5);the onset of oil expulsion (primary migration) at a VR of 0.75% (e.g. 2,700–3,200 m in the Bass Basin; 2,850 m in Pelican–5);the main oil window between VR of 0.75 and 0.95% (e.g. 2,850–3,300 m in Pelican–5); and;the main gas window at VR >1.2% (e.g. >3,650 m in Pelican–5).Oils in the Bass Basin form a single oil population, although biodegradation of the Cormorant oil has resulted in its statistical placement in a separate oil family from that of the Pelican and Yolla crudes. Oil-to-source correlations show that the Paleocene–Early Eocene coals are effective source rocks in the Bass Basin, in contrast to previous work, which favoured disseminated organic matter in claystone as the sole potential source kerogen. This result represents the first demonstrated case of significant oil from coal in the Australian context. Natural gases at White Ibis–1 and Yolla–2 are associated with the liquid hydrocarbons in their respective fields, although the former gas is generated from a more mature source rock.The application of the methodologies used in this study to other Australian sedimentary basins where commercial oil is thought to be sourced from coaly kerogens (e.g. Bowen, Cooper and Gippsland basins) may further implicate coal as an effective source rock for oil.

Ongoing compression across South American plate: observations, numerical modelling and some implications for petroleum geology

Abstract The South American plate is now in horizontal compression and shortening. This is shown by stress data compilations, intraplate stress field numerical models and space-based geodetic results. Consistent with the compressive scenario, analyses of leak-off and hydraulic fracturing data indicate that the maximum principal stress is horizontal for most Brazilian basins. The observed compression/shortening is probably mostly due to the convergence of the South American and the Nazca plates and the divergence of the South American and the African plates. Plate-wide deformation related to the Andean tectonics has been evidenced by analyses of integrated visualizations of available plate-scale information on tectonics, continental geology, topography/bathymetry, seismicity, stresses, active deformation, residual isostatic anomalies, fission track analyses, and seismically derived Moho depths and P and S wave velocity anomalies. Here, some results of these analyses are presented and some implications of the ongoing compression for petroleum exploitation and exploration are discussed. A conceptual model for the plate-wide deformation is presented and numerically tested using elasto-plastic rheologies. The model states that in response to the compression, the lithosphere as a whole (or only the crust if thermal gradients are high enough) tends to fold and fracture. This tendency is stronger during peaks of the Andean orogeneses. The forming antiforms are responsible for uplift along the erosional basin borders, whereas the forming synforms are sites of continental sedimentation, at basin centres. The denudation of sedimentary covers promotes the exhumation of deeper and deeper rocks, cropping out at the foot of retreating scarps. Consequently, the erosional borders of the basins form local topography highs with respect to the adjacent basement. In exploration, neotectonics is usually simply disregarded, at least with regard to the exploratory activities developed in ‘passive’ margin basins. Nevertheless, we infer that neotectonics has an important role in the distribution and preservation of petroleum accumulations, since: (i) accumulations are ephemeral in a geological time scale, being strongly dependent on the seals’s fine geometry and biodegredation; (ii) a strong positive correlation exists between permeability anisotropy and maximum horizontal stress; (iii) the source rocks of the most important Subandean and intraplate petroleum systems are still in the oil generation window; and (iv) the disruption of ‘kitchens’ of generation is a positive factor to primary migration. This inference seems to be confirmed, since the most important South American petroleum accumulations are found along the actively deforming border between the South American and Caribbean plates. Indeed, the most important accumulations in marginal basins are found in the southeastern Brazilian margin (the Campos basin), which has been deformed the most with respect to other margins during the Cenozoic, and continues to be the most seismically active.

Percutaneous transluminal embolization with coils-treatment of pulmonary arteriovenous malformations.

The clinical values of coils embolization in the treatment of pulmonary arteriovenous malformations (PAVM) and related complications were investigated. Eleven patients with PAVMs verified by pulmonary arterial angiography were treated by transcatheter coils embolization. Chest X-ray (11 cases), computer tomography (7 cases) and/or magnetic resonance imaging (2 cases) were performed before embolization. Blood-gas analysis was done in 5 cases before and after embolization. The follow-up materials of 8 patients were collected to evaluate the effect of embolization with coils. The clinical manifestations included cerebral embolus, hemoptysis and decreased oxygenation in 9 patients and the remaining 2 had no symptoms. 9/11 cases were found by chest X-ray and 8 were diagnosed definitely. 7/7, 2/2 cases were diagnosed by CT or MR and diagnosis was made in all cases. Embolization was performed in 29 vessels. Partial pressure of oxygen in arterial blood of 5 cases changed significantly before and after embolization. Slight complications occurred in 6 patients, such as low fever, chest pain, pleurisy. The follow-up results showed that 7 cases were cured effectively. No primary and secondary device migration, and no medical paradoxical embolization occurred. It was concluded that coils embolization is a well-established method for treating PAVMs. It is a minimally invasive lung preserving treatment with high efficiency and less complication.

Biological targets of neurotoxic pesticides analysed by alteration of developmental events in the Mediterranean sea urchin, Paracentrotus lividus

Biological effects of neurotoxic insecticides widely used for agricultural purposes were studied using the early development of the Mediterranean sea urchin Paracentrotus lividus as a model. These compounds, dispersed as aerosols or powders in agricultural regions near to the coast, may affect the health of organisms in the marine environment. The biological effects of Basudin (an organophosphate compound containing 20% Diazinon), Diazinon (Dzn, a thionophosphate), Carbaryl and Pirimicarb (carbamates) on the early phases of sea urchin development were thus investigated. Morphological, biochemical, histochemical and immuno histochemical analyses were performed both during embryo and larval development. For the morphological effects on fertilisation and first cleavages, the effective concentration of insecticides was found to be 10 −4 M, while for further stages concentrations between 10 −5 and 10 −7 M were effective; 10 −3 M of any of these insecticides totally arrested development. During embryonic development, the treatment with organophosphates slowed the rate of early mitotic cycles down, affected nuclear and cytoskeletal status as well as DNA synthesis. From the gastrulation stage onwards, the main effects were exerted on the rate of primary mesenchyme cells migration, larval size, perioral arm length, and acetylcholinesterase activity distribution, thus deregulating the cholinergic system, which modulates cell-to-cell communication mediated by the signal molecule acetylcholine.

A look into the Val Verde Basin, Texas

Editor's note: This paper won the Best Poster Paper Award from the 2001 Annual Meeting in San Antonio. The study area consists of 180 miles2 within the Val Verde Basin. A new interpretation is proposed and is based primarily on 3D seismic data. Emphasis is placed on the Lower Permian to Pennsylvanian Section in which hydrocarbons have been found from tight reservoirs. The general stratigraphy is summarized, the focus being on hydrocarbon source, reservoirs, and seal. Seismic lines, spread across the area, illustrate structure. The producing fields sit atop the Foreland Thrust, which was transported as a decollement zone on Mississippian shales. A series of backthrusts is invoked to accommodate the movement of competent rocks up the ramped Foreland Thrust, creating the main structures in the fields. The Foreland Thrust is thought to be the primary migration pathway while the back-thrusts appear to be secondary migration pathways. The new interpretation incorporates 3D seismic, well, and reservoir performance data. The 3D seismic data, in particular, demonstrate the overall sequence stratigraphy of the basin and lead to a new structural interpretation. This interpretation is based mainly on 3D seismic data. Emphasis is placed on the Lower Permian to Pennsylvanian geologic section where hydrocarbons have been found in tight reservoirs. Currently, these reservoirs are being developed by Conoco Inc. in partnership with Tom Brown Inc. Geographically, the study area is located about 120 miles south of Midland in Texas. It encompasses Conoco's 3D seismic coverage in the Val Verde Basin and occupies an area roughly 30 × 6 miles. Geologically, the Val Verde Basin comprises the southern portion of the greater Permian Basin of mid-continent United States. It lies between the Central Basin Platform to the north and the Marathon Uplift to the south (Figure 1). Figure 1. Location map. Based on 2D seismic …

Mechanisms of void coarsening in helium implanted silicon

There has been recent discussion of the mechanisms that give rise to the observed coarsening of void populations introduced into silicon by implanting helium and then annealing to remove the helium. Over the temperature range from approximately 700 to 1000 °C and beyond, further annealing leads to an increase of the average void size and decrease in void density. This paper sets out to calculate the coarsening expected from the two primary potential mechanisms, migration and coalescence (M&C) and Ostwald ripening (OR). The methodology of the calculations is carefully set out together with the surface diffusion and vacancy diffusion parameters on which the mechanisms depend. For moderate anneal temperatures, up to 1000 °C, it would seem unlikely that OR can play any part in void coarsening. On the other hand, M&C calculations show that this mechanism gives results consistent with the size range found in experimental results.

Differential effects of angiostatin, endostatin and interferon-α1 gene transfer on in vivo growth of human breast cancer cells

The administration of different angiogenesis inhibitors by gene transfer has been shown to result in inhibition of tumor growth in animal tumor models, but the potency of these genes has been only partially evaluated in comparative studies to date. To identify the most effective anti-angiogenic molecule for delivery by retroviral vectors, we investigated the effects of angiostatin, endostatin and interferon(IFN)-alpha(1) gene transfer in in vivo models of breast cancer induced neovascularization and tumor growth. Moloney leukemia virus-based retroviral vectors for expression of murine angiostatin, endostatin and IFN-alpha(1) were generated, characterized, and used to transduce human breast cancer cell lines (MCF7 and MDA-MB435). Secretion of the recombinant proteins was confirmed by biological and Western blotting assays. Their production did not impair in vitro growth of these breast cancer cells nor their viability, and did not interfere with the expression of angiogenic factors. However, primary endothelial cell proliferation and migration in vitro were inhibited by supernatants of the transduced cells containing angiostatin, endostatin, and IFN-alpha(1). Stable gene transfer of the IFN-alpha(1) cDNA by retroviral vectors in both MCF7 and MDA-MB435 cells resulted in a marked and long-lasting inhibition of tumor growth in nude mice that was associated with reduced vascularization. Endostatin reduced the in vivo growth of MDA-MB435, but not MCF7 cells, despite similar levels of in vivo production, and angiostatin did not impair the in vivo growth of either cell line. These findings indicate heterogeneity in the therapeutic efficacy of angiostatic molecules delivered by viral vectors and suggest that gene therapy with IFN-alpha(1) and endostatin might be useful for treatment of breast cancer.

Negotiating survival: undocumented Mexican immigrant women in the Pacific Northwest

Current analyses of Mexico–U.S. migration theory generally are based on socioeconomic contexts and decision-making processes of male respondents. Further, limited data available on undocumented Mexican immigrant women mainly address the Mexico–U.S. border area, and adjacent U.S. urban centers. Our qualitative study focuses on undocumented Mexican immigrant women residing in central Washington State, where the regional economy is dominated by agribusiness development and dependent on immigrant and migrant farm labor. This paper assesses propositions of neoclassical economic and social capital theories of international migration in explaining the women’s migration decision-making processes. Project data indicate that while the Pacific Northwest has been a primary migration destination for sometime, it now may be increasingly a second-stage U.S. migration site, following initial migration to more traditional destinations such as California.

Cooling of the Sverdrup Basin during Tertiary basin inversion: implications for hydrocarbon exploration

ABSTRACT The regional thermal history of the north‐eastern Sverdrup Basin, Canadian Arctic Archipelago, has been assessed using apatite fission‐track thermochronology and vitrinite reflectance data. Fission‐track data for 27 samples from six wells through the Mesozoic section on Axel Heiberg and Ellesmere Islands reveal significant Palaeocene cooling associated with basin inversion during the Eurekan Orogeny. Fission‐track data for 29 outcrop samples, ranging in stratigraphic age from Cambrian to Tertiary, also reveal significant Palaeocene cooling. Vitrinite reflectance data from carbonaceous shales and coal seams in well and outcrop samples are consistent with these conclusions. The degree of Palaeocene cooling observed is greatest for well and outcrop samples in the cores of anticlines or the hanging walls of thrust faults, such as the Fosheim anticline, and faults, such as the Lake Hazen fault system, and the East Cape and Vesle Fiord thrust faults. Palaeocene cooling is largely attributed to the denudation of structures during the Eurekan Orogeny.At one locality on north‐western Ellesmere Island, which is on the northern flank of the Sverdrup Basin, the underlying Franklinian basement rocks yield Early Cretaceous fission track ages with relatively long mean track lengths. This indicates that this part of the basin was uplifted at this time and that subsequent sedimentation and subsidence in the Cretaceous and early Tertiary were modest. This locality thus appears to be on the rift shoulder, which developed along the flank of the Amerasia Basin in the Lower Cretaceous.At a locality on western Axel Heiberg Island, which is downflank from the rift shoulder, the Upper Jurassic Awingak sandstone has a Late Cretaceous fission track age. This is best explained by heating above the total annealing temperature for fission‐tracks in apatite by extensive Lower Cretaceous intrusions and subsequent heat dissipation and cooling in the Late Cretaceous followed by further substantial cooling due to Tertiary denudation.These results indicate that maximum burial temperatures occurred in the presently exposed Mesozoic section prior to basin inversion during the Eurekan Orogeny. It can therefore be inferred that peak hydrocarbon generation and primary migration predated the formation of structural traps during the Tertiary at shallow depths within the northern Sverdrup Basin.

Assessment of hydrocarbon source rock potential of Polish bituminous coals and carbonaceous shales

We analyzed 40 coal samples and 45 carbonaceous shale samples of varying thermal maturity (vitrinite reflectance 0.59% to 4.28%) from the Upper Carboniferous coal-bearing strata of the Upper Silesian, Lower Silesian, and Lublin basins, Poland, to evaluate their potential for generation and expulsion of gaseous and liquid hydrocarbons. We evaluated source rock potential based on Rock-Eval pyrolysis yield, elemental composition (atomic H/C and O/C), and solvent extraction yields of bitumen. An attempt was made to relate maceral composition to these source rock parameters and to composition of the organic matter and likely biological precursors. A few carbonaceous shale samples contain sufficient generation potential (pyrolysis assay and elemental composition) to be considered potential source rocks, although the extractable hydrocarbon and bitumen yields are lower than those reported in previous studies for effective Type III source rocks. Most samples analysed contain insufficient capacity for generation of hydrocarbons to reach thresholds required for expulsion (primary migration) to occur. In view of these findings, it is improbable that any of the coals or carbonaceous shales at the sites sampled in our study would be capable of expelling commercial amounts of oil. Inasmuch as a few samples contained sufficient generation capacity to be considered potential source rocks, it is possible that some locations or stratigraphic zones within the coals and shales could have favourable potential, but could not be clearly delimited with the number of samples analysed in our study. Because of their high heteroatomic content and high amount of asphaltenes, the bitumens contained in the coals are less capable of generating hydrocarbons even under optimal thermal conditions than their counterpart bitumens in the shales which have a lower heteroatomic content.

Fractionation of benzocarbazoles between source rocks and petroleums

The concentrations of the [a] and [c] isomers of benzocarbazoles in a number of crude oils and source rock bitumens were obtained by “in house methods” and from reported published data. The changes in benzocarbazole concentrations and the benzocarbazole [a]/([a]+[c]) ratio relating to source maturity, facies and migration are described. With increasing source maturity in North Sea oils and source rocks, up to 0.85% vitrinite reflectance equivalent, benzocarbazole concentrations increase due to generation followed by a decrease above 0.85% vitrinite reflectance equivalent due to expulsion/dilution by newly generated hydrocarbons. Comparison of benzocarbazole concentrations between reservoired petroleum and related source petroleum revealed a concentration bias in favour of source petroleum where concentrations of benzocarbazoles reached up to 10 times that found in equivalent reservoired petroleum. The differences in benzocarbazole concentrations between related oils and source rocks indicate that the major fractionation is introduced during primary migration and expulsion, because when secondary migration is limited, as in the Miller field, we see extensive benzocarbazole fractionation between reservoired petroleum and associated source petroleum. The relationships between source rock TOC content and petroleum benzocarbazole concentrations and [a]/([a]+[c]) ratios indicate that source organic matter exerts a strong influence on benzocarbazole distributions. The introduction of a reservoir source fractionation parameter (RSFP), defined as the ratio between the concentrations of benzo[a]-+benzo[c]carbazole in reservoired petroleum versus the concentration of benzo[a]-+benzo[c]carbazole in source petroleum, enables description of the relationship between reservoired petroleum and source petroleum from different petroleum systems. Petroleum deriving from clastic source rocks demonstrated high levels of benzocarbazole fractionation between reservoired petroleum and source petroleum during primary and secondary migration compared to petroleum deriving from carbonate systems. The RSFP parameter may also be used to examine fractionation effects during migration between different compound types. The more polar benzocarbazoles are fractionated more strongly than dibenzothiophene and phenanthrene between reservoired petroleum and source petroleum. Whereas sometimes source maturity signals do dominate the benzocarbazole signals in migrated oils, in other circumstances, often associated with clastic source rocks, no clear maturity signal is transferred to migrated oils.

Location of Adult Children as an Attraction for Black and White Elderly Primary Migrants in the United States

By using information on state of birth in the 1990 Census of the United States, the authors create a variable serving as a proxy for the distribution of adult children in 1985. This variable is then used in a two-level nested logit model to explain the 1985 – 90 interstate primary migration of elderly black people and elderly white people within the context of environmental amenities and other factors. The main findings are as follows. First, the location of adult children as well as environmental amenities are among the most important attractions for the primary migration of elderly black and white people. Their effects are stronger on white people than on black people. Because a relatively high proportion of out-migrated black adult children are located in the industrial states of the snowbelt and a relatively high proportion of their white counterparts are located in high-amenity states of the sunbelt, the attractions of adult children and environmental amenities are more prone to counter each other for elderly black people and to reinforce each other for elderly white people. Consequently, the net transfers of elderly primary migrants are small and somewhat oriented toward the snowbelt for black people, but they are voluminous and strongly oriented toward the sunbelt for white people. Second, the attraction of adult children is strong for not only the unmarried but also the married elderly, although it is somewhat stronger for the widowed aged 75 years and over. This finding can be taken as evidence for the viability of the ‘modified extended family’ system, which not only legitimizes the out-migration of adult children for career advancement but also encourages the migration of elderly parents to be close to their non-coresident children for services that require continual proximity. It also suggests that the elderly do not have a strong tendency to delay their migration toward non-coresident children until the loss of a spouse or becoming very old.

Massive recrystallization of low-Mg calcite at high temperatures in hydrocarbon source rocks: Implications for organic acids as factors in diagenesis

We document massive recrystallization of low-Mg calcite lime mudstone source rocks at moderately high temperatures in the Smackover Formation of Mississippi. This process was driven by organic acids produced during kerogen maturation and holds the implications for studies of primary migration of hydrocarbons, secondary porosity generation in reservoirs, and global environmental change. This interpretation is based on contrasting the following petrographic and bulk-rock geochemical characteristics of organic-poor vs. organic-rich lime mudstones:

石油システムにおける石炭からのガス生成機構の問題点

Recently source rock potentials on coals in Japan have attracted interests by the discoveries of Yufutsu oil/gas field and a new gas-field at offshore in Sanriku District, in which coals were assumed as their source rocks. The gas generation mechanism and gas potentials of coal as a source rocks in the petroleum system is discussed in this paper. On the van Krevelen diagram, several Japanese coals are plotted in the area between type II and type III organic matter. Petrographical and ultimate analyses on coals revealed that the high hydrogen contents of Japanese coals are caused by abundant degradinite, a maceral of vitrinite group. The degradinite is observed such mixture as very small fragments of the virinite (type III organic matter) and exnite (type II organic matter) under the microscope. The oil generation is assumed to begin at Ro=0.5, but only dehydration and decarboxylation continue until Ro =1.0, and the demethylation occurs later along the curve on van Krevelen diagram, resulting in the decrease of H/C atomic ratio. It is difficult for the degradinite in the oil window (Ro= 0.5 to 1.0) to generate hydrocarbons because of its difficulty of primary migration from coals. The compositions of gases from Japanese coal mines showed that CH4 content in hydrocarbon was more than 99% with a few exceptions. It suggests that little hydrocarbons are generated and migrated from coals in the oil window. Coals and terrestrial organic matters have been treated as gas source rocks only, and acknowledged to generated gas after Ro = 0.5 in the previous studies . However in the petroleum systems for the basins of non-marine or deltaic environment, hydrogen rich coals, such as Japanese coals, should be awarded that non-migrating oil-drops in micron size could have generated light hydrocarbons in the gas generation window when a thermal clacking of oil and bitumen begun.

Surfactants: Fundamentals and Applications in the Petroleum Industry

Book Review| December 01, 2001 Surfactants: Fundamentals and Applications in the Petroleum Industry JENNIFER D. SHOSA JENNIFER D. SHOSA 1Department of Geology Colby College Waterville, ME 04901 Search for other works by this author on: GSW Google Scholar PALAIOS (2001) 16 (6): 615. https://doi.org/10.1669/0883-1351(2001)016<0615:BRSFAA>2.0.CO;2 Article history first online: 03 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation JENNIFER D. SHOSA; Surfactants: Fundamentals and Applications in the Petroleum Industry. PALAIOS 2001;; 16 (6): 615. doi: https://doi.org/10.1669/0883-1351(2001)016<0615:BRSFAA>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyPALAIOS Search Advanced Search Laurier L. Schramm (Editor), 2000, Cambridge University Press, Cambridge, 621 p. (Hardcover $140.00) ISBN: 0-521-64067-9. For the past thirty years surfactants have played an increasingly important role in enhanced recovery of petroleum from reservoirs; but, it is not only secondary recovery efforts that benefit from an understanding of interfacial phenomena. Appreciation of the role interfacial forces play in multiphase fluid flow is also fundamental in the evaluation of primary and secondary migration of petroleum in sedimentary basins, and in the determination of the efficiency of seals. A better grasp of the physics of interfacial tension, therefore, enhances our ability to... You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Surfactants: Fundamentals and Applications in the Petroleum Industry

Laurier L. Schramm (Editor), 2000, Cambridge University Press, Cambridge, 621 p. (Hardcover $140.00) ISBN: 0-521-64067-9. For the past thirty years surfactants have played an increasingly important role in enhanced recovery of petroleum from reservoirs; but, it is not only secondary recovery efforts that benefit from an understanding of interfacial phenomena. Appreciation of the role interfacial forces play in multiphase fluid flow is also fundamental in the evaluation of primary and secondary migration of petroleum in sedimentary basins, and in the determination of the efficiency of seals. A better grasp of the physics of interfacial tension, therefore, enhances our ability to locate and exploit all economic oil reserves. Surfactants: Fundamentals and Applications to the Petroleum Industry explores and explains many of the effects of interfacial tension. For this reason, it is an indispensable addition to the petroleum geologist's library. This book is not exclusively for …

Spawning Migration of Lacustrine-Adfluvial Bull Trout in a Natural Area

We investigated the spawning migration of lacustrine-adfluvial bull trout Salvelinus confluentus in the North Fork Skokomish River in Olympic National Park (Washington State) during 1996. Day-snorkeling and electrofishing were conducted to determine timing and duration of the migration and the distribution and abundance of bull trout. The primary spawning migration began in early October and was waning by December. Bull trout migrated 6 km or less up the river from Lake Cushman. Increased river discharge and decreased water temperature appeared to be the primary environmental variables corresponding to the initiation of the migration. Mean length of migratory bull trout increased from June to December. Comparisons with other lacustrine-adfluvial bull trout populations in Oregon, Montana, Idaho, and British Columbia suggested that these populations exhibit specific migratory strategies related to local environmental conditions.

Natural gas composition in a geological environment and the implications for the processes of generation and preservation

Gases recovered from their location of formation (for example, gas recovered from drill cuttings) are enriched in C2+ components relative to gases recovered from reservoir production or testing streams. Because reservoir gases have been derived through a series of processes including generation from a source with a specific chemical character, primary and secondary migration, accumulation and (selective) preservation, the compound distribution within these reservoir gases is less likely to be representative of the generation process than in situ gases such as cuttings gas. Thus, rather than comparing compound distributions within reservoir or pipeline gas data, to test whether laboratory catalysis experiments for the generation of gas are consistent with geological systems, it is better to compare laboratory results of the distribution of gas compounds with gas data for which the opportunity for a wide range of different processes can be precluded. The mismatch between compound distributions within cuttings gas recovered from fine grained rocks and those recovered from laboratory experiments disproves the hypothesis of gas generation catalysis in geological systems, whereas the distribution of compounds within cuttings gas is consistent with simple, non-catalytic cracking. The generation of natural gas in geological systems has been inferred, in some publications, to be a universally catalytic process on the basis of observations made during laboratory experiments. However, this extrapolation has been predicated on the premise that the distribution of compounds within natural gas (% methane in C1–C4) in reservoirs is different from that observed from non-catalytic or simple cracking experiments, and that reservoir gas precisely represents natural gas composition as it is generated within source rocks. The extrapolation of the inferred kinetic stability of low molecular weight hydrocarbons such as propane determined during high temperature (⩾530°C), low pressure (<600 mm Hg), water-free experiments to geological time scales yields lower reaction rates than those actually observed for geological systems: the inferred catalytically mediated kinetics yield reaction rates that are too high. These observations, coupled with the proof that transition metal catalysis is not operating in geological environments, suggest that the overall kinetic controls under geological conditions are different from those in the dry, quartz, laboratory experiments.