Inferring reservoir data from dynamic production data has long been done through matching the production history. However, proper integration of available production history has always been a challenge. Different production history data such as well pressure and water cut often occur at different scales making their joint inversion difficult. Furthermore, production data obtained from the same well or even the same reservoir are often correlated making a significant portion of the dataset redundant. Thirdly, the massiveness of the data recorded from wells in a large reservoir over a long period of time makes the nonlinear inversion of such data computational demanding. In this paper, we propose the integration of multiwell production data using wavelet transform. The method involves the use of a two-dimensional wavelet transformation of the data space in order to integrate multiple production data and reduce the correlation between multiwell data. Multiple datasets from different wells, representing different production responses (pressure, water cut, etc.), were treated as a single matrix of data rather than separate vectors that assume no correlation amongst datasets. This enabled us to transform the multiwell production data into a two-dimensional wavelet domain and subsequently select the most important wavelets for history match. By minimizing the square of the Frobenius norm of the residual matrix we were able to match the calculated response to the observed response. We derived the relationship that allows us to replace a conventional minimization of the sum of squares of the l2 norms of multi-objective functions with the minimization of the square of the Frobenius norm of the integrated data. The usefulness of the approach is demonstrated using two examples. The approach proved very effective at reducing correlation between multiwell data. In addition, the method helped to reduce the cost of computing sensitivity coefficients. However, the method gave poor prediction of water cut when the datasets were not scaled before inverse modeling. 相似文献
Human activities are exposing freshwater ecosystems to a wide range of stressors, whose direct and indirect effects can be alleviated or exacerbated through interactive effects with dynamic environmental drivers. This study used long-term data from two Neotropical lacustrine freshwater systems (Batata Lake, an Amazonian floodplain lake and Imboassica lagoon, an Atlantic coastal lagoon) subjected to different kinds of environmental fluctuations (i.e., flood pulse and sandbar opening) and anthropogenic impacts (i.e., siltation and eutrophication). Our objective was to determine whether the effects of human perturbations are contingent on modifications of important biotic and abiotic characteristics through environmental variability. For both ecosystems, environmental variability consistently interacted with anthropogenic perturbations to alter most of the variables analyzed, such as nutrient dynamics, chlorophyll-a concentration, zooplankton and benthic invertebrate species richness, and temporal community stability, which indicates that interactive effects between environmental variability and anthropogenic perturbations may impact a myriad of ecosystem properties. Furthermore, the nature of these interactive effects was highly dependent on the variable considered and on the ecosystem analyzed. For example, at Imboassica lagoon, sandbar openings interacted synergistically with trophic state to increase the phosphorus concentration in the water column. At Batata Lake, flooding generally alleviated the negative effects of siltation on species richness by both diluting inorganic suspended material concentration and by promoting local recruitment from the regional species pool. Such results indicate that our ability to understand and predict the outcome of anthropogenic impacts on inland aquatic systems can be hampered if we consider human stressors as “static” phenomena disconnected from dynamic interactions with major local environmental drivers. 相似文献
The distribution and nutritional profiles of sub-tidal seagrasses from the Torres Strait were surveyed and mapped across an area of 31,000 km2. Benthic sediment composition, water depth, seagrass species type and nutrients were sampled at 168 points selected in a stratified representative pattern. Eleven species of seagrass were present at 56 (33.3%) of the sample points. Halophila spinulosa, Halophila ovalis, Cymodocea serrulata and Syringodium isoetifolium were the most common species and these were nutrient profiled. Sub-tidal seagrass distribution (and associated seagrass nutrient concentrations) was generally confined to northern-central and south-western regions of the survey area (<longitude 142.60), where mean water depth was relatively shallow (approximately 13 m below MSL) and where sediments were comprised primarily muddy sand to gravelly sand. Seagrass nitrogen and starch content, the most important nutrients for marine herbivores, were significantly correlated with species and with the plant component (above or below ground). For all seagrass species, the above-ground component (shoots and leaves) possessed greater nitrogen concentrations than the below-ground component (roots and rhizomes), which possessed greater starch concentrations. S. isoetifolium had the highest total nitrogen concentrations (1.40±0.05% DW). However, it also had higher fibre concentrations (38.2±0.68% DW) relative to the other four species. H. ovalis possessed the highest starch concentrations (2.76±0.12% DW) and highest digestibility (83.24±0.66% DW) as well as the lowest fibre (27.2±0.66% DW). The high relative abundance (found at 55% of the sites that had seagrass) and nutrient quality characteristics of H. ovalis make it an important source of energy to marine herbivores that forage sub-tidally in the Torres Strait. There were two regions in Torres Strait (north-central and south-western) where sub-tidal seagrass meadows were prevalent and of relatively higher nutritional value. This spatial and nutritional information can be used by local agencies to manage and to protect the ecological, economic and cultural values of the sub-tidal seagrass ecosystems and associated fisheries of the Torres Strait. 相似文献
U/Pb SHRIMP ages of nine Variscan leucocratic orthogneisses from the central Tauern Window (Austria) reveal three distinct pulses of magmatism in Early Carboniferous (Visean), Late Carboniferous (Stephanian) and Early Permian, each involving granitoid intrusions and a contemporaneous opening of volcano-sedimentary basins. A similar relationship has been reported for the Carboniferous parts of the basement of the Alps further to the west, e.g. the “External massifs” in Switzerland. After the intrusion of subduction-related, volcanic-arc granitoids (374?±?10?Ma; Zwölferkogel gneiss), collisional intrusive-granitic, anatectic and extrusive-rhyolitic/dacitic rocks were produced over a short interval at ca. 340?Ma (Augengneiss of Felbertauern: 340?±?4?Ma, Hochweißenfeld gneiss: 342?± 5?Ma, Falkenbachlappen gneiss: 343?±?6?Ma). This Early Carboniferous magmatism, which produced relatively small volumes of melt, can be attributed to the amalgamation of the Gondwana-derived “Tauern Window” terrane with Laurussia–Avalonia. Probably due to the oblique nature of the collision, transtensional phenomena (i.e. volcano-sedimentary troughs and high-level intrusives) and transpressional regimes (i.e. regional metamorphism and stacked nappes with anatexis next to thrust planes) evolved contemporaneously. The magmas are mainly of the high-K I-type and may have been generated during a short phase of decompressional melting of lithospheric mantle and lower crustal sources. In the Late Carboniferous, a second pulse of magmatism occurred, producing batholiths of calc-alkaline I-type granitoids (e.g. Venediger tonalite: 296?±?4?Ma) and minor coeval bodies of felsic and intermediate volcanics (Heuschartenkopf gneiss: 299?±?4?Ma, Peitingalm gneiss: 300?±?5?Ma). Prior to this magmatism, several kilometres of upper crust must have been eroded, because volcano-sedimentary sequences hosting the Heu- schartenkopf and Peitingalm gneisses rest unconformably on 340-Ma-old granitoids. The youngest (Permian) period of magma generation contains the intrusion of the S-type Granatspitz Central Gneiss at 271?±?4?Ma and the extrusion of the rhyolitic Schönbachwald gneiss protolith at 279?±?9?Ma. These magmatic rocks may have been associated with local extension along continental wrench zones through the Variscan orogenic crust or with a Permian rifting event. The Permian and the above-mentioned Late Carboniferous volcano-sedimentary sequences were probably deposited in intra-continental graben structures, which survived post-Variscan uplift and Alpine compressional tectonics. 相似文献
Hgbomite, a rare exotic mineral, is found to be associated with the vanadiferous–titaniferous(V-Ti) bearing magnetite bands at Bhakatarhalli, Nuggihalli greenstone belt, western Dharwar Craton, India. We report on a second occurrence of hgbomite from the Dharwar craton in Karnataka, which is the sixth documented occurrence of this mineral from India. We evaluate the chemical characteristics of hgbomite and associated Fe-Ti-minerals in an attempt to identify its formation as a primary hydrothermal mineral in a metamorphosed magnetite layer.We report here the presence of hgbomite as a complex oxide of Fe, Mg, Al and Ti with accessory of Zn, V and Sn. Petrographic studies suggest the(V–Ti) bearing magnetite(Mt) contain spinel, hgbomite, chlorite, martite, ilmenite(Il) and minor amounts of diaspore. The hgbomite displays euhedral to subhedral textures, and is up to 250 μm along the grain boundaries of magnetite and ilmenite. In the samples studied, hgbomite is prismatic, irregular and elongated in shape. The genesis of hgbomite in veins between magnetite and ilmenite implies its precipitation from fluids without involving complicated reactions. Several models were proposed for the formation of hgbomite; however, the subject is still debatable. 相似文献
Evaluating yearly net migration for the Federal Republic of Germany establishes the importance of demographic restructuring and government policies as explanations for the counterurbanization phenomenon. Counterurbanization, the spatial demographic deconcentration of regional population, is measured as an inverse relationship between the net migration rate and population sizes of functional urban regions. A counterurbanization pattern filtered-down from older to younger age-groups of the population, and appears related to an increasing preference for small-sized regions with natural amenities. For foreigners, a counterurbanization direction of movement can be explained by changes in immigration laws. While counterurbanization may be slowing down during the 1980s in certain developed countries, such as the United States, in the Federal Republic the phenomenon intensifies throughout the 1970–84 time period. Based on broad national demographic changes in combination with agespecific patterns of movement, this strong counterurbanization trend should continue well into the future. 相似文献
The incorporation of hydrogen in enstatite in a hydrous system containing various amounts of NaCl was investigated at 25 kbar.
The hydrogen content in enstatite shows a clear negative correlation to the NaCl-concentration in the system. The most favourable
explanation is the reduction of water fugacity due to dilution. Other reasons for the limited hydrogen incorporation at high
NaCl levels, such as a significant influence of Na+ on the defect chemistry or an exchange between OH- and Cl−in enstatite, appear much less important. A partition coefficient DNaEn/Fluid = 0.0013 could be determined, demonstrating that Na is less incompatible in enstatite than H. The new results support the
idea that dissolved components have to be considered when the total hydrogen storage capacity in nominally anhydrous minerals
is estimated, especially in geological settings with high levels of halogens, such as subduction zones. 相似文献
The Jervois region of the Arunta Inlier, central Australia, contains para- and orthogneisses that underwent low-pressure
amphibolite facies metamorphism (P = 200–300 MPa, T = 520–600 °C). Marble layers cut by metre-wide quartz + garnet ± epidote veins comprise calcite, quartz, epidote, clinopyroxene,
grandite garnet, and locally wollastonite. The marbles also contain locally discordant decimetre-thick garnet and epidote
skarn layers. The mineral assemblages imply that the rocks were infiltrated by water-rich fluids (XCO2 = 0.1–0.3) at ∼600 °C. The fluids were probably derived from the quartz-garnet vein systems that represent conduits for fluids
exsolved from crystallizing pegmatites emplaced close to the metamorphic peak. At one locality, the marble has calcite (Cc)
δ18O values of 9–18‰ and garnet (Gnt) δ18O values of 10–14‰. The δ18O(Gnt) values are only poorly correlated with δ18O(Cc), and the δ18O values of some garnet cores are higher than the rims. The isotopic disequilibrium indicates that garnet grew before the
δ18O values of the rock were reset. The marbles contain ≤15% garnet and, for water-rich fluids, garnet-forming reactions are
predicted to propagate faster than O-isotopes are reset. The Sm-Nd and Pb-Pb ages of garnets imply that fluid flow occurred
at 1750–1720 Ma. There are no significant age differences between garnet cores and rims, suggesting that fluid flow was relatively
rapid. Texturally late epidote has δ18O values of 1.5–6.2‰ implying δ18O(H2O) values of 2–7‰. Waters with such low-δ18O values are probably at least partly meteoric in origin, and the epidote may be recording the late influx of meteoric water
into a cooling hydrothermal system.
Received: 29 April 1996 / Accepted: 12 March 1997 相似文献
Detailed analysis of basal organic deposits underlying Hammock River marsh, Connecticut allowed documentation of water-level changes that occurred between 13,000 and 6000 yrs B.P. Four main periods of groundwater- and lake-level movements and related environmental changes can be identified.
1. (1) 12,500-10,200 yrs B.P. (lake stage): very rapid rise of the groundwater table of about 2 to 3 m, resulting in a shallow lake, followed by a more gradual rise of about 2.5 to 1.5 m.
2. (2) 10,200-7000 yrs B.P. (freshwater marsh, stage 1): slow overall rise of the water table interrupted by a drop of at least 1 m between about 9500 and 9000 yrs B.P. and of at least 0.8 m between about 8000 and 7500 yrs B.P., each event leading to oxidation and maceration of organic material.
3. (3) 7000-6400 yrs B.P. (complete desiccation of the swamp): rapid fall of the water table of at least 3.9 m. causing large-scale down-wasting of the accumulated peat.
4. (4) After 6400 yrs B.P. (freshwater marsh, stage 2): rapid rise of the water table.
The water-table rise of period 1 and the lowering of period 3 are attributed to predominantly local causes, while the groundwater fluctuations during period 2 are probably climate-related. The final water-level increase reflects the influence of Holocene relative sea-level rise. 相似文献