This paper explores the relationship between the original and its translation by interpreting Benjamin's three metaphors from his The Translator's Task. The exploration starts with the metaphor of"the tan...This paper explores the relationship between the original and its translation by interpreting Benjamin's three metaphors from his The Translator's Task. The exploration starts with the metaphor of"the tangent of a circle",where it is interpreted that although the translated version should be faithful to its original in terms of meaning,yet it is a deviation due to different internal and external factors. Then,in the metaphor of"afterlife",the discussion demonstrates that the translated version proceeds from the original,but the original depends on it for its survival and afterlife in different eras. Later,based on the metaphor of"fragments of a vessel",the author states that the original and its translation are equal and complementary,just like the fragments of a vessel,responsible for the development and renewal of each other through translation. Finally,it is concluded that a better understanding of their relationship can offer us a new perspective in translation studies and practice.展开更多
[Objective] The aim was to explore the relationship between water body Chlorophyll-a and water quality factors of wetlands Baiguishan reservoir.[Method] Chlorophyll-a and water quality factors of water quality of Wetl...[Objective] The aim was to explore the relationship between water body Chlorophyll-a and water quality factors of wetlands Baiguishan reservoir.[Method] Chlorophyll-a and water quality factors of water quality of Wetlands BaiGuishan Reservoir was studied,the analysis of the relationship on water quality of Wetlands Baiguishan Reservoir was made by use of trophic status indices and SPSS17.0 statistical analysis.[Result] Total phosphorus was an important factor of influence Chlorophyll-a in reservoir,water body had slight eutrophication phenomenon in reservoir of July to October in 2010.[Conclusion] Comprehensive management should be strengthened so as to improve the water quality of Baiguishan wetland.展开更多
Dolostones in the Cambrian Longwangmiao Formation have become one of the most significant gas exploration domains in China. Over a trillion cubic meters of gas reservoirs have been discovered in the Gaoshiti-Moxi area...Dolostones in the Cambrian Longwangmiao Formation have become one of the most significant gas exploration domains in China. Over a trillion cubic meters of gas reservoirs have been discovered in the Gaoshiti-Moxi area; however, the origins and distribution of the dolostone reservoirs are not well understood. This work discussed the geology and geochemistry of the dolostone reservoirs in the Longwangmiao Formation to determine their origin and distribution. Two understandings are acquired: firstly, a carbonate ramp provided excellent conditions for grain beach deposition, while the presence of a hypersaline lake was favorable for the contemporaneous dolomitization of grain beach deposits. Petrographic and geochemical evidence further confirm that the Longwangmiao dolostone was formed during the contemporaneous stage. Secondly, the reservoir characteristics indicate that the grain beach sediments provide material basis for the development of the Longwangmiao dolostone reservoirs. Reservoir dissolution simulation experiments show that the porosity of the reservoirs was formed by dissolution during contemporaneous and burial stages. The dissolution pores formed during the contemporaneous stage were controlled by sequence interfaces. The large scale dissolution vugs formed during the burial stage subsequently spread along the pre-existing porosity and fracture zones. This study therefore identified that the development of grain dolostone reservoirs in a shallow water ramp under arid climatic conditions generally met the following conditions:(1) reefal beach deposits lay a foundation for reservoir development;(2) superficial conditions are an important determining factor for reservoir porosity; and(3) burial conditions provide environment for porosity preservation and modification.展开更多
Carboniferous carbonate reservoirs at the eastern edge of the Pre-Caspian Basin have undergone complex sedimentation,diagenesis and tectonism processes,and developed various reservoir space types of pores,cavities and...Carboniferous carbonate reservoirs at the eastern edge of the Pre-Caspian Basin have undergone complex sedimentation,diagenesis and tectonism processes,and developed various reservoir space types of pores,cavities and fractures with complicated combination patterns which create intricate pore-throats structure.The complex pore-throat structure leads to the complex porosity-permeability relationship,bringing great challenges for classification and evaluation of reservoirs and efficient development.Based on the comprehensive analysis on cores,thin sections,SEM,mercury intrusion,routine core analysis and various tests,this paper systematically investigated the features and main controlling factors of pore-throats structure and its impact on the porosity-permeability relationship of the four reservoir types which were pore-cavity-fracture,pore-cavity,pore-fracture and pore,and three progresses are made.(1)A set of classification and descriptive approach for pore-throat structure of Carboniferous carbonate reservoirs applied to the eastern edge of the Pre-Caspian Basin was established.Four types of pore-throat structures were developed which were wide multimodal mode,wide bimodal mode,centralized unimodal mode and asymmetry bimodal mode,respectively.The discriminant index of pore-throat structure was proposed,realizing the quantitative characterization of pore-throat structure types.(2)The microscopic heterogeneity of pore reservoir was the strongest and four types of pore-throat structures were all developed.The pore-fracture and pore-cavity-fracture reservoirs took the second place,and the microscopic heterogeneity of pore-cavity reservoir was the weakest.It was revealed that the main controlling factor of pore-throat structure was the combination patterns of reservoir space types formed by sedimentation,diagenesis and tectonism.(3)It was revealed that the development of various pore-throat structure types was the important factor affecting poroperm relationship of reservoirs.The calculation accuracy of permeability of reservoirs can be improved remarkably by subdividing the pore-throat structure types.This study deepens the understanding of pore-throat structure of complicated carbonate reservoirs,and is conducive to classification and evaluation,establishment of precise porosity-permeability relationship and highly efficient development of carbonate reservoirs.展开更多
This study is based on the Tong sheep obtained by the random sampling method of typical colonies in the central area of Baishui County in Shaanxi Province, China. An investigation was undertaken to clarify the gene co...This study is based on the Tong sheep obtained by the random sampling method of typical colonies in the central area of Baishui County in Shaanxi Province, China. An investigation was undertaken to clarify the gene constitution of blood protein and nonprotein types of Tong sheep. Twelve genetic markers were examined by starch-gel electrophoresis and cellulose acetate electrophoresis. Polymorphism in Tong sheep was found at the following 10 loci, transferrin (Tf), alkaline phosphatase (Alp), leucine aminopeptidase (Lap), arylesterase (Ary-Es), hemoglobin-β (Hb-β), X-protein (X-p), carbonic anhydrase (CA), catalase (Cat), malate dehydrogenase (MDH), and lysine (Ly), whereas, albumin (A1) and postalbumin (Po) loci were monomorphic. Genetic approach degree method and phylogenetic relationship clustering method were used to judge the origin and phylogenetic status of Tong sheep. Results from both methods maintained that Tong sheep belonged to the "Mongolia group", and Mongolia sheep was the origin of Tong sheep. This was also supported by the history of Tong sheep breeding. Compared to the phylogenetic relationship clustering method, the genetic approach degree method was more reliable for the extraction from East and South of Central Asia, and was more effective in reflecting the breeding course of Tong sheep.展开更多
At present, the Tibetan Mastiff is the oldest and most ferocious dog in the world. However, the origin of the Tibetan Mastiff and its phylogenetic relationship with other large breed dogs such as Saint Bernard are unc...At present, the Tibetan Mastiff is the oldest and most ferocious dog in the world. However, the origin of the Tibetan Mastiff and its phylogenetic relationship with other large breed dogs such as Saint Bernard are unclear. In this study, the primers were designed accord- ing to the mitochondrial genome sequence of the domestic dog, and the 2,525 bp mitochondrial sequence, containing the whole sequence of Cytochrome b, tRNA-Thr, tRNA-Pro, and control region of the Tibetan Mastiff, was obtained. Using grey wolves and coyotes as out- groups, the Tibetan Mastiff and 12 breeds of domestic dogs were analyzed in phylogenesis. Tibetan Mastiff, domestic dog breeds, and grey wolves were clustered into a group and coyotes were clustered in a group separately. This indicated that the Tibetan Mastiff and the other domestic dogs originated from the grey wolf, and the Tibetan Mastiff belonged to Carnivora, Canidae, Canis, Canis lupus, Canis lupus familiaris on the animal taxonomy. In domestic dogs, the middle and small breed dogs were clustered at first; German Sheepdog, Swedish Elkhound, and Black Russian Terrier were clustered into one group, and the Tibetan Mastiff, Old English Sheepdog, Leonberger, and Saint Bernard were clustered in another group. This confirmed the viewpoint that many of the famous large breed dogs worldwide such as Saint Bernard possibly had the blood lineage of the Tibetan Mastiff, based on the molecular data. According to the substitution rate, we concluded that the approximate divergence time between Tibetan Mastiff and grey wolf was 58,000 years before the present (YBP), and the approximate divergence time between other domestic dogs and grey wolf was 42,000 YBP, demonstrating that the time of origin of the Tibetan Mastiff was earlier than that of the other domestic dogs.展开更多
Comparing compositions of the fluid inclusions in volcanic rocks to the contents and isotopes of the gases in corresponding volcanic reservoirs using microthermometry, Raman microspectroscopy and mass spectrum analysi...Comparing compositions of the fluid inclusions in volcanic rocks to the contents and isotopes of the gases in corresponding volcanic reservoirs using microthermometry, Raman microspectroscopy and mass spectrum analysis, we found that: (1) up to 82 mole% methane exists in the primary inclusions hosted in the reservoir volcanic rocks; (2) high CH4 inclusions recognized in the volcanic rocks correspond to CH4-bcaring CO2 reservoirs that are rich in helium and with a high ^3He/^4He ratio and which show reversed order of 813C in alkane; (3) in gas reservoirs of such abiotic methane (〉80%) and a mix of CH4 and CO2, the enclosed content of CH4 in the volcanic inclusions is usually below 42 mole%, and the reversed order of δ^13C in alkane is sometimes irregular in the corresponding gas pools; (4) a glassy inclusion with a homogeneous temperature over 900℃ also contains a small portion of CH4 although predominantly CO2. This affinity between gas pool and content of inclusion in the same volcanic reservoirs demonstrates that magma-originated gases, both CH4 and CO2, have contributed significantly to the corresponding gas pools and that the assumed hydrocarbon budget of the bulk earth might be much larger than conventionally supposed.展开更多
Abundant organic inclusions are present in the Qinglong antimony deposit. However, the source rocks of these organic matters have not been reliably identified. Recently, a paleo--oil reservoir was found in the Qinglon...Abundant organic inclusions are present in the Qinglong antimony deposit. However, the source rocks of these organic matters have not been reliably identified. Recently, a paleo--oil reservoir was found in the Qinglong antimony deposit. In view of similar components of gaseous hydrocarbon, we propose that the organic matters observed in inclusions in Qinglong antimony deposit would come from this paleo-oil reservoir. We used the Re-Os dating method to determine the age of the bitumen from this paleo-oil reservoir, and obtained an isochron age of 254.3~2.8 Ma. The age indicates that the oil- generation from source rock occurred in the early Late Permian, earlier than the Sb mineralization age (-148~8.5 Ma) in the Qinglong antimony deposit area. After oil generation from Devonian source rock, first and secondary migration, the crude oil have probably entered into the fractures and pores of volcanic rocks and limestone and formed a paleo-oil reservoir in the western wing of Dachang anticline. As burial process deepened, the crude oil has turned into natural gas, migrates into the core of Dachang anticline and formed a paleo-gas reservoir. The hydrocarbons (including CH4) in the reservoirs can serve as reducing agent to provide the sulfur required for Sb mineralization through thermal chemical reduction of sulfates. Therefore, the formation of oil-gas in the area is a prerequisite for the Sb mineralization in the Qinglong antimony deposit.展开更多
The genus Sheathia consists of over 20 species primarily distributed in Asia,Europe,Oceania,North America,and Africa.However,the origin and evolution of this genus remain unclear.Two gametophyte stage specimens(SAS180...The genus Sheathia consists of over 20 species primarily distributed in Asia,Europe,Oceania,North America,and Africa.However,the origin and evolution of this genus remain unclear.Two gametophyte stage specimens(SAS18052 and SAS18523)and two“Chantransia”stage specimens(YTS19161 and YTS19017)were collected from Shanxi and Henan Provinces in China,respectively.Based on morphological data,isolates YTS19161 and YTS19017 were similar to Audouinella pygmaea,whereas the morphological characteristics of SAS18052 and SAS18523 were in good agreement with the circumscription description of S.longipedicellata.Molecular sequences of rbc L,COI-5P,and psb A were used to investigate the phylogenetic,evolutionary,and biogeographic origin of the genus Sheathia.The three molecular markers supported that the two gametophyte stage specimens belong to S.longipedicellata,while the isolates YTS19161 and YTS19017 were the“Chantransia”of S.longipedicellata.Ancestral area reconstruction and divergence time estimation speculated that Sheathia originated in North America,a portion of the Pangaea at approximately 328.07-184.73 million years ago(Ma).Our relaxed molecular clock analysis suggests that the Florideophyceae diverged approximately 741.04(894.36-631.70)Ma.The major divergences in this class involved the emergence of Nemaliophycidae[ca.662.01(779.83-580.51)Ma],and the split of orders Batrachospermales and Thoreales[ca.456.10(552.80-367.88)Ma].展开更多
This paper utilizes multi-methods,such as core observation,slice identification,isotope analysis,trace element analysis,fluid inclusion technique and so on,to study the causes of the dolomite in the Nanpu Sag and the ...This paper utilizes multi-methods,such as core observation,slice identification,isotope analysis,trace element analysis,fluid inclusion technique and so on,to study the causes of the dolomite in the Nanpu Sag and the origins of the dolomite reservoir.The study results show that the forming environment of dolomite in the Nanpu Sag is a fresh-water lake environment,and the dolomite is the product of dolomitization which is caused by volcanic thermal fluids in the Early Dongying period.With the development of intergranular pores in the dolomitization process,a lot of dissolved pores/vugs and fractures were formed by denudation in the later periods because of the influence of thermal fluids including the associated fluids of volcanic activities and the expelled hydrocarbon fluids of the source rocks.On the whole,these secondary dissolution spaces greatly enhance the reservoir ability of the dolomite,and there are enough reservoir spaces in the dolomite in the Nanpu Sag.展开更多
Based on the five-year long dynamic tracking and investigation of the peasant households of the Lishu village, the influences by small town construction on the economy and employment of the original peasant households...Based on the five-year long dynamic tracking and investigation of the peasant households of the Lishu village, the influences by small town construction on the economy and employment of the original peasant households are discussed. On the one hand, small town construction plays a positive role in adjustment of the industrial structure of the original peasant households and in the transfer of their employment towards non-agricultural industries. On the other hand the economic growth of the original peasant households is not so well sustainable, and is so fluctuating. Moreover, the unbalance of income distribution of the said households has been furthered, and small town construction has made the existing labor surplus of the original peasant households more serious, particularly the women labor surplus.展开更多
The Middle Ordovician subsalt Majiagou Formation in the Ordos Basin comprises pervasively dolomitized shallow marine limestone and is a major reservoir rich in natural gas resources.Four types of dolomite matrix and c...The Middle Ordovician subsalt Majiagou Formation in the Ordos Basin comprises pervasively dolomitized shallow marine limestone and is a major reservoir rich in natural gas resources.Four types of dolomite matrix and cement were identified based on petrographic textures:(very)finely crystalline,non-planar to planar-s matrix dolomite(Md1);finely to medium crystalline,planar-s to planar-e matrix dolomite(Md2);microbialites comprising dolomite microcrystals(Md3);and finely to coarsely crystalline dolomite cement(Cd).The Md1 and Md2 dolomites were controlled by alternating lagoon-shoal facies and haveδ13C values(−1.89 to+1.45‰VPDB for Md1,−1.35 to+0.42‰VPDB for Md2)that fall within or are slightly higher than the coeval seawater,suggesting the dolomitizing fluid of evaporated seawater.Md2 dolomite was then subjected to penecontemporaneous karstification by meteoric water and burial recrystallization by sealed brines during diagenesis,as indicated by its relatively lowerδ18O values(−8.89 to−5.73‰VPDB)and higher 87Sr/86Sr ratios(0.708920–0.710199).Md3 dolomite comprises thrombolite and stromatolite and is interpreted to form by a combination of initial microbial mediation and later replacive dolomitization related to evaporated seawater.Cd dolomite was associated with early-formed karst system in the Md2 host dolomite.The lowestδ18O values(−11.78 to−10.18‰VPDB)and 87Sr/86Sr ratios(0.708688–0.708725)and fluid inclusion data(Th:123–175°C)indicate involvement of hydrothermal fluid from which the Cd dolomite precipitated during deep burial.These results reveal the multi-stage dolomitization history of the Majiagou Formation and provide new constraints on fluid origins and dolomites evolution during deep burial in old superimposed basins,such as the Ordos Basin and elsewhere.展开更多
Recently, significant oil discoveries have been made in the shallower pay zones of the Jurassic Badaowan Formation (J_(1)b) in the Mahu Sag, Junggar Basin, Northwest China. However, little work has been done on the ge...Recently, significant oil discoveries have been made in the shallower pay zones of the Jurassic Badaowan Formation (J_(1)b) in the Mahu Sag, Junggar Basin, Northwest China. However, little work has been done on the geochemical characteristics and origins of the oil in the J_(1)b reservoir. This study analyzes 44 oil and 14 source rock samples from the area in order to reveal their organic geochemical characteristics and the origins of the oils. The J_(1)b oils are characterized by a low Pr/Ph ratio and high β-carotene and gammacerane indices, which indicate that they were mainly generated from source rocks deposited in a hypersaline environment. The oils are also extremely enhanced in C_(29) regular steranes, possibly derived from halophilic algae. Oil-source correlation shows that the oils were derived from the Lower Permian Fengcheng Formation (P_(1)f) source rocks, which were deposited in a strongly stratified and highly saline water column with a predominance of algal/bacterial input in the organic matter. The source rocks of the Middle Permian lower-Wuerhe Formation (P_(2)w), which were deposited in fresh to slightly saline water conditions with a greater input of terrigenous organic matter, make only a minor contribution to the J_(1)b oils. The reconstruction of the oil accumulation process shows that the J_(1)b oil reservoir may have been twice charged during Late Jurassic–Early Cretaceous and the Paleogene–Neogene, respectively. A large amount volume of hydrocarbons generated in the P_(1)f source rock and leaked from T_(1)b oil reservoirs migrated along faults connecting source beds and shallow-buried secondary faults into Jurassic traps, resulting in large-scale accumulations in J_(1)b. These results are crucial for understanding the petroleum system of the Mahu Sag and will provide valuable guidance for petroleum exploration in the shallower formations in the slope area of the sag.展开更多
In the long-term symbiotic evolution process,the town areas along the Yangtze River and its natural and cultural landscapes have presented a sound "city-scene" landscape form. But with the implementation of ...In the long-term symbiotic evolution process,the town areas along the Yangtze River and its natural and cultural landscapes have presented a sound "city-scene" landscape form. But with the implementation of the Three Gorges project,the town relocation as well as the flooding in the natural and human landscape area,the original harmonious "city-scene" pattern started to collapse and fell into the situation of "fragmentation" and "islanding". The differentiation between city and landscape,uncoordinated scale and fractured urban context become pressing issues that affect the integral form optimization of the town areas. This paper aims at responding to the call of the government about proceeding the construction of the Yangtze River economic belt under the ecological and green strategy and seeking an attuned "cityscene" relationship of the town area. Based on the analysis of the dynamic evolution of the "city-scene" relationship,the paper also pointed out that the urban construction around the reservoir area in the postThree Gorges era was the key stage of "scene-city" integration and symbiosis while the maintenance of scenery pattern,the harmony of space scale and the protection of living culture should be applied as the vital strategies.展开更多
The olive is widely cropped in Tunisia where also oleaster trees thrive all around orchards and in natural sites. Little is known on the genetic relationships between the olive crop and oleaster trees in Tunisia. Fift...The olive is widely cropped in Tunisia where also oleaster trees thrive all around orchards and in natural sites. Little is known on the genetic relationships between the olive crop and oleaster trees in Tunisia. Fifty-two oleaster trees and fifteen cultivars were sampled from Tunisia. SSR genotyping was performed in polyacrylamide gels after fluorescent labeling. We used seven nuclear and two chloroplast SSR markers. AFC analyses showed close genetic relationships between cultivated and oleaster trees. Genetic relationships were also displayed in a dendrogram based on Unweighted Pair Group Method (UPGMA). Five clusters were defined mixing cultivar and oleaster trees suggesting close relationship between some cultivar and some oleaster trees. One oleaster is single in a cluster. The chlorotype SSR markers show probably three olive origins. Some cultivars have the CE chlorotype originates from the East of the Mediterranean basin, the CCK haplotype originates from Maghreb and the COM chlorotype originates from West Mediterranean. The cultivars were 1) introduced from the East;2) selected in the West;3) or selected in the North Africa region. The Tunisian oleaster trees carry eastern and western Mediterranean chlorotype CCK, COM and CE.展开更多
Origin of authigenic dolomites in the dolomitic reservoir of the Permian Fengcheng Formation in the Mahu Sag of Junggar Basin is unclear.Occurrence and genetic evolution of the authigenic dolomites in dolomitic rock r...Origin of authigenic dolomites in the dolomitic reservoir of the Permian Fengcheng Formation in the Mahu Sag of Junggar Basin is unclear.Occurrence and genetic evolution of the authigenic dolomites in dolomitic rock reservoir of the Fengcheng Formation in the Mahu Sag were analyzed by polarized and fluorescence thin sections,scanning electron microscope(SEM),electron microprobe(EMP),C,O and Sr isotopes analysis,and other techniques.(1)Dolomites were mainly precipitated in three stages:penecontemporaneous-shallow burial stage(early stage of the Middle Permian),middle burial stage(middle stage of the Middle Permian),and middle-deep burial stage,with the former two stages in dominance.(2)Dolomitization fluid was high-salinity brine originating from alkaline lake.In the penecontemporaneous-shallow burial stage,Mg^(2+)was mainly supplied by alkaline-lake fluid and devitrification of volcanic glass.In the middle burial stage,Mg^(2+)mainly came from the transformation of clay minerals,devitrification of volcanic glass and dissolution of aluminosilicates such as feldspar.(3)Regular changes of Mg,Mn,Fe,Sr,Si and other elements during the growth of dolomite were mainly related to the alkaline-lake fluid,and to different influences of devitrification and diagenetic alteration of volcanic materials during the burial.(4)In the penecontemporaneous stage,induced by alkaline-lake microorganisms,the micritic-microcrystalline dolomites were formed by primary precipitation,replacement of aragonite and high-Mg calcite,and other processes;in the shallow burial stage,the silt-sized dolomites were formed by continuous growth of micritic-microcrystalline dolomite and replacement of calcites,tuffs and other substances;in the middle burial stage,the dolomites,mainly silt-and fine-sized,were formed by replacement of volcanic materials.The research results are referential for investigating the formation mechanism and distribution patterns of tight dolomitic reservoirs in the Mahu Sag and other similar oil and gas bearing areas.展开更多
Methane-rich fluids were recognized to be hosted in the reservoir volcanic rocks as primary inclusions. Samples were collected from core-drillings of volcanic gas reservoirs with reversed δ13C of alkane in the Xujiaw...Methane-rich fluids were recognized to be hosted in the reservoir volcanic rocks as primary inclusions. Samples were collected from core-drillings of volcanic gas reservoirs with reversed δ13C of alkane in the Xujiaweizi depression of the Songliao Basin. The volcanic rocks are rhyolite dominant being enriched in the more incompatible elements like Cs, Rb, Ba, Th, U and Th with relative high LREE, depleted HREE and negative anomalies of Ti and Nb, suggesting a melt involving both in mantle source and crustal assimilation. Primary fluids hosted in the volcanic rocks should have the same provenance with the magma. The authors concluded that the enclosed CH4 in the volcanics are mantle/magma-derived alkane and the reversed δ13C of alkane in the corresponding gas reservoirs is partly resulted from mixture between biogenic and abiogenic gases.展开更多
Secondary storage spaces with very complex geometries are well developed in Ordovician carbonate reservoirs in the Tarim Basin,which is taken as a study case in this paper.It is still not clear how the secondary stora...Secondary storage spaces with very complex geometries are well developed in Ordovician carbonate reservoirs in the Tarim Basin,which is taken as a study case in this paper.It is still not clear how the secondary storage space shape influences the P-& S-wave velocities (or elastic properties) in complex carbonate reservoirs.In this paper,three classical rock physics models (Wyllie timeaverage equation,Gassmann equation and the Kuster-Toks z model) are comparably analyzed for their construction principles and actual velocity prediction results,aiming at determining the most favourable rock physics model to consider the influence of secondary storage space shape.Then relationships between the P-& S-wave velocities in carbonate reservoirs and geometric shapes of secondary storage spaces are discussed from different aspects based on actual well data by employing the favourable rock physics model.To explain the influence of secondary storage space shape on V P-V S relationship,it is analyzed for the differences of S-wave velocities between derived from common empirical relationships (including Castagna's mud rock line and Greenberg-Castagna V P-V S relationship) and predicted by the rock physics model.We advocate that V P-V S relationship for complex carbonate reservoirs should be built for different storage space types.For the carbonate reservoirs in the Tarim Basin,the V P-V S relationships for fractured,fractured-cavernous,and fractured-hole-vuggy reservoirs are respectively built on the basis of velocity prediction and secondary storage space type determination.Through the discussion above,it is expected that the velocity prediction and the V P-V S relationships for complex carbonate reservoirs should fully consider the influence of secondary storage space shape,thus providing more reasonable constraints for prestack inversion,further building a foundation for realizing carbonate reservoir prediction and fluid prediction.展开更多
Natural gases of shallow reservoirs with the carbon isotopic compositions of methane ranging from -50‰ to -60‰ (PDB) were considered as mixed gases of biogenic and thermogenic origins previously and some of them wer...Natural gases of shallow reservoirs with the carbon isotopic compositions of methane ranging from -50‰ to -60‰ (PDB) were considered as mixed gases of biogenic and thermogenic origins previously and some of them were considered as low-mature (or low temperature thermogenic) gases lately. In this paper natural gases with the carbon isotopic compositions of methane in the above range were identified using the molecular and stable carbon isotopic compositions of methane, ethane and propane. The mixed gases of biogenic and mature thermogenic origins display the characteristics of {δ{}+{13}C-1} ranging from -50‰ to -60‰, {δ{}+{13}C-2}>-35‰, Δ values ({δ{}+{13}C-3}-{δ{}+{13}C-2})< 5‰ and C-1/∑C++-2 ratios < 40. Immature to low|mature gases display the characteristics of {δ{}+{13}C-1} ranging from -50‰ to -60‰, {δ{}+{13}C-2} < -40‰, Δ values ({δ{}+{13}C-3}-{δ{}+{13}C-2}) >7‰, and C-1/∑C++-2 ratios >60.展开更多
文摘This paper explores the relationship between the original and its translation by interpreting Benjamin's three metaphors from his The Translator's Task. The exploration starts with the metaphor of"the tangent of a circle",where it is interpreted that although the translated version should be faithful to its original in terms of meaning,yet it is a deviation due to different internal and external factors. Then,in the metaphor of"afterlife",the discussion demonstrates that the translated version proceeds from the original,but the original depends on it for its survival and afterlife in different eras. Later,based on the metaphor of"fragments of a vessel",the author states that the original and its translation are equal and complementary,just like the fragments of a vessel,responsible for the development and renewal of each other through translation. Finally,it is concluded that a better understanding of their relationship can offer us a new perspective in translation studies and practice.
基金Supported by Natural Science Study Fund from the Department of Education of Henan(2010B610002)
文摘[Objective] The aim was to explore the relationship between water body Chlorophyll-a and water quality factors of wetlands Baiguishan reservoir.[Method] Chlorophyll-a and water quality factors of water quality of Wetlands BaiGuishan Reservoir was studied,the analysis of the relationship on water quality of Wetlands Baiguishan Reservoir was made by use of trophic status indices and SPSS17.0 statistical analysis.[Result] Total phosphorus was an important factor of influence Chlorophyll-a in reservoir,water body had slight eutrophication phenomenon in reservoir of July to October in 2010.[Conclusion] Comprehensive management should be strengthened so as to improve the water quality of Baiguishan wetland.
基金granted by the National Major Science and Technology Projects (grant No.2016ZX05004002)PetroChina Major Science and Technology Projects (grant No.2014E-32)PetroChina Science and Technology Projects (grant No.2016B-0402-01)
文摘Dolostones in the Cambrian Longwangmiao Formation have become one of the most significant gas exploration domains in China. Over a trillion cubic meters of gas reservoirs have been discovered in the Gaoshiti-Moxi area; however, the origins and distribution of the dolostone reservoirs are not well understood. This work discussed the geology and geochemistry of the dolostone reservoirs in the Longwangmiao Formation to determine their origin and distribution. Two understandings are acquired: firstly, a carbonate ramp provided excellent conditions for grain beach deposition, while the presence of a hypersaline lake was favorable for the contemporaneous dolomitization of grain beach deposits. Petrographic and geochemical evidence further confirm that the Longwangmiao dolostone was formed during the contemporaneous stage. Secondly, the reservoir characteristics indicate that the grain beach sediments provide material basis for the development of the Longwangmiao dolostone reservoirs. Reservoir dissolution simulation experiments show that the porosity of the reservoirs was formed by dissolution during contemporaneous and burial stages. The dissolution pores formed during the contemporaneous stage were controlled by sequence interfaces. The large scale dissolution vugs formed during the burial stage subsequently spread along the pre-existing porosity and fracture zones. This study therefore identified that the development of grain dolostone reservoirs in a shallow water ramp under arid climatic conditions generally met the following conditions:(1) reefal beach deposits lay a foundation for reservoir development;(2) superficial conditions are an important determining factor for reservoir porosity; and(3) burial conditions provide environment for porosity preservation and modification.
基金Supported by the China Science and Technology Major Project(2017ZX05030-002)China National Petroleum Corporation Scientific Research and Technology Development Project(2019D-4309)
文摘Carboniferous carbonate reservoirs at the eastern edge of the Pre-Caspian Basin have undergone complex sedimentation,diagenesis and tectonism processes,and developed various reservoir space types of pores,cavities and fractures with complicated combination patterns which create intricate pore-throats structure.The complex pore-throat structure leads to the complex porosity-permeability relationship,bringing great challenges for classification and evaluation of reservoirs and efficient development.Based on the comprehensive analysis on cores,thin sections,SEM,mercury intrusion,routine core analysis and various tests,this paper systematically investigated the features and main controlling factors of pore-throats structure and its impact on the porosity-permeability relationship of the four reservoir types which were pore-cavity-fracture,pore-cavity,pore-fracture and pore,and three progresses are made.(1)A set of classification and descriptive approach for pore-throat structure of Carboniferous carbonate reservoirs applied to the eastern edge of the Pre-Caspian Basin was established.Four types of pore-throat structures were developed which were wide multimodal mode,wide bimodal mode,centralized unimodal mode and asymmetry bimodal mode,respectively.The discriminant index of pore-throat structure was proposed,realizing the quantitative characterization of pore-throat structure types.(2)The microscopic heterogeneity of pore reservoir was the strongest and four types of pore-throat structures were all developed.The pore-fracture and pore-cavity-fracture reservoirs took the second place,and the microscopic heterogeneity of pore-cavity reservoir was the weakest.It was revealed that the main controlling factor of pore-throat structure was the combination patterns of reservoir space types formed by sedimentation,diagenesis and tectonism.(3)It was revealed that the development of various pore-throat structure types was the important factor affecting poroperm relationship of reservoirs.The calculation accuracy of permeability of reservoirs can be improved remarkably by subdividing the pore-throat structure types.This study deepens the understanding of pore-throat structure of complicated carbonate reservoirs,and is conducive to classification and evaluation,establishment of precise porosity-permeability relationship and highly efficient development of carbonate reservoirs.
基金the International Cooperation Item of the National Natural Science Foundation of China (No. 30213009, 30310103007, 30410103150)Natural Science Foundation of Jiangsu Province of China (No. BK2007556)+1 种基金Basic Natura Science Foundation for Colleges and Universities Jiangsu Province (No. NK051039) the New Century Talent Project of Yangzhou University in China.
文摘This study is based on the Tong sheep obtained by the random sampling method of typical colonies in the central area of Baishui County in Shaanxi Province, China. An investigation was undertaken to clarify the gene constitution of blood protein and nonprotein types of Tong sheep. Twelve genetic markers were examined by starch-gel electrophoresis and cellulose acetate electrophoresis. Polymorphism in Tong sheep was found at the following 10 loci, transferrin (Tf), alkaline phosphatase (Alp), leucine aminopeptidase (Lap), arylesterase (Ary-Es), hemoglobin-β (Hb-β), X-protein (X-p), carbonic anhydrase (CA), catalase (Cat), malate dehydrogenase (MDH), and lysine (Ly), whereas, albumin (A1) and postalbumin (Po) loci were monomorphic. Genetic approach degree method and phylogenetic relationship clustering method were used to judge the origin and phylogenetic status of Tong sheep. Results from both methods maintained that Tong sheep belonged to the "Mongolia group", and Mongolia sheep was the origin of Tong sheep. This was also supported by the history of Tong sheep breeding. Compared to the phylogenetic relationship clustering method, the genetic approach degree method was more reliable for the extraction from East and South of Central Asia, and was more effective in reflecting the breeding course of Tong sheep.
文摘At present, the Tibetan Mastiff is the oldest and most ferocious dog in the world. However, the origin of the Tibetan Mastiff and its phylogenetic relationship with other large breed dogs such as Saint Bernard are unclear. In this study, the primers were designed accord- ing to the mitochondrial genome sequence of the domestic dog, and the 2,525 bp mitochondrial sequence, containing the whole sequence of Cytochrome b, tRNA-Thr, tRNA-Pro, and control region of the Tibetan Mastiff, was obtained. Using grey wolves and coyotes as out- groups, the Tibetan Mastiff and 12 breeds of domestic dogs were analyzed in phylogenesis. Tibetan Mastiff, domestic dog breeds, and grey wolves were clustered into a group and coyotes were clustered in a group separately. This indicated that the Tibetan Mastiff and the other domestic dogs originated from the grey wolf, and the Tibetan Mastiff belonged to Carnivora, Canidae, Canis, Canis lupus, Canis lupus familiaris on the animal taxonomy. In domestic dogs, the middle and small breed dogs were clustered at first; German Sheepdog, Swedish Elkhound, and Black Russian Terrier were clustered into one group, and the Tibetan Mastiff, Old English Sheepdog, Leonberger, and Saint Bernard were clustered in another group. This confirmed the viewpoint that many of the famous large breed dogs worldwide such as Saint Bernard possibly had the blood lineage of the Tibetan Mastiff, based on the molecular data. According to the substitution rate, we concluded that the approximate divergence time between Tibetan Mastiff and grey wolf was 58,000 years before the present (YBP), and the approximate divergence time between other domestic dogs and grey wolf was 42,000 YBP, demonstrating that the time of origin of the Tibetan Mastiff was earlier than that of the other domestic dogs.
文摘Comparing compositions of the fluid inclusions in volcanic rocks to the contents and isotopes of the gases in corresponding volcanic reservoirs using microthermometry, Raman microspectroscopy and mass spectrum analysis, we found that: (1) up to 82 mole% methane exists in the primary inclusions hosted in the reservoir volcanic rocks; (2) high CH4 inclusions recognized in the volcanic rocks correspond to CH4-bcaring CO2 reservoirs that are rich in helium and with a high ^3He/^4He ratio and which show reversed order of 813C in alkane; (3) in gas reservoirs of such abiotic methane (〉80%) and a mix of CH4 and CO2, the enclosed content of CH4 in the volcanic inclusions is usually below 42 mole%, and the reversed order of δ^13C in alkane is sometimes irregular in the corresponding gas pools; (4) a glassy inclusion with a homogeneous temperature over 900℃ also contains a small portion of CH4 although predominantly CO2. This affinity between gas pool and content of inclusion in the same volcanic reservoirs demonstrates that magma-originated gases, both CH4 and CO2, have contributed significantly to the corresponding gas pools and that the assumed hydrocarbon budget of the bulk earth might be much larger than conventionally supposed.
基金financially supported by Natural Science Foundation of China (No.41362007)The Research of Scientific Base of Typical Metal Mineral from the Ministry of Land and Resources (No.20091107)the Research Project on the Metallogenic Regularity of the Typical Strata Controlled Deposits of National Crisis Mines in Southwest China (No.20089943)
文摘Abundant organic inclusions are present in the Qinglong antimony deposit. However, the source rocks of these organic matters have not been reliably identified. Recently, a paleo--oil reservoir was found in the Qinglong antimony deposit. In view of similar components of gaseous hydrocarbon, we propose that the organic matters observed in inclusions in Qinglong antimony deposit would come from this paleo-oil reservoir. We used the Re-Os dating method to determine the age of the bitumen from this paleo-oil reservoir, and obtained an isochron age of 254.3~2.8 Ma. The age indicates that the oil- generation from source rock occurred in the early Late Permian, earlier than the Sb mineralization age (-148~8.5 Ma) in the Qinglong antimony deposit area. After oil generation from Devonian source rock, first and secondary migration, the crude oil have probably entered into the fractures and pores of volcanic rocks and limestone and formed a paleo-oil reservoir in the western wing of Dachang anticline. As burial process deepened, the crude oil has turned into natural gas, migrates into the core of Dachang anticline and formed a paleo-gas reservoir. The hydrocarbons (including CH4) in the reservoirs can serve as reducing agent to provide the sulfur required for Sb mineralization through thermal chemical reduction of sulfates. Therefore, the formation of oil-gas in the area is a prerequisite for the Sb mineralization in the Qinglong antimony deposit.
基金Supported by the National Natural Science Foundation of China(Nos.31670208,41871037,31800172)the Fund for Shanxi“1331 Project”。
文摘The genus Sheathia consists of over 20 species primarily distributed in Asia,Europe,Oceania,North America,and Africa.However,the origin and evolution of this genus remain unclear.Two gametophyte stage specimens(SAS18052 and SAS18523)and two“Chantransia”stage specimens(YTS19161 and YTS19017)were collected from Shanxi and Henan Provinces in China,respectively.Based on morphological data,isolates YTS19161 and YTS19017 were similar to Audouinella pygmaea,whereas the morphological characteristics of SAS18052 and SAS18523 were in good agreement with the circumscription description of S.longipedicellata.Molecular sequences of rbc L,COI-5P,and psb A were used to investigate the phylogenetic,evolutionary,and biogeographic origin of the genus Sheathia.The three molecular markers supported that the two gametophyte stage specimens belong to S.longipedicellata,while the isolates YTS19161 and YTS19017 were the“Chantransia”of S.longipedicellata.Ancestral area reconstruction and divergence time estimation speculated that Sheathia originated in North America,a portion of the Pangaea at approximately 328.07-184.73 million years ago(Ma).Our relaxed molecular clock analysis suggests that the Florideophyceae diverged approximately 741.04(894.36-631.70)Ma.The major divergences in this class involved the emergence of Nemaliophycidae[ca.662.01(779.83-580.51)Ma],and the split of orders Batrachospermales and Thoreales[ca.456.10(552.80-367.88)Ma].
文摘This paper utilizes multi-methods,such as core observation,slice identification,isotope analysis,trace element analysis,fluid inclusion technique and so on,to study the causes of the dolomite in the Nanpu Sag and the origins of the dolomite reservoir.The study results show that the forming environment of dolomite in the Nanpu Sag is a fresh-water lake environment,and the dolomite is the product of dolomitization which is caused by volcanic thermal fluids in the Early Dongying period.With the development of intergranular pores in the dolomitization process,a lot of dissolved pores/vugs and fractures were formed by denudation in the later periods because of the influence of thermal fluids including the associated fluids of volcanic activities and the expelled hydrocarbon fluids of the source rocks.On the whole,these secondary dissolution spaces greatly enhance the reservoir ability of the dolomite,and there are enough reservoir spaces in the dolomite in the Nanpu Sag.
基金Supported by the Knowledge Innovation Program of Chinese Academy of Sciences(KZCZ2-316)and Ecology and Environment Compensation Foundation from the Office of the TGP Construction commission of the State council of China(SX2001-021)
文摘Based on the five-year long dynamic tracking and investigation of the peasant households of the Lishu village, the influences by small town construction on the economy and employment of the original peasant households are discussed. On the one hand, small town construction plays a positive role in adjustment of the industrial structure of the original peasant households and in the transfer of their employment towards non-agricultural industries. On the other hand the economic growth of the original peasant households is not so well sustainable, and is so fluctuating. Moreover, the unbalance of income distribution of the said households has been furthered, and small town construction has made the existing labor surplus of the original peasant households more serious, particularly the women labor surplus.
基金This study was supported by the National Science and Technology Major Projects of China(Grant Nos.2016ZX05004006-001-002 and 2016ZX05004002-001)PetroChina Science and Technology Project(Grant No.2019B-0406)the China Scholarship Council(No.201908080005)。
文摘The Middle Ordovician subsalt Majiagou Formation in the Ordos Basin comprises pervasively dolomitized shallow marine limestone and is a major reservoir rich in natural gas resources.Four types of dolomite matrix and cement were identified based on petrographic textures:(very)finely crystalline,non-planar to planar-s matrix dolomite(Md1);finely to medium crystalline,planar-s to planar-e matrix dolomite(Md2);microbialites comprising dolomite microcrystals(Md3);and finely to coarsely crystalline dolomite cement(Cd).The Md1 and Md2 dolomites were controlled by alternating lagoon-shoal facies and haveδ13C values(−1.89 to+1.45‰VPDB for Md1,−1.35 to+0.42‰VPDB for Md2)that fall within or are slightly higher than the coeval seawater,suggesting the dolomitizing fluid of evaporated seawater.Md2 dolomite was then subjected to penecontemporaneous karstification by meteoric water and burial recrystallization by sealed brines during diagenesis,as indicated by its relatively lowerδ18O values(−8.89 to−5.73‰VPDB)and higher 87Sr/86Sr ratios(0.708920–0.710199).Md3 dolomite comprises thrombolite and stromatolite and is interpreted to form by a combination of initial microbial mediation and later replacive dolomitization related to evaporated seawater.Cd dolomite was associated with early-formed karst system in the Md2 host dolomite.The lowestδ18O values(−11.78 to−10.18‰VPDB)and 87Sr/86Sr ratios(0.708688–0.708725)and fluid inclusion data(Th:123–175°C)indicate involvement of hydrothermal fluid from which the Cd dolomite precipitated during deep burial.These results reveal the multi-stage dolomitization history of the Majiagou Formation and provide new constraints on fluid origins and dolomites evolution during deep burial in old superimposed basins,such as the Ordos Basin and elsewhere.
基金supported by the National Natural Science Foundation of China(No.41802179)Sichuan Science and Technology Program(No.2019YFH0037)the Foundation of the State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing(No.PRP/open-1906).
文摘Recently, significant oil discoveries have been made in the shallower pay zones of the Jurassic Badaowan Formation (J_(1)b) in the Mahu Sag, Junggar Basin, Northwest China. However, little work has been done on the geochemical characteristics and origins of the oil in the J_(1)b reservoir. This study analyzes 44 oil and 14 source rock samples from the area in order to reveal their organic geochemical characteristics and the origins of the oils. The J_(1)b oils are characterized by a low Pr/Ph ratio and high β-carotene and gammacerane indices, which indicate that they were mainly generated from source rocks deposited in a hypersaline environment. The oils are also extremely enhanced in C_(29) regular steranes, possibly derived from halophilic algae. Oil-source correlation shows that the oils were derived from the Lower Permian Fengcheng Formation (P_(1)f) source rocks, which were deposited in a strongly stratified and highly saline water column with a predominance of algal/bacterial input in the organic matter. The source rocks of the Middle Permian lower-Wuerhe Formation (P_(2)w), which were deposited in fresh to slightly saline water conditions with a greater input of terrigenous organic matter, make only a minor contribution to the J_(1)b oils. The reconstruction of the oil accumulation process shows that the J_(1)b oil reservoir may have been twice charged during Late Jurassic–Early Cretaceous and the Paleogene–Neogene, respectively. A large amount volume of hydrocarbons generated in the P_(1)f source rock and leaked from T_(1)b oil reservoirs migrated along faults connecting source beds and shallow-buried secondary faults into Jurassic traps, resulting in large-scale accumulations in J_(1)b. These results are crucial for understanding the petroleum system of the Mahu Sag and will provide valuable guidance for petroleum exploration in the shallower formations in the slope area of the sag.
基金Sponsored by:National Key Technology of China(2012BAJ15B00)Efficiency Optimization of Key Technology Research on High Urban Population Density Space(2012BAJ15B03)
文摘In the long-term symbiotic evolution process,the town areas along the Yangtze River and its natural and cultural landscapes have presented a sound "city-scene" landscape form. But with the implementation of the Three Gorges project,the town relocation as well as the flooding in the natural and human landscape area,the original harmonious "city-scene" pattern started to collapse and fell into the situation of "fragmentation" and "islanding". The differentiation between city and landscape,uncoordinated scale and fractured urban context become pressing issues that affect the integral form optimization of the town areas. This paper aims at responding to the call of the government about proceeding the construction of the Yangtze River economic belt under the ecological and green strategy and seeking an attuned "cityscene" relationship of the town area. Based on the analysis of the dynamic evolution of the "city-scene" relationship,the paper also pointed out that the urban construction around the reservoir area in the postThree Gorges era was the key stage of "scene-city" integration and symbiosis while the maintenance of scenery pattern,the harmony of space scale and the protection of living culture should be applied as the vital strategies.
文摘The olive is widely cropped in Tunisia where also oleaster trees thrive all around orchards and in natural sites. Little is known on the genetic relationships between the olive crop and oleaster trees in Tunisia. Fifty-two oleaster trees and fifteen cultivars were sampled from Tunisia. SSR genotyping was performed in polyacrylamide gels after fluorescent labeling. We used seven nuclear and two chloroplast SSR markers. AFC analyses showed close genetic relationships between cultivated and oleaster trees. Genetic relationships were also displayed in a dendrogram based on Unweighted Pair Group Method (UPGMA). Five clusters were defined mixing cultivar and oleaster trees suggesting close relationship between some cultivar and some oleaster trees. One oleaster is single in a cluster. The chlorotype SSR markers show probably three olive origins. Some cultivars have the CE chlorotype originates from the East of the Mediterranean basin, the CCK haplotype originates from Maghreb and the COM chlorotype originates from West Mediterranean. The cultivars were 1) introduced from the East;2) selected in the West;3) or selected in the North Africa region. The Tunisian oleaster trees carry eastern and western Mediterranean chlorotype CCK, COM and CE.
基金Supported the Major National Oil and Gas Projects of China(2016ZX05046-006).
文摘Origin of authigenic dolomites in the dolomitic reservoir of the Permian Fengcheng Formation in the Mahu Sag of Junggar Basin is unclear.Occurrence and genetic evolution of the authigenic dolomites in dolomitic rock reservoir of the Fengcheng Formation in the Mahu Sag were analyzed by polarized and fluorescence thin sections,scanning electron microscope(SEM),electron microprobe(EMP),C,O and Sr isotopes analysis,and other techniques.(1)Dolomites were mainly precipitated in three stages:penecontemporaneous-shallow burial stage(early stage of the Middle Permian),middle burial stage(middle stage of the Middle Permian),and middle-deep burial stage,with the former two stages in dominance.(2)Dolomitization fluid was high-salinity brine originating from alkaline lake.In the penecontemporaneous-shallow burial stage,Mg^(2+)was mainly supplied by alkaline-lake fluid and devitrification of volcanic glass.In the middle burial stage,Mg^(2+)mainly came from the transformation of clay minerals,devitrification of volcanic glass and dissolution of aluminosilicates such as feldspar.(3)Regular changes of Mg,Mn,Fe,Sr,Si and other elements during the growth of dolomite were mainly related to the alkaline-lake fluid,and to different influences of devitrification and diagenetic alteration of volcanic materials during the burial.(4)In the penecontemporaneous stage,induced by alkaline-lake microorganisms,the micritic-microcrystalline dolomites were formed by primary precipitation,replacement of aragonite and high-Mg calcite,and other processes;in the shallow burial stage,the silt-sized dolomites were formed by continuous growth of micritic-microcrystalline dolomite and replacement of calcites,tuffs and other substances;in the middle burial stage,the dolomites,mainly silt-and fine-sized,were formed by replacement of volcanic materials.The research results are referential for investigating the formation mechanism and distribution patterns of tight dolomitic reservoirs in the Mahu Sag and other similar oil and gas bearing areas.
基金Supported by NSFC project No. 40372066 and SRFDP No. 20030183042
文摘Methane-rich fluids were recognized to be hosted in the reservoir volcanic rocks as primary inclusions. Samples were collected from core-drillings of volcanic gas reservoirs with reversed δ13C of alkane in the Xujiaweizi depression of the Songliao Basin. The volcanic rocks are rhyolite dominant being enriched in the more incompatible elements like Cs, Rb, Ba, Th, U and Th with relative high LREE, depleted HREE and negative anomalies of Ti and Nb, suggesting a melt involving both in mantle source and crustal assimilation. Primary fluids hosted in the volcanic rocks should have the same provenance with the magma. The authors concluded that the enclosed CH4 in the volcanics are mantle/magma-derived alkane and the reversed δ13C of alkane in the corresponding gas reservoirs is partly resulted from mixture between biogenic and abiogenic gases.
基金co-supported by the National Basic Research Program of China(Grant No.2011CB201103)the National Science and Technology Major Project(Grant No.2011ZX05004003)
文摘Secondary storage spaces with very complex geometries are well developed in Ordovician carbonate reservoirs in the Tarim Basin,which is taken as a study case in this paper.It is still not clear how the secondary storage space shape influences the P-& S-wave velocities (or elastic properties) in complex carbonate reservoirs.In this paper,three classical rock physics models (Wyllie timeaverage equation,Gassmann equation and the Kuster-Toks z model) are comparably analyzed for their construction principles and actual velocity prediction results,aiming at determining the most favourable rock physics model to consider the influence of secondary storage space shape.Then relationships between the P-& S-wave velocities in carbonate reservoirs and geometric shapes of secondary storage spaces are discussed from different aspects based on actual well data by employing the favourable rock physics model.To explain the influence of secondary storage space shape on V P-V S relationship,it is analyzed for the differences of S-wave velocities between derived from common empirical relationships (including Castagna's mud rock line and Greenberg-Castagna V P-V S relationship) and predicted by the rock physics model.We advocate that V P-V S relationship for complex carbonate reservoirs should be built for different storage space types.For the carbonate reservoirs in the Tarim Basin,the V P-V S relationships for fractured,fractured-cavernous,and fractured-hole-vuggy reservoirs are respectively built on the basis of velocity prediction and secondary storage space type determination.Through the discussion above,it is expected that the velocity prediction and the V P-V S relationships for complex carbonate reservoirs should fully consider the influence of secondary storage space shape,thus providing more reasonable constraints for prestack inversion,further building a foundation for realizing carbonate reservoir prediction and fluid prediction.
文摘Natural gases of shallow reservoirs with the carbon isotopic compositions of methane ranging from -50‰ to -60‰ (PDB) were considered as mixed gases of biogenic and thermogenic origins previously and some of them were considered as low-mature (or low temperature thermogenic) gases lately. In this paper natural gases with the carbon isotopic compositions of methane in the above range were identified using the molecular and stable carbon isotopic compositions of methane, ethane and propane. The mixed gases of biogenic and mature thermogenic origins display the characteristics of {δ{}+{13}C-1} ranging from -50‰ to -60‰, {δ{}+{13}C-2}>-35‰, Δ values ({δ{}+{13}C-3}-{δ{}+{13}C-2})< 5‰ and C-1/∑C++-2 ratios < 40. Immature to low|mature gases display the characteristics of {δ{}+{13}C-1} ranging from -50‰ to -60‰, {δ{}+{13}C-2} < -40‰, Δ values ({δ{}+{13}C-3}-{δ{}+{13}C-2}) >7‰, and C-1/∑C++-2 ratios >60.