Research on crustal structure and lithosphere property in the Okinawa Trough area

A mass of geological, geophysical and geochemical data and information from the Okinawa Trough area are collected for comprehensive research in the study area from East China to Okinawa Trough and then to Ryukyu Island Are region. According to the seismic tomography result (P and S wave) and the processing result of free-air and Bouguer gravity anomaly and magnetic anomaly data in the study area, the comprehensive interpretation is carried out. The Moho depth distribution of the study area is obtained by the inversion calculation based on gravity data using the Harmonious Series method. The crust properties are analyzed. Meantime, some Cenozoic basalt data from Kuandian (NE China), Hannuoba (North China), Minxi (South China), Penghu Islands (Taiwan Strait), Okinawa Trough and Japan Island Arc regions are chosen to make the comparison research on element- isotopes. The result indicates that the lithosphere thickness in the Okinawa Trough area has obviously decreased, where a Low -velocity layer of upper-mantle has reached the Moho interface and the metasometized asthenosphere has formed. The research result on element- isotopes shows that the characteristic of the crust in the Okinawa Trough area is different from that in East China area and the Ryukyu Island Arc area. It is considered that the crust in the Okinawa Trough area belongs to the transition type, which is quite similar to the feature of the oceanic crust.

Simultaneous determination of four phases of copper in geological samples

According to the specific property of respective phases in copper ore, optimal extracting condition for, tour phases of copper with five infusion was examined. After a series of experiments, for example, different weight Of sample, artificial mixed single phases sample and repeated experiment, the extracting ratio constants foil all phases in different infusions were obtained. The mathematical model which is on the basis of the stable extracting constant is established. Based on the purpose-control genetic algorithms, we only need to determine the total copper in the sample in different infusions under the selected condition, then the value of respective phase could be calculated. The-relative standard deviation are (%) free oxidized copper phase:1.5, conjunction oxidized copper phase: 17.6,, secondary copper sulfide phase: 1.9, primary copper sulfide phase : 2.7,total copper: 0.8.

Molecular cloning, expression and biochemical property analysis of AtKP1, a kinesin gene from Arabidopsis thaliana

Kinesins are common in a variety of eukaryotic cells with diverse functions. A cDNA encoding a member of the Kinesin-14B subfamily is obtained using X-RACE technology and named AtKP1 (for Arabidopsis kinesin protein 1). This cDNA has a maximum open reading frame of 3.3 kb encoding a polypeptide of 1087 aa. Protein domain analysis shows that AtKP1 contains the motor domain and the calponin homology domain in the central and amino-terminal regions, respectively. The carboxyl-terminal region with 202 aa residues is diverse from other known kinesins. Northern blot analysis shows that AtKP1 is widely expressed at a higher level in seedlings than in mature plants. 2808 bp of the AtKP1 promoter region is cloned and fused to GUS. GUS expression driven by the AtKP1 promoter region shows that AtKP1 is mainly expressed in vasculature of young organs and young leaf trichomes, indicating that AtKP1 may participate in the differentiation or development of Arabidopsis thaliana vascular bundles and trichomes. A truncated AtKP1 protein containing the putative motor domain is expressed in E. coli and affinity-purified. In vitro characterizations indicate that the polypeptide has nucleotide-dependent microtubule-binding ability and microtubule-stimulated ATPase activity.

Ecological basis of Alpine meadow ecosystem management in Tibet: Haibei Alpine Meadow Ecosystem Research Station

Alpine meadow and shrub are the main pasture types on the Tibetan Plateau, and they cover about 35% of the total land area. In order to understand the structural and functional aspects of the alpine ecosystem and to promote a sustainable animal production system, the Haibei Alpine Meadow Research Station was established in 1976. A series of intensive studies on ecosystem structure and function, including the energy flow and nutrient cycling of the ecosystem, were the main tasks during the first 10 years. Meanwhile, studies with 5 different grazing intensities on both summer and winter pasture have been conducted. In the early years of the 1990s, the research station started to focus its research work on global warming, biodiversity and sustainable animal production systems in pastoral areas. Various methods for improving degraded pasturelands have been developed in the region.

Bézier曲线间最近距离的计算方法

针对Bzier曲线间最近距离计算问题,提出一种简捷、可靠的计算方法.该方法以Bernstein多项式算术运算为工具,建立Bzier曲线间最近距离的计算模型;然后充分利用Bzier曲面的凸包性质和de Casteljau分割算法进行求解.该方法几何意义明确,能有效地避免迭代初始值的选择和非线性方程组的求解,并可进一步推广应用于计算Bzier曲线/曲面间的最近距离.实验结果表明,该方法简捷、可靠且容易实现,与Newton-Raphson方法的融合可进一步提高该方法的运行速度.

黄骅坳陷马东地区沙河街组重力流水道储层评价及剩余油研究

In this paper, taking Madong district of Huanghua depression as a case, based on the theory of sequence stratigraphy, sedimentology, reservoir geology and geophysics, according to core analysis, seismic attribute analysis, logging constrained inversion, multi-data correlation of strata, reservoir modeling, etc. the lower and middle first member of Shahejie formation of the study area was forecasted and evaluated. As a result, a number of reservoir prediction and remaining oil distribution methods suitable to oil exploitation of gravity flow channel reservoir are presented. Scientific foundation is provided to the next adjustment of development program and exploitation of the remaining oil. According to high resolution sequence stratigraphy theory, precise stratigraphic framework was founded, the facies types and facies distribution were studied under the control of stratigraphic framework, the technologies of seismic attribute abstraction and logging constrained inversion. Result shows that gravity flow channel, as the main facies, developed in the rising period of base-level cycle, and it was formed during the phase of contemporaneous fault growth. As the channel extends, channel width was gradually widened but thickness thined. The single channels were in possession of a great variety of integrated modes, such as isolated, branching off, merging and paralleling, forming a kind of sand-mud interblending complex sedimentary units. Reservoir quality differs greatly in vertical and horizontal direction, and sedimentary microfacies is main controlling factor of the reservoir quality. In major channel, deposition thickness is great, and petrophysical property is well. While in marginal channel, reservoir is thinner, and petrophysical property is unfavorable. Structure and reservoir quality are main factors which control the oil and gas distribution in the study area. On the basis of the research about the reservoir quality, internal, planar and 3-D reservoir heterogeneities are characterized, and the reservoir quality was sorted rationally. At last, based on the research of reservoir numerical simulation of key well group, combined with reservoir performance analysis and geological analysis above, remaining oil distribution patterns controlled by internal rhythm of gravity flow channel were set up. Through this research, a facies-restrained reservoir prediction method integrating multi-information was presented, and potential orientation of remaining oil distribution in gravity flow channel reservoir is clarified.

残留盆地分布综合地球物理研究——以大港地区为例

Macro-distribution of residual basins is a basic question in residual basin research，the main object of macro-distribution study is to build strata framework, compute thickness of residual strata and analyze characteristics of residual basins. With the guidance of the theory of integrated geology and geophysical research, the paper assembled series of methods and established the technical chart based on gravity and magnetic data, with restriction of geology, seismic and drilling data. Based on potential field data processing and analysis, forward and inverse computation, region potential field analysis and potential field separation, etc. it computed depth of gravity/magnetic basement and got strata framework. It had got effective results in the research of macro-distribution of residual basin research in the Dagang area. It did the wavelet transform of gravity/magnetic data with multi-kind of wavelet basis using a trou algorithm. From comparison of processing result and their spectral of wavelet analysis, up continuation and filter method, the wavelet approximation is better to fit the regional potential field, and it is an effective method to separate gravity/magnetic effect caused by deep geology bodies. The experiment of matching pursuit shows that te transform domain methods have great advantage in potential data analysis. From the integrated geophysical study of rock property study, gravity/magnetic basement inversion and fault system analysis of the Dagang area, it gets the strata framework and the thickness of pre-Cenozoic residual strata. Comprehensive study with gravity and magnetotelluric profile inversion and interpretation, three prospect plays of macro-distribution of residual basins are fingered out. It has great residual strata thickness in the northern part of Chengning Uplift and there is thrust fault in the deep zone and good up-Paleozoic hydrocarbon source rocks in this area. With integrated analysis, this area will be the most prospective hydrocarbon location of pre-Cenozoic residual basins.

渤海湾盆地前第三系构造演化与煤成气成藏研究

The disequilibrium between supply and demand the east part of North China accelerated natural gas exploration in Bohai bay basin. Exploration practice showed that coal-derived gas is important resource. In searching of big to middle scaled coal derived gas field, and realize successive gas supply, the paper carried out integrated study on structural evolution of Pre-Tertiary and evaluation of reservoir forming condition of coal-derived gas. Study work of the paper was based on the following condition: available achievement in this field at present, good understanding of multiphase of tectonic movement. Study work was focused on geological evolution, source rock evaluation and dissection key factors controlling reservoir forming. Based on analysis of seismic data, drilling data, tectonic style of Pre-Tertiary was subdivided, with different tectonic style representing different tectonic process. By means of state of the art, such as analysis of balanced cross section, and erosion restoration, the paper reestablished tectonic history and analyzed basin property during different tectonic phase. Dynamic mechanism for tectonic movement and influence of tectonic evolution on tectonic style were discussed. Study made it clear that tectonic movement is intensive since Mesozoic including 2 phase of compressional movement (at the end of Indo-China movement, and Yanshan movement), 2 phase of extensional movement (middle Yanshan movement, and Himalayan movement), 2 phase of strike slip movement, as well as 2 phase of reversal movement (early Yanshan movement, and early Himalayan movement). As a result, three tectonic provinces with different remnant of strata and different tectonic style took shape. Based on afore mentioned study, the paper pointed out that evolution of Bohai bay basin experienced the following steps: basin of rift valley type (Pt2+3)-craton basin at passive continental margin (∈1－2)-craton basin at active continental margin (∈3- O)-convergent craton basin (C-T1+2)-intracontinental basin (J＋K). Superposition of basins in different stage was discussed. Aimed at tectonic feature of multiple phases, the paper put forward concept model of superposition of tectonic unit, and analyzed its significance on reservoir forming. On basis of the difference among 3 tectonic movements in Mesozoic and Cenozoic, superposition of tectonic unit was classified into the following 3 categories and 6 types: continuous subsidence type (I), subsidence in Mesozoic and uplift for erosion in Cenozoic (II1), repeated subsidence and uplift in Mesozoic and subsidence in Cenozoic (II2), repeated subsidence and uplift in Mesozoic and uplift for erosion in Cenozoic (II3), uplift for erosion in Mesozoic and subsidence in Cenozoic (II4), and continuous uplift (III). Take the organic facies analysis as link, the paper established relationship between sedimentary environment and organic facies, as well as organic facies and organic matter abundance. Combined information of sedimentary environment and logging data, the paper estimated distribution of organic matter abundance. Combined with simulation of secondary hydrocarbon generation, dynamic mechanism of hydrocarbon generation, and thermal history, the paper made static and dynamic evaluation of effective source rock, i.e. Taiyuan formation and Shanxi formation. It is also pointed out that superposition of tectonic unit of type II2, type II4, and type I were the most favorable hydrocarbon generation units. Based on dissection of typical primary coal-derived gas reservoir, including reservoir forming condition and reservoir forming process, the paper pointed out key factors controlling reservoir forming for Carboniferous and Permian System: a. remnant thickness and source rock property were precondition; b. secondary hydrocarbon generation during Himalayan period was key factor; c. tectonic evolution history controlling thermal evolution of source rock was main factor that determine reservoir forming; d. inherited positive structural unit was favorable accumulation direction; e. fault activity and regional caprock determined hydrocarbon accumulation horizon. In the end, the paper established reservoir forming model for different superposition of tectonic units, and pointed out promising exploration belts with 11 of the first class, 5 of the second class and 6 of the third class.

油气勘探风险评价与决策技术研究

PetroChina and other national petroleum incorporations need rigorous procedures and practical methods in risk evaluation and exploration decision at home and abroad to safeguard their international exploration practice in exploration licence bidding, finding appropriate ratio of risk sharing with partners, as well as avoiding high risk projects and other key exploration activities. However, due to historical reasons, we are only at the beginning of a full study and methodology development in exploration risk evaluation and decision. No rigorous procedure and practical methods are available in our exercises of international exploration. Completely adopting foreign procedure, methods and tools by our national incorporations are not practical because of the differences of the current economic and management systems in China. The objective of this study is to establish a risk evaluation and decision system with independent intellectual property right in oil and gas exploration so that a smooth transition from our current practice into international norm can take place. The system developed in this dissertation includes the following four components: 1. A set of quantitative criteria for risk evaluation is derived on the basis of an anatomy of the parameters from thirty calibration regions national wide as well as the characteristics and the geological factors controlling oil and gas occurrence in the major petroleum-bearing basins in China, which provides the technical support for the risk quantification in oil and gas exploration. 2. Through analysis of existing methodology, procedure and methods of exploration risk evaluation considering spatial information are proposed. The method, utilizing Mahalanobis Distance (MD) and fuzzy logic for data and information integration, provides probabilistic models on the basis of MD and fuzzy logic classification criteria, thus quantifying the exploration risk using Bayesian theory. A projection of the geological risk into spatial domain provides a probability map of oil and gas occurrence in the area under study. The application of this method to the Nanpu Sag shows that this method not only correctly predicted the oil and gas occurrence in the areas where Beibu and Laoyemiao oil fields are found in the northwest of the onshore area, but also predicted Laopu south, Nanpu south and Hatuo potential areas in the offshore part where exploration maturity was very low. The prediction of the potential areas are subsequently confirmed by 17 exploration wells in the offshore area with 81% success, indicating this method is very effective for exploration risk visualization and reduction. 3. On the basis of “Methods and parameters of economic evaluation for petroleum exploration and development projects in China”, a ”pyramid” method for sensitivity analysis was developed, which meets not only the need for exploration target evaluation and exploration decision at home, but also allows a transition from our current practice to international norm in exploration decision. This provides the foundation for the development of a software product “Exploration economic evaluation and decision system of PetroChina” (EDSys). 4. To solve problem in methodology of exploration decision, effort was made on the method of project portfolio management. A drilling decision method was developed employing the concept of geologically risked net present value. This method overcame the dilemma of handling simultaneously both geological risk and portfolio uncertainty, thus casting light into the application of modern portfolio theory to the evaluation of high risk petroleum exploration projects.

砂砾岩油藏精细油藏描述–以准噶尔盆地西北缘八区下乌尔禾组油藏为例

Glutenite reservoir is one of the most important reservoir types in china. Because of its particularity of rock structure and pore structure, it is usually difficult in development, especially for its serious heterogeneity. On the basis of seismic, well logs, core data and production performance, the lower Wuerhe group can be divided into one second-order sequences, two third-order sequences and twenty two subsequences, corresponding to the five stages and twenty two minlayers. In addition, the fault systems are interpreted and the control action of fault systems to reservoir development is also described. The lower Wuerhe formation of 8th district belongs to fluvial-dominated fan delta sedimentation, according to the analysis of well logs, logging data and core data. It can be subdivided into two kinds of subfacies and nine kinds of microfacies. The fan delta plain subfacies mainly consist of braided channel, unconcentrated flow, mud flow and sieve deposit microfacies. The fan delta front subfacies include subaqueous distributary channel, subaqueous interdistributary channel, debris flow, subaqueous barrier and grain flow microfacies. Combined with the regional geological characteristics, the porosity model of lower Wuerhe formation is performed using core data. A permeability model based on the flow zone index is also formed according to the pore throat characteristics and flow property. Finally, the heterogeneity is analyzed. The result shows that the lower Wuerhe formation has a feature of middle-high heterogeneity, and it is controlled by material sources and sedimentary facies belt.

鄂尔多斯盆地子洲气田二叠系山西组储层特征与天然气富集规律研究

In this thesis, detailed studies on the sedimentology and petrophysical properties of reservoir rocks in the Shan#2 Member of Shanxi Formation, Zizhou gas field of Ordos Basin, are carried out, based on outcrop description, core description, wireline log interpretation and analysis of petrophysical properties. In the context of stratigraphic division scheme of the Upper Paleozoic in Ordos Basin, the Shan#2 Member is further divided into three subintervals: the Shan#23, Shan#22 and Shan#21, based on the marker beds，depositional cycles, wireline log patterns. Subaqueous deltaic-front distributary channels, distributed from the south to north, is identified，which is the main reservoir sand bodies for gases of Shan#2 Member at Zizhou gas field. Quartzose and lithic-quartzose sandstones, commonly with a high volume of cement, but a low volume of matrix, are the major reservoir rocks in the studied area. All sandstones have been evolved into the late diagenetic stage (referred to as diagenetic stage B) during the burial, experiencing compaction, cementation, replacement and dissolution, in which the compaction and cementation could have reduced the porosity, while dissolution could have improved the petrophysical properties. The pore types in the reservoirs are dominated by intergranular-solutional, intergranular-intercrystal and intercrystal-solutional porosity. According to the parameters and capillary pressure curves of test samples, five types of pore texture (I-V) are differentiated, in which types II and III pore textures displayed by low threshold pressure-wide pore throat and moderate threshold pressure-moderately wide pore throat, exist widespread. Sandstone reservoirs in the studied area are characterized by exceptionally low porosity and permeability, in which the petrophysical properties of those in Shan#23 horizon are relatively better. The petrophysical property of reservoirs was influenced both by the sedimentation and diagenesis. In general, the coarse quartzose sandstones deposited in subaqueous distributary channels show the best petrophysical property, which tends to be worse as the grain size decreases and lithic amount increases. Three types of gas reservoirs in Shan#23 horizon are classified according to petrophysical properties (porosity and permeability), which could have been influenced by the initial depositional facies, diagenesis and tectonics. On the basis of the study on the geological conditions of reservoirs in the area, it is concluded that sedimetary facies, diagenesis and tectonic actions can provide an important foundation for gas pool formation, which can also control the accumulation and distribution of gas reservoirs.

鄂尔多斯盆地陇东地区长8段砂岩输导体定量表征研究

Migration carriers act as the “Bridges” connecting source rock and traps and play important roles in petroleum migration and accumulation system. Among various types of carriers, sandstone carrier constitutes the basis of carrier system consisting of connected sandstone bodies, of sand-bodies connected with other carriers, such as faults and/or unconformities. How do we understand sandstone carrier beyond the traditional reservoirs concept? How could we characterize quantitatively this kind of carriers for petroleum migration? Such subjects are important and difficult contents in dynamic studies on hydrocarbon migration and accumulation. Sandstone carrier of Chang 8 member in Longdong area of Ordos Basin is selected as the research target in this thesis. Through conducting integrated reservoir analysis on many single wells, the correlation between single sandstone thickness and oil thickness seems good. Sketch sandstone is defined in this thesis as the principal part of carrier based on systematical analysis on lithology and sandstone thickness. Geometry connectivity of sandstone bodies was identified by the spatial superposition among them and was proved by the oil property features in oilfields. The connectivity between sandstone carriers is also hydrodynamically studied by observing and analyzed various diagenetic phenomena, especially the authigenic minerals and their forming sequence. The results were used to characterize transporting capability of sandstone carriers during the key petroleum migration periods. It was found that compaction and cementation are main causes to reduce pore space, and resolution may but not so importantly increases pore space after the occurrence of first migration. The cements of ferrocalcite and kiesel seem like the efficient index to demonstrate the hydraulic connection among sandy bodies. Diagenetic sequence and its relationship with petroleum migration phases are analyzed. Sandstone carrier of Chang 8 member was then characterized by studying their pore space and permeable properties. The results show an average porosity and permeability of Chang 8 carriers are respectively 8% and 0.50md, belongs to low porosity - low permeability reservoirs. Further, the physical properties of Chang 81 member are commonly better than those of Chang 82 member. Methods to reconstruct property of sandstone carrier during petroleum migration phase (late Jurassic) are built based on diagenetic sequence. Planal porosity, porosity and permeability of sandstone carrier in this period are statistically analyzed. One combining index - product of thickness and ancient porosity - is selected as the idea parameter to characterize sandstone carrier of late Jurassic after contrast with other parameters. Reservoirs of Chang 8 member in Longdong area are lithological reservoir controlled by sand body in which oil layers in middle part are clamped with dry layers in upper and lower parts, in a sandwich way. Based a newly proposed “migration-diagensis-remigration” model in low permeability sandstone of Chang 8 member in Longdong area, oil migration and accumulation processes during different periods are simulated with the reconstructed sandstone carriers system. Results match well with current reservoir distributions. Finally, suggestions for next favorable exploration areas are given based on all research achievements.

酒泉盆地酒东坳陷下白垩统储层特征及有利勘探方向研究

Jiuquan basin, located in the middle of the Hexizoulang, is one of the major important Mesozoic、cenozoic oil-gas bearing basin in the west of China. Jiuquan basin is composed of Jiuxi depression、Huahai-jinta depression and Jiudong depression. Basement of Jiudong depression is Silurian shallow metamorphic rock. Ying-er sag , focus of this study, is the biggest sag in Jiudong depression and the targeting study object is cretacic strata. Structure evolution and geological background were carefully studied in this research. A series of methods were applied to this research: values of oxygen and carbon isotope and trace elements analysis were used to recover salinity of the palae-lake water of the sag. The evolution and distribution of sedimentary faces were carefully studied. Also, various analysis and tests were made to study the diagenesis of the reservoir sandstones、porosity evolution and porosity distribution. All the studies indicate that sedimentary faces are main macroscopic factor controlling the reservoir quality; Compaction is the main factor destroying reservoir property. Carbonate cements greatly preserved the porosity in eodiagenesis because it had prevented significant early mechanical compaction and its dissolution in the late diagenesis generated secondary pores. Carbonate cements in the late diagenesis occluded primary porosity and played a negative role in the porosity preservation. Source of the carbonate cements were also preliminarily discussed. Feldspar grains and lithic fragments were dissolved by acid fluid and formed a great amount of secondary pores and developed the reservoir quality. Also, sedimentary-diagenesis zones were identified. On basis of these studies, Reservoir forming factors were studied. Keywords: Jiudong depression, sedimentary faces，reservoirs diagenesis reservoir evaluation，secondary pores

粘弹性介质中的地震波传播与波形反演研究

The real earth is far away from an ideal elastic ball. The movement of structures or fluid and scattering of thin-layer would inevitably affect seismic wave propagation, which is demonstrated mainly as energy nongeometrical attenuation. Today, most of theoretical researches and applications take the assumption that all media studied are fully elastic. Ignoring the viscoelastic property would, in some circumstances, lead to amplitude and phase distortion, which will indirectly affect extraction of traveltime and waveform we use in imaging and inversion. In order to investigate the response of seismic wave propagation and improve the imaging and inversion quality in complex media, we need not only consider into attenuation of the real media but also implement it by means of efficient numerical methods and imaging techniques. As for numerical modeling, most widely used methods, such as finite difference, finite element and pseudospectral algorithms, have difficulty in dealing with problem of simultaneously improving accuracy and efficiency in computation. To partially overcome this difficulty, this paper devises a matrix differentiator method and an optimal convolutional differentiator method based on staggered-grid Fourier pseudospectral differentiation, and a staggered-grid optimal Shannon singular kernel convolutional differentiator by function distribution theory, which then are used to study seismic wave propagation in viscoelastic media. Results through comparisons and accuracy analysis demonstrate that optimal convolutional differentiator methods can solve well the incompatibility between accuracy and efficiency, and are almost twice more accurate than the same-length finite difference. They can efficiently reduce dispersion and provide high-precision waveform data. On the basis of frequency-domain wavefield modeling, we discuss how to directly solve linear equations and point out that when compared to the time-domain methods, frequency-domain methods would be more convenient to handle the multi-source problem and be much easier to incorporate medium attenuation. We also prove the equivalence of the time- and frequency-domain methods by using numerical tests when assumptions with non-relaxation modulus and quality factor are made, and analyze the reason that causes waveform difference. In frequency-domain waveform inversion, experiments have been conducted with transmission, crosshole and reflection data. By using the relation between media scales and characteristic frequencies, we analyze the capacity of the frequency-domain sequential inversion method in anti-noising and dealing with non-uniqueness of nonlinear optimization. In crosshole experiments, we find the main sources of inversion error and figure out how incorrect quality factor would affect inverted results. When dealing with surface reflection data, several frequencies have been chosen with optimal frequency selection strategy, with which we use to carry out sequential and simultaneous inversions to verify how important low frequency data are to the inverted results and the functionality of simultaneous inversion in anti-noising. Finally, I come with some conclusions about the whole work I have done in this dissertation and discuss detailly the existing and would-be problems in it. I also point out the possible directions and theories we should go and deepen, which, to some extent, would provide a helpful reference to researchers who are interested in seismic wave propagation and imaging in complex media.