费尔干纳盆地油气资源潜力与勘探新领域

费尔干纳盆地是中亚地区的一个老油区,虽然经过了多年的勘探和开发,但仍有较大的资源潜力。主要勘探新领域有：寻找非构造油气藏（隐蔽油气藏）、老油田内部滚动勘探、钻探古中生界深层。费尔干纳盆地此前的钻探目标均是围绕大构造背景上的背斜圈闭进行,非背斜构造的研究和钻探很少。笔者研究认为费尔干纳盆地寻找非背斜圈闭油藏前景广阔;在对老油田内部钻采、试油资料的详细分析后,认为老油田内部主力逆断层的下盘和背斜构造的侧翼具有较大的资源潜力;盆地的古中生界不仅可以新生古储,而且其本身也可以生油,在盆地局部隆起及边部都存在古中生界成藏的条件。     

青藏高原北部新生代陆相盆地石油地质条件及勘探前景

青藏高原北部陆相盆地中烃源岩发育层位包括始新统风火山组、渐新统雅西措组和中新统五道梁组。古近系雅西措组烃源岩,特别是灰岩属于中好烃源岩范畴,有机质类型较好,且烃源岩主体处于成熟阶段,是藏北高原新生代陆相盆地主力烃源岩的发育层位。陆相盆地储集岩较发育,储层较丰富,发育层位包括风火山组和雅西措组,其中雅西措组是储层主力分布层位。对测区分析数据表明：通天河盆地具备一定规模的生油岩厚度,而且有机质丰度为沱沱河地区最高,表明其勘探前景较好。     

人工边坡潜在滑动面研究——以广州科学城某人工高边坡为例

运用强度参数的改变对边坡破坏面形迹影响不明显这一特点,在数值模拟过程中通过改变岩体强度参数,有效地获取潜在滑动面的位置和形态,较好地解决了滑动面搜索的难题。将该法应用于广州科学城某人工高边坡稳定性的研究,在三维数值模拟过程中,将强度参数大幅度折减,计算后获得各剖面的剪应变增量图,从这些图中可获得潜在滑动面。这与人们通常将此类边坡的中风化面作为滑动面存在较大差别。将该滑动面运用极限平衡法进行计算,计算结果显示各剖面的安全系数基本都大于1.2,边坡稳定但仍需要加固处理,与三维数值模拟结果相一致。由此认为用这种分析法确定出的潜在滑动面合理、计算结果可靠,可作为搜索边坡潜在滑动面并计算安全系数的方法之一。     

Non-Linear Theory and Power-Law Models for Information Integration and Mineral Resources Quantitative Assessments

Singular physical or chemical processes may result in anomalous amounts of energy release or mass accumulation that, generally, are confined to narrow intervals in space or time. Singularity is a property of different types of non-linear natural processes including cloud formation, rainfall, hurricanes, flooding, landslides, earthquakes, wildfires, and mineralization. The end products of these non-linear processes can be modeled as fractals or multifractals. Hydrothermal processes in the Earth’s crust can result in ore deposits characterized by high concentrations of metals with fractal or multifractal properties. Here we show that the non-linear properties of the end products of singular mineralization processes can be applied for prediction of undiscovered mineral deposits and for quantitative mineral resource assessment, whether for mineral exploration or for regional, national and global planning for mineral resource utilization. In addition to the general theory and framework for the non-linear mineral resources assessment, this paper focuses on several power-law models proposed for characterizing non-linear properties of mineralization and for geoinformation extraction and integration. The theories, methods, and computer system discussed in this paper were validated using a case study dealing with hydrothermal Au mineral potential in southern Nova Scotia, Canada.     

ELECTROCHEMICAL MEASUREMENT OF STEEL CORROSION IN SEABOTTOM SEDIMENT WITH “MD” METHOD

The tbough one year cormsion potential and polarisation resistanoc for 3 kinds of stals in seabottomedment of Liaodong Bay were measured with the “MD” method.The measurements wiIl have some thoretical and pndital talues. The thooretical valoc lies in thatthe reoorded changing process of the practital corrosion case can be basis for indoor discussion andeectrochemical on the corrosion practical value lies in that the obtained datu canbe basis for designing and controlling elatrochemical protation syttems. In fact, it is very difficult tomeasure in situ the cornosion parnders of steeIs in sea sediment.     

On the tidal variation of the geopotential

In this paper analytical expressions are derived for the temporal variations ofJ ₂ andJ ₂₂ due to the tides of the solid Earth, taking into account only the deformation of the mantle, and employing a procedure already used by the authors in their Hamiltonian theory of the Earth's rotation, which obtain the necessary parameters in a direct way by integration of those provided by a selected model of Earth interior.Numerical tables giving the periodic variation of coefficients are given, as well as a new prediction for UT1. For J ₂ and J ₂₂ the amplitudes reach such a magnitude that both two variations should not be ignored in studies involving the analysis of highly precise satellite tracking data. Moreover, the possibility of improving our knowledge of the value of those harmonic coefficients in only a more exact digit appears as to be strongly dependent on the limitations in the theoretical modeling of the variations of the inertia tensor due to solid tides.     

On Szebehely's problem for holonomic systems involving generalized potential functions

We consider the problem of finding the generalized potential function V = U _i(q ¹, q ²,..., q ⁿ)q ⁱ + U(q ¹, q ²,...;q ⁿ) compatible with prescribed dynamical trajectories of a holonomic system. We obtain conditions necessary for the existence of solutions to the problem: these can be cast into a system of n – 1 first order nonlinear partial differential equations in the unknown functions U ₁, U ₂,...;, U _n, U. In particular we study dynamical systems with two degrees of freedom. Using adapted coordinates on the configuration manifold M ₂ we obtain, for potential function U(q ¹, q ²), a classic first kind of Abel ordinary differential equation. Moreover, we show that, in special cases of dynamical interest, such an equation can be solved by quadrature. In particular we establish, for ordinary potential functions, a classical formula obtained in different way by Joukowsky for a particle moving on a surface.Work performed with the support of the Gruppo Nazionale di Fisica Matematica (G.N.F.M.) of the Italian National Research Council.     

The hydrogeochemistry of methane: Evidence from English groundwaters

The presence of methane (CH₄) in groundwater is usually only noticed when it rises to high concentrations; to date rather little is known about its production or natural ‘baseline’ conditions. Evidence from a range of non-polluted groundwater environments in England, including water supply aquifers, aquicludes and thermal waters, reveals that CH₄ is almost always detectable, even in aerobic conditions. Measurements of potable waters from Cretaceous, Jurassic and Triassic carbonate and sandstone aquifers reveal CH₄ concentrations of up to 500 μg/l, but a mean value of < 10 μg/l. However, aquiclude and thermal waters from the Carboniferous and Triassic typically contain in excess of 1500 μg/l. Such high concentrations have so far only been found at redox (Eh) potentials below 0 mV, but in general CH₄ concentration and Eh value are poorly correlated. This suggests a lack of thermodynamic equilibrium, which is confirmed by comparing pe values calculated from the redox couple C(4)/C(− 4) with those derived from Eh. Genesis of CH₄ appears to occur on two timescales: a rapid if low rate of production from labile carbon in anaerobic microsites in the soil, and a much longer, millennium scale of production from more refractory carbon. Methane is rarely measured in groundwater; there is no single ionic determinand which acts universally as a proxy, but a combination of high HCO₃ and low SO₄ concentrations, or the reverse, is an indication that high amounts of CH₄ may be present.     

The petroleum generation potential and effective oil window of humic coals related to coal composition and age

A worldwide data set of more than 500 humic coals from the major coal-forming geological periods has been used to analyse the evolution in the remaining (Hydrogen Index, HI) and total (Quality Index, QI) generation potentials with increasing thermal maturity and the ‘effective oil window’ (‘oil expulsion window’). All samples describe HI and QI bands that are broad at low maturities and that gradually narrow with increasing maturity. The oil generation potential is completely exhausted at a vitrinite reflectance of 2.0–2.2%R_o or T_max of 500–510 °C. The initial large variation in the generation potential is related to the original depositional conditions, particularly the degree of marine influence and the formation of hydrogen-enriched vitrinite, as suggested by increased sulphur and hydrogen contents. During initial thermal maturation the HI increases to a maximum value, HI_max. Similarly, QI increases to a maximum value, QI_max. This increase in HI and QI is related to the formation of an additional generation potential in the coal structure. The decline in QI with further maturation is indicating onset of initial oil expulsion, which precedes efficient expulsion. Liquid petroleum generation from humic coals is thus a complex, three-phase process: (i) onset of petroleum generation, (ii) petroleum build-up in the coal, and (iii) initial oil expulsion followed by efficient oil expulsion (corresponding to the effective oil window). Efficient oil expulsion is indicated by a decline in the Bitumen Index (BI) when plotted against vitrinite reflectance or T_max. This means that in humic coals the vitrinite reflectance or T_max values at which onset of petroleum generation occurs cannot be used to establish the start of the effective oil window. The start of the effective oil window occurs within the vitrinite reflectance range 0.85–1.05%R_o or T_max range 440–455 °C and the oil window extends to 1.5–2.0%R_o or 470–510 °C. For general use, an effective oil window is proposed to occur from 0.85 to 1.7%R_o or from 440 to 490 °C. Specific ranges for HI_max and the effective oil window can be defined for Cenozoic, Jurassic, Permian, and Carboniferous coals. Cenozoic coals reach the highest HI_max values (220–370 mg HC/g TOC), and for the most oil-prone Cenozoic coals the effective oil window may possibly range from 0.65 to 2.0%R_o or 430 to 510 °C. In contrast, the most oil-prone Jurassic, Permian and Carboniferous coals reach the expulsion threshold at a vitrinite reflectance of 0.85–0.9%R_o or T_max of 440–445 °C.     

Hydrology and hydrogeology of Sakaryabaşı Karstic springs, Çifteler, Turkey

The Sakarya River is one of the largest rivers in Turkey and is fed mainly from Sakaryabaşı springs. The Sakaryabaşı springs are located in the Central Anatolia and issue from confined/semi-confined karst having a thermal component and therefore, having quite different hydrogeological characteristics as compared to the Taurus Karst region, a typical example of the Mediterranean type of karst. The karstic carbonate rocks that form the groundwater reservoir are overlain by a thick semi-pervious overburden of mainly clastics of Neogene age. Tectonics is the major factor controlling the occurrence of the karst springs in the area where topography is rather flat. This study aimed at explaining the occurrence and movement of the karst groundwater within the system by use of hydrogeological, chemical, and isotopic tools. Isotopic composition of the waters revealed that all waters in the region are of meteoric origin and the thermal component is due to deep circulation. The catchment area of the hydrogeological system extends to the south and groundwater movement is towards the outlets, which are in a depression along a major fault. The movement of the groundwater, based on analysis of remotely sensed images, is controlled mainly by structural elements.