我国东海陆架地区新生代地层的热导率

对东海陆架区的浅表层柱状岩芯样品和多口钻井岩心样品的热导率数据按岩性、深度、年龄和孔隙度进行了统计分析。发现泥岩、粉砂岩和砂岩的热导率有所不同。在3000m以上，泥岩的热导率大于砂岩的热导率；而在3000m以下砂岩的热导率则大于泥岩的热导率。粉砂岩的热导率基本介于泥岩和砂岩之间。岩石的热导率和岩石样品所处的深度密切相关，随着深度的增大热导率数值增大。岩石的年龄影响岩石的热导率。在同等深度的情况下，年龄越老，热导率数值越高，但埋深浅的老地层热导率会小于埋深大的新地层的热导率。孔隙度和含水对岩石样品的热导率有很大的影响，岩石会因孔隙中含水而使热导率有非常大的变化。本文给出了饱和水热导率和干样热导率之差和孔隙度的回归方程。     

盆地沉降史回剥分析的不确定性及参数影响

回剥分析(backstripping)是盆地沉降史分析的核心方法,应用极为广泛;但对其分析结果的不确定性及参数对分析结果的影响的关注甚少。以珠江口盆地白云凹陷地区为例,探讨了原始数据和选用参数(包括无钻井揭示的基底埋深和界面年龄、地层划分、孔隙度随深度变化曲线、沉积岩性、古水深和全球海平面变化等)对回剥分析结果的影响。理论分析和灵敏度试验表明,无钻井揭示的基底埋深的误差影响回剥分析的所有结果;界面年龄的误差仅影响对沉积速率和构造沉降速率的估计;岩性的影响反映在选取密度和孔隙度随深度变化的曲线参数之中,孔隙度在不同地区可能有较大差异;而古水深是回剥分析参数中不确定性最大的因素,古水深的误差不影响去压实厚度和沉积速率,但却100%成为构造沉降量的误差。由于陆坡区古水深和岩性随位置的变化较大,这两种参数对陆坡区回剥分析结果的影响尤为显著,需要采用随位置而变的参数,特别需要综合利用各种地质地球物理资料估计各地层沉积时的古水深变化。数据的不确定性及参数选取的不当有可能导致谬误的结果,因此发表回剥分析结果时应该说明主要参数的选取依据,而对于文献中发表的回剥分析结果则必须在考察其数据和参数的不确定性后才能考虑采用与否。     

钻前压力预测的关键问题及解决方法

地层压力研究是一个重大的地质问题。地层压力预测,不但有利于油气地质研究,而且对钻井安全的保障起到至关重要的作用。地层超压可导致地震波速度下降。因此,目前地层压力主要的预测方法是地震速度预测法。压力预测的关键问题是地层层速度的求取问题。只有获得了高精度、高分辨的速度场,才能得到较准确的压力场。实践中,我们进行了①地震资料精细处理,尽可能把多次波去干净,提高信噪比和分辨率,加密速度谱解释;②地震层析成像;③测井约束地震波阻抗反演;④叠前深度偏移,以此来获得相对较高精度的速度场,进而得到较可靠的压力场。     

东海深部地层时深转换关系的分段优化拟合

在将钻井垂直地震剖面(VSP)数据的时深拟合公式应用于深部地层的时深转换时,拟合深度与计算的层速度常常不够准确。本文首先利用多项式和幂函数给出了东海陆架盆地中部某凹陷41口钻井VSP数据的时深拟合公式,并用双程旅行时(TWT)最深达8 s的三维地震速度体数据与多道地震剖面对拟合公式在深部地层的适用性进行分析。在TWT为8 s时,速度体数据表明41口钻井位置的平均深度为18 140 m,平均层速度为6 208 m/s,二次多项式的平均拟合深度较之偏高9.2%,计算的层速度偏高36.2%,幂函数则分别偏低28.9%与35.6%,拟合效果都不理想。对此,本文采用通过识别VSP数据的增速拐点并对增速拐点前的VSP数据进行二次多项式拟合,对增速拐点后的VSP数据进行幂函数拟合的分段拟合模型,将TWT为8 s时的平均拟合深度和层速度的误差降到3.3%与4.7%。地震剖面显示研究区莫霍面深度约为TWT=11 s,分段拟合模型在TWT=11 s的平均拟合深度为27 516 m,层速度为7 334 m/s,更接近前人研究成果,表明该模型能显著提高深部地层时深转换的精度。     

我国近海沉积层地震速度特征

我国近海纵向上发育了新生界、中生界碎屑岩和古生界沉积地层。在分析整理收集到的地层速度资料的基础上,分析了地层速度的变化规律:沉积层地震速度随地层的埋深增加而增加,新地层速度低、老地层速度高;欠压实地层的砂岩速度与泥岩速度基本相当或低于泥岩速度,正常地层的砂岩速度大于泥岩速度;砂岩储层的速度随孔隙度的增加而降低,流体成分的变化对速度的影响不大。     

地震初至波速度层析成像技术在南黄海盆地崂山隆起的应用

崂山隆起位于南黄海盆地的中部,新生代地层沉积薄,其底部存在高速屏蔽层,加上中—古生代地层经历了多期构造运动,导致中—古生界地震有效反射信号弱、成像效果较差,地震处理中采用常规速度谱拾取不能准确获得高速屏蔽层下的地层速度,给叠前时间偏移和叠前深度偏移的速度建模工作带来很大困难。近几年,青岛海洋地质研究所在南黄海崂山隆起采集了大容量震源长电缆地震数据,获得了来自中—古生界的初至波信息。采用初至波层析成像方法来揭示高速屏蔽层下中—古生界速度变化信息,主要通过拾取初至波时间,建立初始速度模型,经过不断迭代反演得到最终速度模型。结果表明,高速屏蔽层下地层速度横向变化剧烈,存在速度为3 500~4 000m/s的低速层,预测为碎屑岩;速度为5 100~5 500m/s的高速层,预测为碳酸盐岩地层。     

基于地震速度构建的低频响应在波阻抗反演中的应用

以V工区北部为例,应用井数据、速度数据和地震属性共同恢复低频响应数据,同时使用层速度、层位信息（层的深度和厚度）以及反射振幅的信息进行反演,结果显示可以改善预测纵波阻抗的结果,同时与通常情况下的孔隙度预测作了对比,结果表明孔隙度预测的可信度得到了一定程度的改善。     

元素俘获测井在绥中36-1油田的应用

由于并眼条件、钻井液等因素的影响,利用常规测井资料处理得到的岩性剖面会存在一定偏差,造成储层孔隙度计算不精确甚至流体性质判别失误.元素俘获测井（ECS）是斯伦贝谢公司研发的新一代测量地层元素的测井技术,利用其资料确定黏土含量及类型从而获得精确的岩性剖面,结合常规测井数据可以准确计算地层孔隙度,提高测井解释的符合率.介绍了ECS测井原理及其仪器参数,通过在绥中36-1油田的应用,阐述ECS的测井优势,对该技术的推广应用有着重要意义.     

BZ13-1油田井壁稳定性研究及应用

位于渤海中部海域的BZ13-1油田在前期钻井中存在溢流、井漏、阻卡等较多复杂问题,制约了钻井速度。井壁稳定的力学分析方法主要利用钻井资料、测井资料、录井资料等,分析地层压力、地应力、地层强度参数的分布规律,结合岩体强度准则计算坍塌压力与破裂压力,得出钻井安全密度窗口。通过对BZ13-1油田井壁稳定性进行分析,得出了高压层、易漏失层、易坍塌层位置,并据此对开发井进行井身结构设计,分析结果在开发井钻井中取得了良好的应用效果,有效减少了钻井复杂问题。     

南黄海新近纪以来地层沉积特征研究的地震技术方法

地震技术方法是研究海底之下地层沉积特征的主要手段。针对地震资料特点和研究需求,开展了新近系以来的沉积特征的地震方法研究,利用资料净化、多次波压制和高分辨率岩性处理等技术方法,提高了地震资料的信噪比和分辨率;采用基于多道地震叠加速度资料基础的速度分析和时间—深度转换方法,保证了沉积地层埋藏深度的计算精度;以海洋地质学、地震地层学的方法为指导,预测地层岩相并评判了沉积环境。CSDP-1孔的钻探结果证明研究方法的有效性。     

黄海、渤海底层盐度预报方法的研究

根据二维流体动力学方程和深度平均盐度扩散方程在河口径流量以及蒸发和降水之差为已知情况下构成的闭合方程组，预报出深度平均盐度，然后利用底层盐度与深度平均盐度、水深和时间（月）之间的经验关系，给出底层盐度的二维预报。为了检验试报结果的可靠性，文中将黄渤海底层盐度的试报结果（１９７年７月１１日，时效为３ｄ）与标准断面观测资料（７月１１日观测，１２４．５°Ｅ以西，共１０４站）作一粗略比较。比较表明，试报结果与实测值的相关系数为０．９６，均方误差为σ＝０．２６，绝对误差小于０．２和０．３的站数分别占总站数的６３．５×１０－２和７７．０×１０－２，而总均绝差为０．１９。由此可见，试报的效果是令人满意的。     

黄渤海底层盐度预报方法的研究

根据二维流体动力学方程和深度平均盐度扩散方程在河口径流量以及蒸发和降水之差为已知情况下构成的闭合方程组,预报出深度平均盐度,然后利用底层盐度与深度平均盐度、水深和时间(月)之间的经验关系,给出底层盐度的二维预报。为了检验试报结果的可靠性,文中将黄渤海底层盐度的试报结果(1979年7月11日,时效为3d)与标准断面观测资料(7月4—14日观测,124.5°E以西,共104站)作一粗略比较。比较表明,试报结果与实测值的相关系数为0.96,均方误差为α=0.26,绝对误差小于0.2和0.3的站数分别占总站数的63.5％和77.0％,而总均绝差为0.19。由此可见,试报的效果是令人满意的。     

2011—2012年冬季山东半岛北部沿海冰情趋势预测

较详细地绘出了该海域内50年来海水温度的变化周期及分布特征,并利用热平衡原理和数理统计方法,预测2011—2012年度海冰发展趋势。经多年检验该方法较为稳定、有效,能够较准确的预报局部海域冰情。     

基于机器学习的海洋浮标寿命及轨迹预测

Argo计划(Array or Real-time Geostrophic Oceanography)为海洋和大气研究提供了宝贵的资料,在短期天气预报和长期气候预测中起到了重要作用.为保证Argo观测阵列的正常运转,需要时刻关注浮标的运行状态,以保证研究区域内维持一定数量和密度的浮标.然而Argo浮标投放费用高昂,投放...     

A new nudging scheme for the current operational climate prediction system of the National Marine Environmental Forecasting Center of China

A new nudging scheme is proposed for the operational prediction system of the National Marine Environmental Forecasting Center(NMEFC) of China, mainly aimed at improving El Ni?o–Southern Oscillation(ENSO) and Indian Ocean Dipole(IOD) predictions. Compared with the origin nudging scheme of NMEFC, the new scheme adds a nudge assimilation for wind components, and increases the nudging weight at the subsurface. Increasing the nudging weight at the subsurface directly improved the simulation performa...     

Exploring conventional tidal prediction schemes for improved coastal numerical forecast modeling

This study provides a practical guide to the use of classical tidal prediction algorithms in coastal numerical forecasting models such as tide and tide-storm-surge models. Understanding tidal prediction parameter formulas and their limitations is key to successfully modifying and upgrading tidal prediction modules in order to increase the accuracy of perpetual interannual simulations and, in particular, storm-surge modeling studies for tide-dominated coastal environments. The algorithms for the fundamental prediction parameters, the five astronomical variables, used in tidal prediction are collated and tested. Comparisons between their estimation using different parameterizations shows that these methods yield essentially the same results for the period 1900–2099, revealing all are applicable for tidal forecasting simulation. Through experiments using a numerical model and a harmonic prediction program, the effects of nodal modulation correction and its update period on prediction accuracy and sensitivity are examined and discussed using a case study of the tidally-dominated coastal regime off the west coast of Korea. Results indicate that this correction needs updating within <30 days for accurate perpetual interannual tidal and mean sea-level predictions, and storm-surge model predictions requiring centimeter accuracy, for tidally-dominated coastal regimes. Otherwise, unacceptable systematic errors occur.     

A Dynamical Statistical Model for Prediction of a Tropical Cyclone

A dynamical statistical method is applied for operational forecasting of the Bay of Bengal tropical cyclone “Nargis” of April–May 2008. The method consists of three forecast components, namely (a) analysis of Genesis Potential Parameter (GPP) and maximum potential intensity, (b) track prediction, and (c) 12 hourly intensity prediction for forecasts up to 72 hours. The results of the study showed that GPP could provide necessary predictive signal at early stages of development on the further intensification of the low pressure system into a tropical cyclone. The landfall forecast position errors by different operational numerical models (NWP) showed landfall position errors ranging from 10 km to 150 km and landfall time error ranges from 6 hours early to 6 hours delay. The dynamical statistical model is capable to provide 12 hourly nearly realistic intensity forecasts up to 60 hours of forecast.     

Deterministic non-linear wave prediction using probe data

The accurate prediction of non-linear sea states represents a great challenge, with a number of applications in oceanography, marine engineering, security of people and marine transportation, etc. In this paper, we report on the development of two efficient deterministic prediction models for 2D irregular wave-fields. These models are based on the exploitation of wave elevation time series given by one or more probes and on the use of two different numerical models for the wave-fields simulation. Two effective data assimilation processes are developed to improve the wave-field estimates obtained from the study of one or several probe signals, so that we obtain proper initial conditions for the forecast. The assimilation schemes have been validated on the reconstruction of model-generated observations and accurate predictions of the corresponding synthetic wave-fields evolution have been obtained.     

渤海、黄海强温跃层数值预报模式

文中对前人关于水温垂直结构计算、模拟和预报研究成果进行了评价，并在此基础上建立了考虑海面吸收辐射和透射辐射、地形、风、海流、界面摩擦及其引起的混合作用的强温跃层三维数值预报模式。该模式运行的驱动量仅为风和气温场资料，因而具有较好的实用性；此外，从试报的结果看，效果是令人满意的。     

Obtaining the distribution of quiescent periods directly from the power spectral densities of Sea waves

There is a growing practical interest in the ability to increase the sea states at which marine operations can be safely undertaken by exploiting the quiescent periods that are well known to exist under a wide range of sea conditions. While the actual prediction of quiescent periods at sea for the control of operations is a deterministic process, the long term planning of future maritime tasks that rely on these quiescent periods is a statistical process involving the anticipated quiescence properties of the forecasted sea conditions in the geographical region of interest. It is in principle possible to obtain such data in tabular form either large scale simulation or from field data. However, such simulations are computationally intensive and libraries of appropriate field data are not common. Thus, it is clearly attractive to develop techniques that exploit standard wave spectral models for describing the quiescence statistics directly from such spectra. The present study focuses upon such techniques and is a first step towards the production of a computationally low-cost quiescence prediction tool and compares its efficacy against simulations. Two significant properties emerge for a large class of wave spectral models that encompasses the ubiquitous Neumann and Pierson Moskowitz or Bretschneider forms. Firstly, the auto-correlation function of the wave profile that are required to produce the quiescence property can be obtained analytically in terms of standard special functions. This considerably reduces the computational cost making desktop computer-based planning tools a reality. Secondly, for each class of these parametric spectra, the probability of a given number of consecutive wave heights (normalised to the significant wave heights) less than some critical value is in fact independent of absolute wave height. Thus, for a broad class of practically interesting wave spectra all that is required to obtain the statistical distribution of the quiescent periods is simple rescaling.