地震学定量预报指标的一种提取方法——对比筛选法

鉴于目前地震学综合定量预报指标的缺乏和预报工作的急需,尝试使用“对比筛选法(简称CSM方法)”进行地震学定量预报指标的提取试验。较之以往作法的进展在于:1.同时使用“有震”和“无震”两类样本对比筛选;2.对不同地区的地震学参数进行了归一化处理。这样做的显著优点是:1.可以较有效地提取“有震异常”和“正常变化”指标;2.提取的异常和预报指标具有定量化和普适性特点。 试验研究使用大华北地震区资料,研究对象取中强地震。经内符和外推检验,证明该方法提取的异常和预报指标有效性和实用性较高。     

涠西南地区岩石特性及钻井液技术研究

北部湾盆地涠西南油田群是南海西部重要的原油产区，同时油田群紧邻众多国家级自然保护区，属于环境敏感区域。针对北部湾盆地涠西南地区环保要求，以及涠洲组和流沙港组钻井过程经常出现井壁失稳导致的憋卡、起下钻阻卡等问题，开展了涠西南地区地层泥页岩特性及环保钻井液技术研究。通过地层岩石黏土矿物分析、孔喉结构分析以及理化性能评价，明确了涠西南地区泥页岩井壁失稳的机理；提出以类油基的水溶性复合基基液为核心，构建了一套具有油基钻井液工程特性和水基钻井液环保特性的新型环保防塌钻井液技术，并进行了相关的现场应用。现场应用显示：应用井与邻井相比，12-1/4″井段阻卡划眼时间减少，井径扩大率大幅度降低，并且在128 h的长时间浸泡过程中没有复杂情况产生，有效地解决了涠洲组、流沙港组易失稳地层的井壁稳定问题；同时，钻井液环保性能达到一级海域环保要求，可以替代目前应用的油基钻井液体系，解决了海上使用油基钻井液存在配制成本高、含油钻屑需全回收及环境危害隐患大等技术难题。该研究对于涠西南油田环保、井壁失稳和钻井液技术发展具有较高的理论价值和借鉴意义。     

重视和加强岩矿物性的测量研究

本文从物探科学技术的进步,勘查任务的发展变化、物探方法应用范畴的扩大和物性勘探等几个方面,论述了岩石和矿物物理性质测量、研究的重要性,指出：物性工作不可能毕其功于一役,并提出了五点建议：１．深入研究各类矿藏及其围岩（直至地面）物性的空间变化规律,为选择、研究合适的物探方法,提高物探效果,进一步探讨“直接”找矿问题,提供依据;２．这项工作可专门进行,但最好尽可能利用为其他目的而设计的钻井进行;３．物     

Sedimentary Features of Shallow Ancient River Channels on the Northern Shelf of the South China Sea

Quaternary buried ancient river channels are widespread in the shallow-level sediments of the northern shelf of the South China Sea. The sedimentary sequence mainly of fluvial deposits comprise an important component part of the low-stand system tract and transgressive system tract in the study region. The plannar variation and spatial association of the sedimentary features such as incised valley fillings, deltaic foreset wedges and block slides of shelf-marginal fans reflect the palaeogeographic environment during the fall of the regional sea level in the northern part of the South China Sea. Based on the high-resolution seismic reflection data and gelogical data from boreholes, the present paper makes an integrated interpretation of the Quaternary ancient river channels in the shallow sediments of the study area, studies the sedimentary features of the ancient channels such as their spatial distribution, seismic facies reflection indicators, sedimentary facies and sand -body types, and discusses thei     

论Eppley PIR精密红外辐射仪的测量精度

本文依据红外辐射表(PIR)的结构、性能和工作原理讨论了测量精度及有关影响因素,比较了粗测和精测两种方法的特点,在此基础上提出了各测量方法的适用范围和精度范围以及提高测量精度的措施,同时也给出了一些特定场合下的测量实例及提高测量精度的具体方法。分析表明:精测方法具有很好的测量精度以及很强的环境适应性。粗测在限定的温度范围内具有测量简单、换算方便、易于实现自动化等优点,精度尚能满足一般要求,但在限定的温度范围以外,测量精度急剧恶化。在影响测量精度的各因素中以温度响应中表体热辐射测量的影响最大,在粗测方法中表内电池的性能与测量精度关系重大。强烈日射对测量精度有一定影响,经订正后可基本消除。     

Oil-generation kinetics for organic facies with Type-II and -IIS kerogen in the Menilite Shales of the Polish Carpathians

The Menilite Shales (Oligocene) of the Polish Carpathians are the source of low-sulfur oils in the thrust belt and some high-sulfur oils in the Carpathian Foredeep. These oil occurrences indicate that the high-sulfur oils in the Foredeep were generated and expelled before major thrusting and the low-sulfur oils in the thrust belt were generated and expelled during or after major thrusting. Two distinct organic facies have been observed in the Menilite Shales. One organic facies has a high clastic sediment input and contains Type-II kerogen. The other organic facies has a lower clastic sediment input and contains Type-IIS kerogen. Representative samples of both organic facies were used to determine kinetic parameters for immiscible oil generation by isothermal hydrous pyrolysis and S₂ generation by non-isothermal open-system pyrolysis. The derived kinetic parameters showed that timing of S₂ generation was not as different between the Type-IIS and -II kerogen based on open-system pyrolysis as compared with immiscible oil generation based on hydrous pyrolysis. Applying these kinetic parameters to a burial history in the Skole unit showed that some expelled oil would have been generated from the organic facies with Type-IIS kerogen before major thrusting with the hydrous-pyrolysis kinetic parameters but not with the open-system pyrolysis kinetic parameters. The inability of open-system pyrolysis to determine earlier petroleum generation from Type-IIS kerogen is attributed to the large polar-rich bitumen component in S₂ generation, rapid loss of sulfur free-radical initiators in the open system, and diminished radical selectivity and rate constant differences at higher temperatures. Hydrous-pyrolysis kinetic parameters are determined in the presence of water at lower temperatures in a closed system, which allows differentiation of bitumen and oil generation, interaction of free-radical initiators, greater radical selectivity, and more distinguishable rate constants as would occur during natural maturation. Kinetic parameters derived from hydrous pyrolysis show good correlations with one another (compensation effect) and kerogen organic-sulfur contents. These correlations allow for indirect determination of hydrous-pyrolysis kinetic parameters on the basis of the organic-sulfur mole fraction of an immature Type-II or -IIS kerogen.     

双坡面临空岩质边坡滑动破坏模式下的稳定性分析

多数岩质边坡稳定性分析已基本解决了常走向单坡面临空的边坡平面滑动问题。然而,在路堑边坡工程和自然边坡中有很多边坡坡面并不是平面,它包含多个坡面。多坡面边坡包含两个或多个不同走向的坡面。多坡面边坡几何特征不同于单坡面边坡,所以滑动条件也不一样。在赤平投影图上,多坡面的滑动包络线是组成边坡的每个坡面单独投影包络线的组合。为了探讨方便,只讨论了双坡面临空岩质边坡的滑动破坏模式,并将其分为双坡面临空下的平面破坏和楔形体破坏。在赤平投影图上,双坡面滑动区域定义为双坡面边坡滑动包络图中两侧坡面的真倾线之间的面积。如果有一两个节理面真倾向线落在滑动区内,滑动破坏才可能发生。     

T -distributed Random Fields: A Parametric Model for Heavy-tailedWell-log Data1

Histograms of observations from spatial phenomena are often found to be more heavy-tailed than Gaussian distributions, which makes the Gaussian random field model unsuited. A T-distributed random field model with heavy-tailed marginal probability density functions is defined. The model is a generalization of the familiar Student-T distribution, and it may be given a Bayesian interpretation. The increased variability appears cross-realizations, contrary to in-realizations, since all realizations are Gaussian-like with varying variance between realizations. The T-distributed random field model is analytically tractable and the conditional model is developed, which provides algorithms for conditional simulation and prediction, so-called T-kriging. The model compares favourably with most previously defined random field models. The Gaussian random field model appears as a special, limiting case of the T-distributed random field model. The model is particularly useful whenever multiple, sparsely sampled realizations of the random field are available, and is clearly favourable to the Gaussian model in this case. The properties of the T-distributed random field model is demonstrated on well log observations from the Gullfaks field in the North Sea. The predictions correspond to traditional kriging predictions, while the associated prediction variances are more representative, as they are layer specific and include uncertainty caused by using variance estimates.