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51.
以地质统计学为基础的三维地质建模技术已成为当今储层精细描述中的一项关键技术,但该项技术存在着一个最大的限制就是对硬数据的密度要求十分苛刻,因而多用于井网密度大的已开发区的储层精细描述。而在勘探区块,多采用地震属性资料作为软约束,来弥补资料不足的缺陷。本文以我国海上某油田为例,探讨了应用地震反演资料约束三维储层建模的几种方法,并提出"多条件、多级约束"的建模策略。研究表明,有效地应用包括地震信息在内的多学科信息进行岩相随机建模,能有效地弥补井间信息不足的缺陷,降低地质模型的不确定性,所建立的模型能很好地综合井资料的纵向高精度和地震资料的横向高精度信息,可以成功地应用三维随机建模技术解决勘探开发阶段的储层精细描述问题。  相似文献   
52.
53.
The coastal region adjacent to Tomales Bay, California is dominated by wind-driven upwelling during spring and summer and the cold, upwelled water is moved towards Tomales Bay, entering the estuary with the flood tide. If the tidal excursion is ≥6 km and the cold water subducts beneath the warmer, less dense estuarine water, a temperature controlled density current may form and intrude towards the head of the estuary as a thermally stratified bottom layer. The numerical modelling was aimed at determining the capability of the Delft3D-FLOW model to reproduce the cold ocean water intrusion events, the response (development and progression) of these intrusions to differing physical scenarios and the comparative importance of the parameters to the intrusions. The numerical model successfully reproduced the density intrusions and showed that the persistence and break down of the density intrusions were affected by a number of physical parameters, to varying degrees. The sensitivity analysis showed that density intrusion formation is controlled by tidal conditions and ocean water temperature. The strength and persistence of the developed density intrusions are influenced by wind, insolation and estuary depth. Fresh water inflow at the head of the estuary had no impact on the density intrusions. Three-dimensional numerical modelling is thus a valuable tool in understanding the estuary and its functioning.  相似文献   
54.
Two controlled flow events were generated by releasing water from a reservoir into the Olewiger Bach, located near Trier, Germany. This controlled release of near bank‐full flows allowed an investigation of the fine sediment (<63 µm) mobilized from channel storage. Both a winter (November) and a summer (June) release event were generated, each having very different antecedent flow conditions. The characteristics of the release hydrographs and the associated sediment transport indicated a reverse hysteresis with more mass, but smaller grain sizes, moving on the falling limb. Fine sediment stored to a depth of 10 cm in the gravels decreased following the release events, indicating the dynamic nature and importance of channel‐stored sediments as source materials during high flow events. Sediment traps, filled with clean natural gravel, were buried in riffles before the release of the reservoir water and the total mass of fine sediment collected by the traps was measured following the events. Twice the mass of fine sediment was retained by the gravel traps compared with the natural gravels, which may be due to their altered porosity. Although the amount of fine sediment collected by the traps was not significantly related to measures of gravel structure, it was found to be significantly correlated to measures of local flow velocity and Froude number. A portion of the traps were fitted with lids to restrict surface exchange of water and sediment. These collected the highest amounts of event‐mobilized sediments, indicating that inter‐gravel lateral flows, not just surface infiltration of sediments, are important in replenishing and redistributing the channel‐stored fines. These findings regarding the magnitude and direction of fine sediment movement in gravel beds are significant in both a geomorphic and a biological context. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
55.
关于渤海湾盆地渤中19- 6凝析气田凝析油成熟度存在成熟与高成熟两种截然不同观点,尚未达到统一定论。本文综合利用轻烃、饱和烃和芳烃成熟度参数对凝析油成熟度进行了综合判定,并深入分析了凝析油和天然气的成因关系及凝析气藏形成机制。结果表明:异庚烷值与庚烷值、Ts/(Ts+Tm)与C29Ts/(C29Ts+C29H)、甲基单金刚烷指数与甲基双金刚烷指数、甲基菲指数、二苯并噻吩类成熟度参数和TNR2显示渤中19- 6凝析气田凝析油处于成熟阶段。结合天然气成熟度和储层流体包裹体特征,可知渤中19- 6凝析气田的原油成藏期早于天然气,随着晚期大量天然气的充注,油气会发生相控混溶作用形成含液态烃的气流体,当温度和压力达到混溶后烃类体系的露点以上,则形成凝析气藏。  相似文献   
56.
本文结合福州电厂粉煤灰室内试验结果分析,探讨粉煤灰扰动样现场取样及试验控制干密度的等问题,该电厂粉煤灰的沉积规律与其它电厂有所不同,灰料颗粒组细分布和距排灰口远近基本无关,取样也不能按以往经验进行。  相似文献   
57.
本文介绍所研制的由MCS-51单片机控制的步进电机定频脉宽调制可变细分驱动系统。该系统采用单电压驱动。配有软件。在不改变硬件电路的前提下.通过键盘操作,可以改变细分数。系统采用数字式定频脉宽调制技术,直接对细分电流进行反馈控制。最后提出了用实验确定均匀细分电流状态字的新方法,并验证了其可行性。  相似文献   
58.
A foreland basin succession has been identified in the Frasnian of the Central Pyrenees. This succession comprises a carbonate-dominated transgressive system which recorded the cratonward migration of the foreland basin subsidence, and siliciclastic depocenters which recorded the progression of the thrust-fold deformation. The foreland basin system has always been maintained in deep-marine environments, i.e., at an underfilled depositional state. It was associated with a thrust wedge which descended toward a deep-marine hinterland, i.e., with a type of orogenic wedge usually related to subduction zones. The Frasnian foreland basin system differs from the one known in the Carboniferous which evolved to overfilled depositional state and was associated with a thrust wedge rising toward a mountainous hinterland. Consequently, the Hercynian orogeny in the Pyrenees seems to result first, from a Frasnian thrusting controlled by a subduction zone located north of the Pyrenees, and second, from a Carboniferous thrusting controlled by the surrection of a frontal thrust belt in the Pyrenees. The association of underfilled foreland basin systems and hinterland-dipping thrust wedges, as exemplified in the Frasnian of the Pyrenees, can be interpreted as illustrative of the initial stages of thrust-wedge growth in deep-marine settings.  相似文献   
59.
本文提出了月球摄影测量数据处理系统的设计原则,探讨了月球摄影测量数据处理系统的组成和研究的内容,分析了在月球探测摄影测量数据处理中,首先应该解决的关键技术问题。结论:对月球探测摄影测量数据处理系统的研究,可以保障月球探测卫星工程测绘月球表面三维影像图及地形图任务的完成,同时,也可以为后续的月球探测计划提供摄影测量的基础理论、技术、方法和实践经验。  相似文献   
60.
The safety and stability of concrete and masonry dams is a great concern when blasting has to be conducted close to these dams in order to construct small hydro-electric projects. There is a danger of ground vibration amplification to those residential-type buildings that are built close to these dams.

Responses of three concrete and masonry dams were measured directly by conducting a number of blasts and by monitoring vibration in the ground as well as on the dams. The amplitudes and frequencies of the motions were analysed and vibration attenuation relations were derived. These relations were used to compare the vibration levels on the dams with those in the ground.

Because of close-in construction blasts that produced high frequency ground vibrations, there was no amplification of the ground vibrations by these dams. The measured amplitudes of ground vibration were comparable to those of the dams.  相似文献   
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