Reservoir potential of Late Cretaceous terrestrial to shallow marine sandstones,Taranaki Basin,New Zealand   总被引：2，自引：0，他引：2  

K.E. Higgs  M.J. Arnot  G.H. Browne  E.M. Kennedy 《Marine and Petroleum Geology》2010

Late Cretaceous coals and coaly source rocks are the main source of hydrocarbons in the Taranaki Basin, yet to date there have not been any hydrocarbon discoveries within Cretaceous strata, and sandstone distribution and reservoir quality for this interval have been poorly understood. The Late Cretaceous sediments were deposited in several sub-basins across Taranaki, with their distribution largely determined by sediment supply, subsidence, and sea level change. In this study, we describe potential reservoir facies in well penetrations of Cretaceous strata in Taranaki, as well as from outcrop in northwest Nelson, on the southern edge of the basin.  相似文献   

pT-effects of Pleistocene glacial periods on permafrost,gas hydrate stability zones and reservoir of the Mittelplate oil field,northern Germany     

S. Grassmann  B. Cramer  G. Delisle  T. Hantschel  J. Messner  J. Winsemann 《Marine and Petroleum Geology》2010

During the past two million years low surface temperatures as well as episodically advancing ice sheets from Scandinavia acted on the subsurface pT-regime of northern Germany. Their likely effects on the petroleum system of Schleswig-Holstein were investigated. For the entire Quaternary mean annual ground temperature (MAGT) was reconstructed at a resolution of 1000 years by calibrating oxygen isotope records from ODP-site 659 to the climate of northern Germany of the past 120 kyr. The resulting MAGT trend served as input to an ice sheet model and a permafrost model along a 2D section crossing the petroleum bearing south-western part of Schleswig-Holstein. Here advances and retreats of the Scandinavian ice sheet during Saalian and Elsterian glaciation Stages were reconstructed. Maximum ice thicknesses of up to 1700 m and up to 20 periods of regional permafrost in northern Germany were reconstructed for the past 1.25 million years. Based on a basal heat flow of 50 mW/m² permafrost thicknesses exceeded 100 m during most of these periods, temporarily extending down to depths of more than 300 m. Favourable surface temperatures and long durations of cold periods provided favourable conditions for onshore gas hydrate stability zones at Mittelplate. Implementing these glacial dynamics into 2D basin modelling (PetroMod, IES, Aachen, Germany) of the Mittelplate oil field reveals five phases of gas hydrate stability at depths down to 750 m. The latest of these events occurred during the Weichselian about 20 kyr ago. The effect of the ice sheets on pore pressure in the subsurface strongly depends on the hydraulic boundary conditions at the ice base (e.g. frozen vs. temperate ice sheet base). Excess pore pressure in the reservoir of more than 10 MPa during ice overriding is possible and probable. The calculated temperature effect of the Pleistocene cooling on the Mittelplate reservoir is in the range of 3–7 °C. Even today temperature in the reservoir is still lowered by about 4 °C in comparison to pre-Pleistocene times. Despite the fact that a significant influence of glacial effects on petroleum generation can be ruled out at Mittelplate, we state that pT-effects in reservoirs related to glacial processes in formerly glaciated areas have been underestimated in the past.  相似文献   

Reprint of: Diagenetic controls on evolution of porosity and permeability in lower Tertiary Wilcox sandstones from shallow to ultradeep (200–6700 m) burial,Gulf of Mexico Basin,U.S.A.     

Shirley P. Dutton  Robert G. Loucks 《Marine and Petroleum Geology》2010

Reservoir quality is a critical risk factor in deep to ultradeep reservoirs at depths >4.5 km. Analysis of Paleogene Wilcox sandstones on the upper Texas Gulf Coast provides insight into the evolution of reservoir quality during shallow to ultradeep burial diagenesis. Reduction of porosity and permeability with burial in Wilcox sandstones was evaluated using subsurface samples from 200 to 6700 m, at temperatures of 25–230 °C. Diagenesis and petrophysical properties were interpreted from petrographic data and core analyses. Wilcox sandstones are mostly lithic arkoses and feldspathic litharenites having an average composition of Q₅₉F₂₂R₁₉. Provenance did not change significantly during Wilcox deposition in this area, nor does average sandstone composition vary among lower, middle, and upper Wilcox sandstones. However, composition does vary with sequence-stratigraphic position; lowstand slope-fan deposits contain more rock fragments than do deposits from highstand or transgressive systems tracts. Given observations from this onshore dataset, Wilcox sandstones deposited in deepwater environments in the Gulf of Mexico are likely to contain more rock fragments than their linked highstand equivalents.  相似文献   

Siltation analysis in the Neyyar reservoir and forest degradation in its catchment: a study from Kerala state, India     

D. S. Suresh Babu  V. Nandakumar  B. John  B. K. Jayaprasad  S. V. Pramod 《Environmental Geology》2000,39(3-4):390-397

 Impact of catchment erosion and the resultant reservoir siltation from a tropical environment is reported here to discuss the effect of a reservoir in the natural degradation of an evergreen-forested segment. While an area of 8.01 km² has been affected by direct inundation at the full reservoir level, another 2.6 km² area once under thick forest cover, had also lost its identity over the last 38 years by indirect degradation. This zone mainly falls in the confluence of tributaries, namely Neyyar and Mullayar, with the reservoir. The capacity of the reservoir was found to be reduced by 28.8 Mm³ during this period and the annual average loss is calculated as 0.75 Mm³ (0.71%), indicating the intensity of erosion from the catchment zone. In case the proposed upper dam in the reservoir comes into existence, an additional area of 2.4 km² from the virgin forest would be submerged and more area would face degradation around the inundated zone. Received: 29 July 1998 · Accepted: 16 November 1998  相似文献   

Effects of different operational modes on the flood‐induced turbidity current of a canyon‐shaped reservoir: case study on Liuxihe Reservoir,South China     

Sheng Wang  Xin Qian  Bo‐Ping Han  Lian‐Cong Luo  Rui Ye  Wen Xiong 《水文研究》2013,27(26):4004-4016

Suspended matter is an important indicator of water quality in freshwater systems. The flood‐induced turbidity current plays a dominant role in the seasonal dynamic of suspended matter in the Liuxihe Reservoir (23°45′50″N; 113°46′52″E), a large, stratified reservoir at the Tropic of Cancer in southern China. Field measurements show that loading and distribution of suspended matter in the reservoir differ in typical wet, dry and medium years, as a result of different discharge volumes and water level variation patterns. Using historical data and the practical demand for water supply and flood control, we generalized two feasible reservoir operational modes: flood impounding mode (drawing down the reservoir to a low level before flood events to impound inflow during the flooding season) and moderate level change mode (drawing down the reservoir to a moderate level before flood events, then keeping the level within the flood control level during runoff events). To examine the effects of different operational modes and outlet depths on the reservoir's flood‐induced turbidity current, a numerical simulation model was applied in three types of hydrological conditions. The results show that the mode with moderate drawdown and recharge processes can decrease loading of suspended matter in spring and promote turbidity current release during flood events, and upper withdrawal can improve the effects of turbid water release. We suggest that more attention should be focused on water quality management in the reservoir operation stage, severe artificial water level fluctuation being avoided and selective withdrawal becoming an optional management measure. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Changjiang River sediment delivering into the sea in response to water storage of Sanxia Reservoir in 2003   总被引：3，自引：0，他引：3  

CHU Zhongxin  ZHAI Shikui  CHEN Xiufa 《海洋学报(英文版)》2006,25(2):71-79

1 IntroductionHuman activitieshavebeen stronglyaffecting theworld river sedimentsupply to the oceans since the19thor20thcentury(StanleyandW arne,1993;Fanos,1995;Sm ithandW inkley,1996;Stanley,1996;Yang,Shi,etal.,2004;Yang,Zhao,etal.,2002).Thesedi-m enttra…  相似文献   

Standard facies models to incorporate all heterogeneity levels in a reservoir model     

D. Mikes  C.R. Geel 《Marine and Petroleum Geology》2006,23(9-10):943-959

The construction of reservoir models is frustrated by the fact that core and well cover only a fraction of the reservoir volume and it is therefore difficult to determine features like facies shape, -size, and -distribution, inter- and intra-facies boundaries and lateral trends from them. These features are, however, critical to fluid flow and they should necessarily be incorporated in the reservoir model and we therefore propose to systematically describe geometry and distribution of facies. To this end we make use of “standard facies models” that a priori contain all elements and boundaries of facies for a number of typical depositional environments.  相似文献   

山东省大中型水库水化学性状研究──几种主要水化因子的变化及其在评价水库鱼产力中的作用     

刘新  李德尚  李静 《中国海洋大学学报(自然科学版)》1994,(4)

本文通过对山东省３８座代表性大、中型水库总氮（ＴＮ）、总磷（ＴＰ）、化学耗氧量、硬度及电导率（λ）五种主要水化因子连续两年（１９８９～１９９０）的调查与研究，探讨了水化因子与水库鱼产力的关系。用反映鲢、鳙生长状况的综合生长指数（ＧＩ）作为水库鱼产力的指标。它与水化因子相关分析表明，总磷是山东省３８座水库鱼产力的主要影响因子。提出ＧＩ与总磷、总氮及电导率等水化因子的逐步回归方程关系非常显著。证明利用水化因子作为水库鱼产力的评价指标是可行的。并指出：同一水库的相同水化因子存在年间差异，其主要原因在于降雨量和水库进水量的不同，鉴于此．同一水库鱼产力也存在年间差异。  相似文献   

水库鱼产力评价标准与模式的研究   总被引：5，自引：0，他引：5       下载免费PDF全文

焦念志  李德尚 《海洋与湖沼》1993,24(1):79-86

本文在总结国内外已有成果的基础上,运用专家系统和灰色统计方法,初步建立了一套水库鱼产力评价的指标体系、指标权重体系和指标标准体系,首次给出了比较系统和具有普适意义的评价方案;并运用模糊数学方法建立了综合定量评价模式,从而在很大程度上解决了以往评价中由于多指标重迭、交错造成的难判、误判问题,为水库渔业资源的合理开发利用提供了比较科学的依据。  相似文献   

山东省大中型水库浮游生物研究──Ⅰ．浮游动物生态     

卢敬让  李德尚  周春生 《中国海洋大学学报(自然科学版)》1994,(1)

报道１９８９～１９９０年山东省３０多个大中型代表水库浮游动物的种类组成，种类频级、优势类群。主要种和生物量；统计分析掠食性与植食性浮游动物生物量，浮游动物与浮游植物生物量及浮游动物与代表水库营养状态指标的总磷，透明度和深度的关系。提出浮游动物个体越小，其生物量与水库营养水平关系越密切。  相似文献