Scenario simulations of CO2 injection feasibility, plume migration and storage in a saline aquifer, Scania, Sweden

Deep saline aquifers have large capacity for geological CO₂ storage, but are generally not as well characterized as petroleum reservoirs. We here aim at quantifying effects of uncertain hydraulic parameters and uncertain stratigraphy on CO₂ injectivity and migration, and provide a first feasibility study of pilot-scale CO₂ injection into a multilayered saline aquifer system in southwest Scania, Sweden. Four main scenarios are developed, corresponding to different possible interpretations of available site data. Simulation results show that, on the one hand, stratigraphic uncertainty (presence/absence of a thin mudstone/claystone layer above the target storage formation) leads to large differences in predicted CO₂ storage in the target formation at the end of the test (ranging between 11% and 98% of injected CO₂ remaining), whereas other parameter uncertainty (in formation and cap rock permeabilities) has small impact. On the other hand, the latter has large impact on predicted injectivity, on which stratigraphic uncertainty has small impact. Salt precipitation at the border of the target storage formation affects CO₂ injectivity for all considered scenarios and injection rates. At low injection rates, salt is deposited also within the formation, considerably reducing its availability for CO₂ storage.     

SIMPLE MEASUREMENTS OF SOIL SURFACE MICRORELIEF CHARACTERISTICS1

ABSTRACT: Soil surface roughness and the topographic orientation of microrelief influence runoff and water storage. Distances measured following the surface of the microrelief and horizontally across the area with the microrelief can be used with the number of microridges or microhills to estimate the average cross-sectional areas of the depression, the microslope angles, and crest heights. Microridge sideslope angles which effect the rate of runoff were estimated reasonably well in field plots by the method.     

CO2SINK—From site characterisation and risk assessment to monitoring and verification: One year of operational experience with the field laboratory for CO2 storage at Ketzin, Germany

The CO₂SINK pilot project at Ketzin is aimed at a better understanding of geological CO₂ storage operation in a saline aquifer. The reservoir consists of fluvial deposits with average permeability ranging between 50 and 100 mDarcy. The main focus of CO₂SINK is developing and testing of monitoring and verification technologies. All wells, one for injection and two for observation, are equipped with smart casings (sensors behind casing, facing the rocks) containing a Distributed Temperature Sensing (DTS) and electrodes for Electrical Resistivity Tomography (ERT). The in-hole Gas Membrane Sensors (GMS) observed the arrival of tracers and CO₂ with high temporal resolution. Geophysical monitoring includes Moving Source Profiling (MSP), Vertical Seismic Profiling (VSP), crosshole, star and 4-D seismic experiments. Numerical models are benchmarked via the monitoring results indicating a sufficient match between observation and prediction, at least for the arrival of CO₂ at the first observation well. Downhole samples of brine showed changes in the fluid composition and biocenosis. First monitoring results indicate anisotropic flow of CO₂ coinciding with the “on-time” arrival of CO₂ at observation well one (Ktzi 200) and the later arrival at observation well two (Ktzi 202). A risk assessment was performed prior to the start of injection. After one year of operations about 18,000 t of CO₂ were injected safely.     

MAN ON THE HYDROLOGIC CYCLE1

ABSTRACT: Man is the one biological factor that can either make environment fit his needs or unknowingly ruin it. The major phases of the hydrologic cycle, in which man can interfere are: precipitation, storage and evaporation. A change m any one phase will generally cause modification to the other phases of the cycle: the only certainity is that the water balance will indeed balance.     

洪湖分蓄洪区启用的若干问题研究

１９９８年长江供水对沿江大堤及分蓄区都是一场验,同时也使人们对一些老问题的严重性和新问题的紧迫性和加深了认识。本文就洪湖分洪工程存在的问题,特大洪水条件下分洪区启用时的口门位置及其分洪区启用前后的有关重要问题进行了,提出了相应对策。文中涉及的问题对其它分蓄洪也有参考意义。     

发射药贮存寿命预测技术研究进展

简述了发射药贮存寿命试验所用的自然环境长期贮存试验监测法和加速寿命试验方法的现状,对发射药寿命评价与预测所用的人工神经网络技术和计算机模拟技术进行了分析,阐明了现有技术的优缺点,论述了发射药贮存寿命试验与评价技术的发展趋势.     

次氯酸钠药剂在不同水厂的应用

次氯酸钠药剂在水务行业应用广泛,常被用作消毒剂,对于保障水质具有重要的作用.介绍了近6年来次氯酸钠消毒剂在水务行业的应用情况,以期为不同性质水厂的运行提供参考.     

近30年玛纳斯河流域土地利用/覆被变化对植被碳储量的影响

天然植被退化,部分转变为人工植被和人类聚居区是干旱区绿洲过程的重要表现之一,而目前对土地利用变化影响植被碳储量的机制还不十分清楚。论文尝试采用CASA模型及1976—2007年4期9月份Landsat卫星影像估算玛纳斯河流域9种植被类型的净初级生产力,并通过植物枯损模型估算了流域内植被碳密度,进而估算出流域内各类型植被碳储量,最后分析土地利用/覆被类型间的转移对植被碳储量的影响。结果表明,在1976—2007年间,受农作物种植结构及品种变化影响,绿洲农田植被碳密度变化较大;同期流域植被碳储量共增加了50.50×104t C,其中林地被乱砍乱伐,灌木林地、天然牧草地退化为荒草地使得流域植被碳储量减少了1.21×104t;林地、农田、荒草地以及未利用地之间的转移使得流域植被碳储量总共增加了18.52×104t C。研究结果显示,流域内植被碳储量总体呈增加趋势,且农田是影响流域植被碳储量的主要因素。     

某橡胶减振垫加速贮存老化试验及寿命预测

分析了减振垫的贮存环境应力及失效机理,建立了减振垫的性能退化模型及加速模型。选取直接描述减振垫工作特性的品质因数为性能退化参数,通过加速老化试验,在较短的试验时间内确定了减振垫的贮存寿命。     

地下油罐泄漏区污染源的自动识别

地下油罐泄漏隐蔽性大,不易被及时发现,而且泄漏出的烃类化合物毒性强,对地下水会造成严重污染.为了对某一地下油罐污染源位置和强度进行准确识别,本研究结合现场调查结果,建立了该地下油罐泄漏区的石油污染物反应运移模型.在基本确定污染源泄漏区范围的前提下,进一步建立地下油罐泄漏区污染源的识别模型,并利用遗传算法对泄漏区污染源的位置和泄漏强度进行了自动识别,进而通过参数敏感性分析来评价和比较不同参数对污染物运移结果的影响.结果表明,运移模型中与地下水流场变化相关的特征参数（如开采量、水力坡度、渗透系数等）对污染物运移结果的影响相对比较明显.对于污染源来说,研究不同污染组分在含水层中的化学和生物化学变化显得尤为重要.