阜新五龙刘家区煤层气开发前景浅析   总被引：1，自引：0，他引：1  

陈兆山  曹立刚 《中国煤田地质》2004,16(5):21-24

为了进一步开发阜新五龙刘家区煤层气，对研究区煤层气地面开发与井下瓦斯抽放进行了探讨，并着重对其开发前景及经济效益进行了分析，其结论是投资回收期较短、经济效益好、投资风险较小。是煤炭枯竭城市经济转型的良好项目之一。  相似文献   

强污染单历元GPS形变信号的提取和粗差识别   总被引：6，自引：0，他引：6  

王坚  高井祥  苗李莉 《武汉大学学报(信息科学版)》2004,29(5):416-419

阐述了小波分析技术用于强污染GPS单历元形变信号处理的基本原理及其实现方法。以含少量粗差的低信噪比形变信号为例 ,研究了基于Mallat分解和合成算法 ,分离信号趋势项并进行粗差识别的技术。采用小波软阈值降噪的方法去除强污染数据中的随机噪声 ,降噪效果远好于中值滤波。最后对识别的粗差信息进行线性修复 ,获得了令人满意的形变信号  相似文献   

Framing realistic river rehabilitation targets in light of altered sediment supply and transport relationships: lessons from East Gippsland, Australia     

Andrew P. Brooks  Gary J. Brierley 《Geomorphology》2004,58(1-4):107-123

Since European settlement, the Cann River in East Gippsland, Victoria has experienced a 700% increase in channel capacity, a 150-fold increase in the rate of lateral channel migration, a 45-fold increase in bankfull discharge and a 860-fold increase in annual sediment load. Over the last century, and primarily the last 40 years, channel incision has removed the equivalent of around 1500 years of floodplain deposition. A numerical floodplain evolution model is presented which suggests that under a best case scenario, infilling the incised channel trench will take 31,000 years and this is predicated on the full recovery of the immediate riparian vegetation and the in-channel loading of woody debris. The asymmetry in the recovery time following rapid channel change, compared with the original deposition of the material, is explained by a combination of the sediment-starved character of the catchment and the altered hydraulic conditions within the channel, principally associated with the role of woody debris. These factors have major implications for geomorphic recovery potential, constraining what can be realistically achieved in river rehabilitation.  相似文献   

桩基取芯检测施工工艺     

胡文华  黄朝阳  张晓东 《福建地质》2002,21(3):166-168

介绍了福宁高速公路部分高架桥跨海大桥桩基钻探取芯检测施工工艺，研究采用了φ89mm套管作钻杆，单动双管钻具钻进，从而保证了钻孔垂直度及砼芯采取率的较高质量要求。  相似文献   

油层不同开采时期原油组分变化特征   总被引：1，自引：0，他引：1  

陈祖林  朱扬明  陈奇 《沉积学报》2002,20(1):169-173

运用有机地球化学分离、分析技术对取自塔里木盆地的东河、塔中和轮南油田不同时期开采出的原油样品进行剖析,研究其宏观组成和微观分子在时空上的变化规律。分析结果表明,原油饱 /芳比值随开采时间的推移呈下降的趋势;饱和烃与非烃 +沥青质的含量变化有很好的相关性。随着开采时间的增长,原油中正构烷烃的主峰碳数后移,原油的轻 /重组分比降低。原油碱性氮、有机酸等非烃类化合物随开采时间的推移也呈降低的趋势。这些变化与原油在驱替过程中的自然色层吸附作用机理和原油中各种组分的相互作用关系有关。该项研究对于深入探索驱油机理、预测原油润湿性和提高采收率具有重要的实际意义。  相似文献   

Reservoir lifetime and heat recovery factor in geothermal aquifers used for urban heating   总被引：1，自引：0，他引：1  

Alain C. Gringarten 《Pure and Applied Geophysics》1978,117(1-2):297-308

Simple models are discussed to evaluate reservoir lifetime and heat recovery factor in geothermal aquifers used for urban heating. By comparing various single well and doublet production schemes, it is shown that reinjection of heat depleted water greatly enhances heat recovery and reservoir lifetime, and can be optimized for maximum heat production. It is concluded that geothermal aquifer production should be unitized, as is already done in oil and gas reservoirs.Nomenclature a distance between doublets in multi-doublet patterns, meters - A area of aquifer at base temperature, m² drainage area of individual doublets in multidoublet patterns, m² - D distance between doublet wells, meters - h aquifer thickness, meters - H water head, meters - Q production rate, m³/sec. - r _e aquifer radius, meters - r _w well radius, meters - R _g heat recovery factor, fraction - S water level drawdown, meters - t producing time, sec. - T aquifer transmissivity, m²/sec. - v stream-channel water velocity, m/sec. - actual temperature change, °C - theoretical temperature change, °C - water temperature, °C - heat conductivity, W/m/°C - _r rock heat conductivity, W/m/°C - _aC_a aquifer heat capacity, J/m³/°C - _aC_r rock heat capacity, J/m³/°C - _WC_W water heat capacity, J/m³/°C - aquifer porosity, fraction  相似文献   

松辽盆地中部地区古构造成因机制分析     

袁炳存  兰廷泽  钱奕中 《地球科学》1986,(3)

本文利用“逐层恢复法”对松辽盆地中部地区一百多口主要探井进行古厚度恢复工作。编制了古构造图、压实量等值线图、古厚度差值等值线图,并在此基础上对该区古构造特征及其形成机制提出了新的认识。  相似文献   

Evaluating uncertainty in Landsat-derived postfire recovery metrics due to terrain,soil, and shrub type variations in southern California     

Emanuel A. Storey  Douglas A. Stow  Dar A. Roberts 《地理信息系统科学与遥感》2020,57(3):352-368

ABSTRACT

Temporal trajectories of apparent vegetation abundance based on the multi-decadal Landsat image series provide valuable information on the postfire recovery of chaparral shrublands, which tend to mature within one decade. Signals of change in fractional shrub cover (FSC) extracted from time-sequential Normalized Difference Vegetation Index (NDVI) data can be systematically biased due to spatial variation in shrub type, soil substrate, or illumination differences associated with topography. We evaluate the effects of these variables in Landsat-derived metrics of FSC and postfire recovery, based upon three chaparral sites in southern California which contain shrub community ecotones, complex terrain, and soil variations. Detailed validations of prefire and postfire FSC are based on high spatial resolution ortho-imagery; cross-stratified random sampling is used for variable control. We find that differences in the composition and structure of shrubs (inferred from ortho-imagery) can substantially influence FSC-NDVI relations and impact recovery metrics. Differences in soil type have a moderate effect on the FSC-NDVI relation in one of the study sites, while no substantial effects were observed due to variation of terrain illumination among the study sites. Arithmetic difference recovery metrics – based on NDVI values that were not normalized with unburned control plots – correlate in a moderate but significant manner with a change in FSC (R ² values range 0.47–0.59 at two sites). Similar regression coefficients resulted from using Landsat visible reflectance data alone. The lowest correlations to FSC resulted from Soil-Adjusted Vegetation Index (SAVI) and are attributed to the effects of the soil-adjustment factor in sparsely vegetated areas. The Normalized Burn Ratio and Normalized Burn Ratio 2 showed a moderate correlation to FSC. This study confirms the utility of Landsat NDVI data for postfire recovery evaluation and implies a need for stratified analysis of postfire recovery in some chaparral landscapes.  相似文献   

伴生金的工艺矿物学研究方法     

都安治 《矿物学报》2001,21(3):528-530

本文讨论了开展伴生金工艺矿物学研究的一些新技术与方法，如相态分析法、工艺配方法、理想回收率计算法及金矿物粒度测定法等。上述方法可不同程度地适用于岩金乃至于砂金的工艺矿物学研究。  相似文献   

复杂断块油田提高采收率的途径     

汪深 《江苏地质》2001,25(4):234-237

由于采收率是可采储量与地质储量的比值，在地质储量一定的条件下，采收率的提高意味着可采储量的增加，在地质储量及可采储量都在变化时，我们不应拘泥于采收率数值的大小，而要在一定的经济技术条件下，尽可能通过各种增产措施来提高有经济效益的可采储量。  相似文献