An Analysis of U.S. and World Oil Production Patterns Using Hubbert-Style Curves

A quantitative analytical method, using a spreadsheet, has been developed that allows the determination of values of the three parameters that characterize the Hubbert-style Gaussian error curve that best fits the conventional oil production data both for the U.S. and the world. The three parameters are the total area under the Gaussian, which represents the estimated ultimate (oil) recovery (EUR), the date of the maximum of the curve, and the half-width of the curve. The best fit is determined by adjusting the values of the three parameters to minimize the root mean square deviation (RMSD) between the data and the Gaussian. The sensitivity of the fit to changes in values of the parameters is indicated by an exploration of the rate at which the RMSD increases as values of the three parameters are varied from the values that give the best fit. The results of the analysis are as follows: (1) the size of the U.S. EUR of oil is suggested to be 0.222 × 10¹² barrels (0.222 trillion bbl) of which approximately three-fourths appears to have been produced through 1995; (2) if the world EUR is 2.0 × 10¹² bbl (2.0 trillion bbl), a little less than half of this oil has been produced through 1995, and the maximum of world oil production is indicated to be in 2004; (3) each increase of one billion barrels in the size of the world EUR beyond the value of 2.0 × 10¹² bbl can be expected to result in a delay of approximately 5.5 days in the date of maximum production; (4) alternate production scenarios are presented for world EURs of 3.0 and 4.0 × 10¹² bbl.     

阿尔及利亚三叠盆地、韦德迈阿次盆地石油地质特征及油气勘探中应注意的问题

阿尔及利亚在区域上由两大单元组成,北部为撒哈拉阿特拉斯褶皱带,南部为撒哈拉地台。油气田主要分布在撒哈拉地台的三叠盆地和伊利兹盆地。在三叠盆地内已发现50多个油田和37个气田,石油地质储量达23×108t,天然气地质储量达4×1012m3。油气田中以超巨型的哈西迈萨乌德油田和哈西勒迈勒凝析气田最为著名。三叠盆地的烃源岩主要为下志留统Graptolitic组黑色页岩;韦德迈阿次盆地的烃源岩主要为志留系Fegaguria组深灰色—黑色富有机质泥岩。三叠盆地与韦德迈阿次盆地的储盖条件都比较优越,但油藏的埋深较大,且位于沙漠地区,在勘探上应注意“西气东油”的油气分布特征和坚持“立体勘探”的方法。     

利用MODIS fAPAR傅立叶时间序列分析研究植被光合作用活动对净辐射和降雨的响应：青藏高原个例研究

气候变化对植被动力学有非常大的影响。为了定量描述气候变化对植被的影响，文章利用MODIS fAPAR 数据和NCEP 的净辐射和降雨再分析数据对青藏高原地区气候变化对植被的影响进行了时间序列分析。研究所用的数据时间跨度为2000年至2005年。首先利用NCEP 再分析数据建立了干旱度因子的时间序列，为了与MODIS fAPAR 具有相同的时间采样间隔，由NCEP的日净辐射和日降雨量得到每8天的平均净辐射和8日降雨的和。根据一定时间间隔的净辐射与降雨量的比可以用来衡量相对于可利用水分的剩余能量，因此该比值也是干旱灾害的度量。其次，对MODIS fAPAR 的傅立叶时间序列分析提供了两个植被光合作用对干旱相应的因子，即fAPAR的年平均值及其年振幅值。在时间和空间尺度上对植被光合作用活动与干旱指数之间的关系进行了定量分析。对湿年和干年之间的响应差异进行了比较。研究表明较干地区对气候变化的响应最为显著。分析应该扩展到更长的时间跨度以便更加有效地在时间和空间尺度上评估气候变化对植被动力学的影响。