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自从1959年发现Croningen天然气田以来,中欧地堑沉积的赤底统(萨克森阶)成为在中欧及西北欧的石油及天然气产区中寻找天然气的极好目标.迄今在萨克森阶探明的总储量超过了4×10~(12)m~3(Vn).而荷兰的海上、陆上和英国北海区域的储量占了其中的大部分.这些气田及已探明储量的不均匀分布反映了中欧地堑赤底统一个典型特征:气田几乎全部位于盆地南缘,最大的则主要集中在西部.迄今为止,在北缘只发现了很少几个气田.在赤底统的杂岩层中.找到了约100个气田.其中,既有优良的大型天然气田,如Gronigen, Leman、Indefatigable, Viking, Salzwedel-Peckensen等气田,亦有一群中小型气田.按地域划分或按岩系分类,天然气田分别处于上石炭系,蔡希斯坦统和下三叠系中,其天然气产状显示了与赤底统岩系的成因联系.这里所有气田的一个重要特征是其成分可由几乎纯烃变化到几乎为纯氮.甲烷差不多是气体中碳氢化合物的唯一组分.尚值得一提的次要成分是汞和氦.初看上去,赤底统中天然气田形成所要求的条件似乎十分理想:1.煤含量丰富的上石炭系的气源岩在赤底统中分布十分广泛.2.在大多数情况下,萨克森阶含油砂岩层紧邻其上部.3.在上盘中蔡希斯坦-萨林纳统形成理想的盖层.4.不同性质的构造活动创造了有利的构造条件.然而,在进一步的研究之后,其局限性就暴露了出来,对具体的情况还需要进行细致的判断.母岩的生气潜能受着局部变化的影响,而且,控制着天然气形成的、对母岩产生着影响的地热,在空间和时间上变化很大.此外,含油层的质量差异亦十分明显,这首先是由于侧向和垂向的沉积条件的变化所致,其次亦是由于沉积后的变化造成.蔡希斯坦盆地边缘的部分剥蚀乃至完全缺失(这是由萨林纳统的尖灭所引起的)引起了气体向上盘的运移.构造运动不仅有利于倾斜层的形成,而且更重要的是:在较新地质时期,既造成了天然气田的广泛分布,还造成了对气田的破坏.
Since the discovery of the Croningen gas field in 1959, the Chester-Holocene (Saxony) deposition of the Central Europe has become an excellent target for finding natural gas in the oil and gas producing areas of Central and North-Western Europe. To date, the total proven reserves in the Saxony Over 4 × 10 ~ (12) m ~ 3 (Vn), while the Netherlands has a large portion of its reserves offshore and on land as well as in the North Sea of Britain.The uneven distribution of these fields and their proved reserves reflects that Central Europe A typical feature of the graben red sole: the gas fields are almost entirely located in the southern margin of the basin, while the largest are concentrated in the west. So far, only a few gas fields have been found in the northern margin. There are about 100 gas fields, of which there are excellent large-scale natural gas fields such as Gronigen, Leman, Indefatigable, Viking and Salzwedel-Peckensen, and a group of small and medium-sized gas fields. In the Upper Carboniferous, the Zeiss Stanan, and the Lower Triassic, the natural gas production shows a genetic relationship with the diorite series, and an important feature of all gas fields here is that their composition can vary from almost pure hydrocarbons to nearly pure Methane is almost the only component of hydrocarbons in the gas, and the most notable secondary constituents are mercury and helium At first glance, the conditions required for the formation of gas fields in the Tethys seem to be ideal: 1. Coal content The rich Upper Carboniferous gas source rocks are widely distributed in the Red Terroir. (2) In most cases, the Saxonian oil-bearing sandstone layer is immediately adjacent to the upper part of the sandstone. (3) In the upper plate, the Tsai Stan-Salinas formation The ideal caprock.4 The tectonic activities of different nature have created favorable tectonicconditions.However, after further research, the limitations have been revealed and the concrete conditions need to be carefully judged. Potential is affected by local changes, and the geothermal heat that controls the formation of natural gas that affects the parent rock varies greatly in space and time. In addition, the difference in mass of the oil-bearing formation is also evident, first of all because To vertical and vertical depositional conditions, and secondly to post-depositional variability. Part of the erosion or even complete absence of the edges of the Tsaištam Basin, caused by the extinction of the Salinas, Gas up plate . Migration tectonic movement is not only conducive to the formation layer is inclined, and more importantly: in newer geological period, both caused by the widespread natural gas fields, also caused damage to the gas field.