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本文论述了英国北海南部Sole Pit地区赤底统砂岩中裂缝和填孔的胶结物。本文采用标准岩石薄片观察和扫描电镜分析及流体包裹体的显微测温技术,研究了砂岩胶结物的地层学特征并描述了胶结物的特征。此外还综合运用岩相学和流体包裹体显微测温技术来确定北海南部区域胶结作用和天然气运移作用发生的时间。 Sole Pit地区的地质历史类似于北海南部的其它地区。风成沉积物形成的上二叠赤底统砂岩终止于蔡希斯坦统的海侵作用。在白垩纪前该地区处于快速沉降阶段,白垩纪时的抬升运动影响了Sole Pit地区以及其它地区,如Broad Fourteens盆地。这种抬升持续到白垩纪,随后发生了短暂的沉降,接着又在白垩纪末期发生了抬升作用并一直持续到第三纪。 当绘出埋藏热历史图后,流体包裹体和岩石学研究结果表明石英胶结物沉淀发生在超过一定埋藏深度之后。石英矿化带在深埋藏阶段非常普遍,而且在Sole Pit地区的抬升时代也非常普遍,并导致赤底统砂岩出现大量的裂缝。白云岩沉积发生在深埋藏成岩时期,并终止于裂缝大量出现时。硫酸盐矿物(硬石膏和重晶石)是该地区抬升反转时期的主要沉积物。由于一些胶结物中硬石膏溶液包裹体和部分石英流体包裹体中存在有烃类气体,故气体的运移发生在抬升时期,而裂缝则是天然气运移的通道。
This article discusses the cements of fissures and fills in the red-bedded sandstones of the Sole Pit area in southern British North Sea. In this paper, the stratigraphic characteristics of sandstone cements and the characteristics of cements are described by the observation of standard rock slices and scanning electron microscopy and the microscopic temperature measurement of fluid inclusions. In addition, petrographic and fluid inclusions microscopic temperature measurement techniques are also used to determine the occurrence of cementation and gas migration in the northern North Sea. The geological history of the Sole Pit region is similar to the rest of the North Sea. The Upper Permian Triassic sandstones formed by the aeolian sediments terminate in the transgression of the Tsai Stananites. The area was rapidly subsided before the Cretaceous and the Cretaceous uplift affected the Sole Pit area and beyond, such as the Broad Fourteens Basin. This uplifting continued into the Cretaceous, followed by a brief subsidence followed by uplift in the late Cretaceous that continued into the Tertiary. When the burial history was plotted, the fluid inclusions and petrology results show that the quartz cementation deposits occur beyond a certain depth of burial. Quartz mineralization is very common during deep burial, and the uplift in the Sole Pit area is also very common and leads to a large number of fractures in the Tethyan sandstone. Dolomite deposition occurred during deep-burial diagenesis and ended in the presence of a large number of fractures. Sulfate minerals (anhydrite and barite) are the major deposits in the region uplifted during the inversion period. Gas migration occurs during the uplift period due to the presence of hydrocarbon gases in anhydrite inclusions and some quartz fluid inclusions in some cements, whereas fractures are the channels through which natural gas migrates.