Controls on Hydrocarbon Accumulation in Glauconitic Sandstone, Suffield Heavy Oil Sands, Southern Alberta
Controls on Hydrocarbon Accumulation in Glauconitic Sandstone, Suffield Heavy Oil Sands, Southern Alberta
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DOI：
10.1306/ad4616b5-16f7-11d7-8645000102c1865d
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发表时间：
1984-08
期刊：
影响因子：
3.5
通讯作者：
B. Tilley;F. Longstaffe
中科院分区：
文献类型：
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作者：
B. Tilley;F. Longstaffe
阿尔伯塔东南部苏菲尔德地区下白垩统海绿石质砂岩中油气分布受沉积学、构造和矿物学三个因素控制。海绿石砂岩由六个岩性相组成，解释为代表下-中滨面，中滨面，上滨面-前滨，后滨，沼泽和泻湖区的一个大陆，障壁-岛屿系统。沉积在前滨带（层状砂岩相）的沉积物具有最好的储集性能：孔隙度好，粘土含量低，横向连续性好。沉积在后滨带的生物扰动泥质砂岩储层质量较差：孔隙度低，粘土含量高，只有孤立的孔隙带。潮汐进口和/或后期河道沉积物穿过砂岩走向，形成储层中的不连续面。油气成藏机制是地层性的，但也受到构造的影响。在上部曼维尔沉积物沉积期间活动的深断层造成了差异沉降和沉积物的局部增厚。这种活动导致了不同相的明显侧向并置。部分海绿石砂岩形成了一个非常厚的海滩-滨面序列（厚达45米或148英尺）。亚白垩纪单元的断层可能控制了海绿石砂岩沉积过程中的沉降速率和沉积物积累量。粘土（主要是高岭石）的丰度在很大程度上控制着储层质量。泥质后滨砂岩中含有大量的碎屑高岭石，是不良储集层;干净的前滨沉积是良好储集层。孔隙度和渗透率在干净砂岩中仅因形成高岭石和石英等成岩相而略有降低。在湿法正燃开采过程中，高岭石的迁移和二氧化硅的溶解-再沉淀会造成地层损害。
Hydrocarbon distribution in the Lower Cretaceous Glauconitic sandstone in the Suffield area of southeastern Alberta is controlled by three factors: sedimentology, structure, and mineralogy. The Glauconitic sandstone consists of six lithological facies interpreted to represent the lower-middle shoreface, middle shoreface, upper shoreface-foreshore, backshore, marsh, and lagoonal zones of a progradational, barrier-island system. Sediment deposited in the foreshore zone (laminated sandstone facies) has the best reservoir qualities: good porosity, low clay content, and good lateral continuity. The bioturbated, argillaceous sandstone, deposited in the backshore zone, has poor reservoir qualities: low porosity and high clay content with only isolated porous zones. Tidal inlet a d/or later stage fluvial channel deposits cutting through the sandstone trend form discontinuities in the reservoir. The hydrocarbon trapping mechanism is stratigraphic but with some structural influence. Deep faults, active during the deposition of upper Mannville sediments, caused differential subsidence and local thickening of sediment. This activity resulted in the apparent lateral juxtaposition of different facies. Parts of the Glauconitic sandstone form an exceptionally thick beach-shoreface sequence (up to 45 m or 148 ft thick). Faulting of sub-Cretaceous units may have controlled the rate of subsidence and the amount of sediment accumulation during deposition of the Glauconitic sandstone. The abundance of clay, mostly kaolinite, largely controls reservoir quality. Argillaceous backshore sandstones, which contain abundant detrital kaolinite, are poor reservoirs; clean foreshore deposits are good reservoirs. Porosity and permeability are only slightly reduced in the clean sandstone by formation of diagenetic phases such as kaolinite and quartz. During the wet forward-combustion recovery process, migration of kaolinite and dissolution-reprecipitation of silica could cause formation damage.