陆架边缘三角洲研究进展及实例分析

发布时间：2018-10-12 21:10

【摘要】：自上世纪90年代以来,发育在大陆架边缘的一种特殊类型的三角洲(shelf-edge delta),因其厚度大,分布面积广,储层物性好,常常与陆坡深水扇体伴生,成藏条件好等特点而引起了广泛关注,成为当前国际沉积学界研究的热点和油气勘探新领域。陆架边缘三角洲一般形成于相对海平面下降或低位时期,主要受控于物源供给、可容纳空间和气候变化,并受到陆坡构造活动影响;也可发育在高位时期,受到波浪与潮汐的影响。前人提出了利用陆架边缘迁移轨迹预测深水沉积和基于陆架斜坡发育模式预测深水沉积的模型,即强烈抬升的陆架边缘迁移轨迹、强烈加积的陆架斜坡发育模式,对应的深水区物质传输体系为泥质;水平—轻微下降的陆架边缘迁移轨迹、强烈前积的陆架斜坡发育模式,预示着大量砂体被搬运至深水区;轻微抬升的陆架边缘迁移轨迹、加积与前积的陆架斜坡发育模式,暗示深水沉积砂体发育介于上述二者陆架边缘迁移与深水扇预测模式之间。陆架边缘三角洲—深水扇规模砂体毗邻优质烃源岩,具备多种类型的油气运移通道,成藏条件良好,是油气勘探的有利领域。实例分析表明:渐新世珠海组沉积时期构造相对稳定,在古珠江充足的供源条件下,南海北坡珠江口盆地鹤山凹陷发育陆架边缘三角洲并伴随陆架不断向海迁移而不断进积,S型前积体不断向海迁移,并在晚期发育下切谷及大型盆底扇沉积。鹤山凹陷珠海组沉积时期发育水平—轻微下降的陆架边缘迁移轨迹,对应于强烈前积的陆架斜坡发育模式,在珠海组沉积晚期发育较大规模叠合连片深水扇富砂沉积体系,是研究区极好的潜在油气勘探目标。
[Abstract]:Since the 1990s, a special type of delta developed on the edge of the continental shelf (shelf-edge delta),) is often associated with deep-water fans on the continental slope because of its large thickness, wide distribution area and good reservoir physical properties. The characteristics of good reservoir forming conditions have attracted wide attention and become a hot spot in the international sedimentological research and a new field of oil and gas exploration. Continental shelf marginal deltas are generally formed during the relative sea level decline or low levels, mainly controlled by the provenance supply, capable of accommodating spatial and climatic changes, and affected by slope tectonic activity, or developed at high levels. Affected by waves and tides. Previous studies have proposed a model for predicting deep-water deposition using shelf marginal migration trajectory and prediction of deep-water deposition based on shelf slope development model, that is, strongly uplifted shelf marginal migration trajectory and strongly accretive continental shelf slope development model. The corresponding material transport system in the deep water area is muddy, the lateral migration trajectory of the continental shelf edge is reduced slightly, and the strongly accumulated continental shelf slope development pattern indicates that a large number of sand bodies are transported to the deep water area. The continental shelf slope development model of accretion and forward-accumulation suggests that the development of deep-water sedimentary sandbodies lies between the marginal migration of continental shelf and the prediction model of deep-water fan. The continental shelf margin delta-deep water fan scale sand body is adjacent to high quality source rock and has a variety of hydrocarbon migration channels and good reservoir forming conditions. It is a favorable field for oil and gas exploration. The analysis of examples shows that the structure of the Oligocene Zhuhai formation is relatively stable during the sedimentary period, and under the condition of abundant supply of the paleo-Pearl River, The Heshan sag in the Pearl River mouth basin on the northern slope of the South China Sea developed a marginal delta along with the continuous migration of the continental shelf to the sea, and the S-type programe migrated to the sea, and developed in the late stage of the lower cutting valley and the large pelvic floor fan deposits. In the depositional period of the Zhuhai formation in Heshan Sag, the horizontal and slight decline of the continental shelf margin migration track corresponds to the strong forward accumulation model of the continental shelf slope, and in the late sedimentary period of the Zhuhai formation, a large scale superimposed deep-water fan sand rich sedimentary system was developed. It is an excellent potential oil and gas exploration target in the research area.
【作者单位】：中国石油大学(北京)地球科学学院;中海石油(中国)深圳分公司研究院;
【基金】：国家科技重大专项子项目(2011ZX05025-005-02) 国家自然科学基金项目(41272133)~~
【分类号】：P618.13

【相似文献】