摘要： 东河砂岩是一套覆盖广泛的海侵初期的沉积产物, 但不是一个等时沉积体, 相当于晚泥盆世晚期至早石炭世早期沉积, 具体沉积时间各地有差异。东河砂岩具有海侵初期填平补齐的特征, 其沉积相决定于海侵的速度、沉积物的供给和海侵前的古地貌。塔北地区受塔北古隆起的阻挡, 海水在古隆起周围滞留时间较长, 又有较粒的物源供给, 其沉积产物主要是滨岸海滩沉积: 塔中地区由于地形复杂, 沉积类型也比较复杂, 底部砾岩段为河流相沉积, 而块状砂岩段和砂砾岩段为河口湾和滨岸海滩沉积, 不同段在成分、分选性和粒级上有较大的差异: 塔里木盆地其他低平地区主要是海侵期快速的滨岸和陆架沉积。受沉积因素影响,东河砂岩有效储层的分布具有地域性, 除沉积因素外, 低的地温梯度和短期的深埋藏也是优质储层发育的重要控制因素。
关键词:
东河砂岩,
海侵,
古隆起,
有效储层,
海滩,
沉积构造
Abstract: The Donghe Sandstone was broadly deposited in the early stage of the marine transgression, but it is not an isochronous stratigraphic unit It was deposited from the late Late Devonian to the early Early Carboniferous with various depositional ages in different areas. It has an outstanding feature of filling and leveling up. Its sedimentary facies were controlled by the marine transgression speed, the sediments supply and the pre-transgression palaeotopography. In the northern Tarim Basin, which was blocked by the Tabei paleo uplift, the seawater stayed around the paleo uplift for a long period, combined with this, the coarse grained sediments supply, the shore beach deposits were developed. In the central Tarim Basin, however, the sedimentary facies are complex because of the complex topographic setting. Fluvial deposits were developed in the basal conglomerate member, and estuary and shore beach deposits in the massive sandstone member and the sandy conglomerate member. Different members have their own characteristics of composition, sorting and grain size While in other gentle slope and flat areas of the Tarim Basin, rapidly-deposited shore and shelf sediments were developed during the transgressive period Controlled by the sedimentary environments, the effective reservoirs of the Donghe Sandstone are distributed in certain zones. Besides the sedimentary factors, the low paleogeothermal gradient and the short-term deep burial history are the other two crucial factors controlling the development of the high-quality Donghe Sandstone reservoir.
Key words:
Donghe Sandstone,
marine transgression,
paleo uplift,
effective reservoir,
beach,
sedimentary structures
中图分类号:
顾家裕, 张兴阳, 郭彬程. 塔里木盆地东河砂岩沉积和储层特征及综合分析[J]. 古地理学报, 2006, 8(3): 285-294.
Gu Jiayu, Zhang Xingyang, Guo Bincheng. Characteristics of sedimentation and reservoir of the Donghe Sandstone in Tarim Basin and their synthetic analysis[J]. JOPC, 2006, 8(3): 285-294.