塔河西部奥陶系古岩溶小流域的划分及其地质意义

The division of the Ordovician paleokarst small watershed in the west of Tahe and its geological significance

吕艳萍,姜应兵,高济元,蔡忠贤

中国石化西北油田分公司，新疆 乌鲁木齐 830011 2中国地质大学（武汉）构造与油气资源教育部重点实验室，湖北 武汉 430074 中国地质大学（武汉）资源学院，湖北 武汉 430074

Northwest Oilfield Company, SINOPEC, Urumqi 830011, China Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education, China University of Geosciences, Wuhan 430074, China School of Earth Resources, China University of Geosciences, Wuhan 430074, China

近年来，塔河西部斜坡区中下奥陶统发现了广泛发育的碳酸盐岩缝洞储集体，且不同地区呈现明显的差异性。岩溶水作为主导岩溶含水介质形成与发育的关键要素，其空间分布和分区差异性研究尤为关键。基于三维地震资料，通过地震属性提取技术恢复了塔河西部斜坡区中下奥陶统顶部的古水系结构，并依据SL 653—2013《小流域划分及编码规范》进行了岩溶小流域划分，利用水道平均密度和地表河网密度等水文学参数开展了岩溶小流域分区评价。研究结果表明：塔河西部斜坡区可划分出10个亚流域、43个小流域，其中，亚流域Ⅳ和Ⅵ的完整型小流域具有相对有利的水文学条件。岩溶小流域的划分及评价为岩溶储层分区认识和精细开发提供了重要依据。

n recent years, extensively developed carbonate fractured-vuggy reservoirs have been discovered in the Middle-Lower Ordovician in the western slope of Tahe area. The reservoirs in different regions show obvious differences. Karst water is a key factor for the formation and development of karst water-bearing media. Therefore, the study on karst reservoirs spatial distribution and regional differences is particularly important. Based on 3D seismic data, the structure of ancient water system at the top of the Ordovician in western slope of Tahe area was rebuilt by seismic attributes extraction technology. The karst small watershed was divided according to the specification for small watershed division and coding SL 653-2013, and the zonation evaluation of karst small watershed was carried out by using the average density of watercourse and the density of surface river network. The results show that the western slope of Tahe area can be divided into 10 sub-watersheds and 43 small watersheds, among which the intact small watershed of the sub-watershed Ⅳ and Ⅵ have relatively favorable hydrological conditions. The division and evaluation of karst small watershed provide an important basis for the zoning recognition and fine development of karst reservoirs.

10.6056/dkyqt202104002