柴达木盆地西部地区致密油地质特征及勘探领域

发布时间：2018-08-25 11:01

【摘要】：应用大量钻井和实验分析资料,对柴达木盆地西部地区(简称柴西地区)致密油沉积环境、源储及配置组合地质特征进行综合分析,预测出四大致密油勘探领域。柴西地区自古近纪以来受青藏高原持续挤压隆升作用影响,沉积环境具三大显著特征:(1)继承性的古斜坡和凹隆相间的古地貌;(2)相对湿润到干旱频繁交替变化的古气候;(3)高频震荡升降演化的湖平面和古盐度。在其控制下,古近纪末期至新近纪早期发育了两套规模大、生烃效率高的主力烃源岩,发育了碎屑岩和碳酸盐岩两类规模致密储集层,形成了源储间互、源储共生和源储侧交3种有利致密油源储组合类型。评价预测结果揭示柴西地区存在咸化湖泊碳酸盐岩、浅湖滩坝砂岩、三角洲前缘砂岩和深湖重力流砂岩4类致密油储集层类型及勘探领域,时空分布具层位集中、规律性强、有利面积大等特点,其中咸化湖泊碳酸盐岩和浅湖滩坝砂岩致密油勘探潜力最大。
[Abstract]:Based on a large number of drilling and experimental data, the geological characteristics of tight oil sedimentary environment, source storage and configuration combination in the western Qaidam Basin are comprehensively analyzed, and four fields of tight oil exploration are predicted. The western Qaixi area has been affected by the continuous compression uplift of the Qinghai-Xizang Plateau since the Paleogene. The sedimentary environment is characterized by three distinct features: (1) the paleomorphology between the inherited paleo-slope and the concave uplift; (2) the paleoclimate with relative wetness to drought alternating frequently; (3) the lake plane and paleosalinity evolved by high frequency oscillation. Under its control, two major source rocks with large scale and high hydrocarbon generation efficiency were developed from the late Paleogene to the early Neogene, and two types of compact reservoirs, clastic rock and carbonate rock, formed a mutual source reservoir. There are three favorable types of tight oil source assemblage: source pool symbiosis and source side crossing. The evaluation and prediction results reveal that there are four types of tight oil reservoir types and exploration fields in the western Qaixi area, such as saline lake carbonate rock, shallow lake beach bar sandstone, delta front sandstone and deep lake gravity flow sandstone, and the spatial and temporal distribution is characterized by stratigraphic concentration and strong regularity. The favorable area is large, among which carbonate rock of saline lake and sandstone of shallow lake beach dam have the greatest exploration potential.
【作者单位】：中国石油杭州地质研究院;中国石油青海油田公司勘探开发研究院;
【基金】：中国石油科技重大专项(2016E-0101;2016B-0303)
【分类号】：P618.13

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