高校地质学报2018，Vol.24Issue(3)：401-411,11.DOI:10.16108/j.issn1006-7493.2017110
地震反射特征对风化壳发育带的指示意义:以东营凹陷永北地区沙三上亚段为例
Investigation of Weathered Clastic Crust Based on Its Seismic Reflection Characteristics: the upper Layer of Es3in Yongbei Area of Dongying Sag
摘要
Abstract
Prediction of the developing zone of weathered clastic crust under the T1 unconformity is one of the key and critical issues in the exploration of stratigraphic reservoirs in the Yongbei area, Dongying sag. Based on integrated analyses of high-precision 3D seismic interpretation, core observation, thin section observation, logging interpretation and physical property testing, combined with the setting of structural and burial histories, we investigate the special characteristics of seismic reflection of the upper layer of the Es3 Formation under the T1 unconformity surface in Yongbei area, Dongying sag, and further address their geological implications. Results reveal a typical development of buried weathered clastic crust in the study area, which has a two-layer structure including weathered clay rocks and semi-weathered rocks. In the semi-weathered rocks, seismic event disappears to show blank reflection due to meteoric weathering and solution. This results in an improvement of reservoir properties and an interface with underlying unweathered rocks. A discontinuous angular unconformity surface was formed. In contrast, the unweathered and undissolved strata shows typical angular unconformities. The evolution of seismic reflection characteristics could be divided into 4 phases, e.g., deposition of the Es3Formation, uplifting of the Es3formation, early stage of the formation of the weathered clastic crust, and the main formation stage of the weathered clastic crust. The development of the seismic blank zone is not smaller than that of the weathered clastic crust. It changes to normal strata to the basinward. Development of weathered clastic crust improves reservoir properties largely, which could act as resrevoir space and migration path for oil and gas. Therefore, such crusts are important exploration targets of stratigraphic reservoirs in the study area for the next step.关键词
地震反射特征/风化壳/不整合/沙三上亚段/永北地区/东营凹陷Key words
seismic reflection characteristics/weathered clastic crust/unconformity/upper layer of the Es3 Formation/Yongbei area/Dongying Sag分类
天文与地球科学引用本文复制引用
王铸坤,操应长,王艳忠,李宇志,赵博,欧浩文..地震反射特征对风化壳发育带的指示意义:以东营凹陷永北地区沙三上亚段为例[J].高校地质学报,2018,24(3):401-411,11.基金项目
国家科技重大专项(2016ZX05006-007 （）
2016ZX05006-003) （）
中央高校基本科研业务费专项资金(15CX08001A)联合资助 （15CX08001A）
