S103井区玄武岩分布和厚度的确定及与低潜山成藏关系探讨

Determination of basalt distribution and thickness in S103 well-zone and discussion on relationship with low buried-hill reservoir

对S103井区测得的磁力资料向上延拓一定高度,并求取垂向二阶导数,获得反映中等深度的房身泡组玄武岩的磁异常。根据剩余磁异常分布及磁异常零值线划分高(正)磁异常与低(负)磁异常边界,高磁异常区在本区可视为玄武岩磁性体大致分布范围,玄武岩缺失区为负磁异常范围,据此勾绘出两处玄武岩缺失区。用二度半体人机联作方法对磁异常剖面进行计算,结合工区钻井资料及磁性参数测定,求取每条剖面的玄武岩厚度,并勾绘视厚度图。勘探实践表明,房身泡组玄武岩的分布与厚度直接影响低潜山的成藏,笔者讨论了本区火山岩分布与低潜山成藏的关系。

The magnetic data surveyed in S103 well zone are upward continued to certain height and vertical second derivative to the data is carried out, which results in magnetic anomaly trap reflecting Fangshenpao Formation basalt with middle depth. The boundary between high (positive) magnetic and low (negative) magnetic anomaly is divided according to distribution of residual magnetic anomaly and zero-line of magnetic anomaly, the high magnetic anomaly zone in the areas can be viewed as general distribution range of magnetic basalt bodies and basalt-absent zones are ranges of negative magnetic anomaly, based on which the two basalt-absent zones are drawn. The 2.5D man-computer interaction approach is used to computer magnetic anomaly section and apparent isopach map is drown. The exploration practice showed that the distribution and thickness of Fangshenpao Formation basalt directly affect the reservoir of low buried-hill, and the authors discussed the relationship between the distribution of basalt and low buried-hill reservoir.