“浓缩”伽玛测井曲线用于探井地层划分、对比

Condensed Gamma Logging Curve Used for Stratigraphic Division and Correlation of Exploration Wells

该文提出一种在南图尔盖盆地已被应用,适合陆相盆地探井地层划分、对比的新形式——"浓缩"伽玛曲线。浓缩伽玛曲线是经过纵向压缩和横向放大处理的曲线,纵向上显示曲线"错断"和自然分段。自然段划分以浓缩线的趋势连续性为依据,结合其它测井信息并通过地震地层分界的验证产生。经过分析,每个自然段对应"组"地层,实际代表了与构造沉降有关的沉积旋回、A/S配置特征;分界则与地震剖面上的"地层界面"吻合,实际代表了地层超覆、地层削蚀,新一轮沉积或新的物源等信息。

A new approach, condensed gamma curve, that is appropriate for stratigraphic division and correlation of exploratory wells in continental basins is proposed in this paper, and has been applied in the southern Turgay basin. The condensed gamma curve is compressed vertically and magnified transversely to show curve dislocations and the natural segmentations. Natural segmentations are determined based on trend continuity of condensed gamma curve and other logging information, and are verified by bed boundaries on seismic profiles. Analyses reveal that each natural section corresponds to ＂group formation＂, and practically presents a sedimentary cycle related to tectonic subsidence and A/S configuration. And its boundary coincides with the stratigraphic dividing line on seismic profiles, and practically represents stratigraphic overlap, denudation, and the next deposition or change in sources.