四川盆地三叠系隐伏钾盐层识别与预测方法研究

本文首先通过总结四川盆地钾盐(杂卤石、富钾卤水)的测井响应特征,提出钾盐的测井组合识别法;其次为满足大数据量预测处理需求,介绍了钾盐的测井旋回地层学预测法,该方法具有处理速度快,预测准确度高的特点;最后在实际资料处理与解释中,本文采用了测井旋回地层学法初步预测潜在含钾层段,测井组合识别法再对存疑含钾层段精细排查的技术组合策略,对四川盆地三叠系钾盐资源分布进行了预测,并根据预测结果,划分了4期咸化旋回,指明了3个成钾期,圈定了4个成钾有利区。

Research on identification and prediction method ofthe Triassic potash deposits in Sichuan basin

The potassium formation (i.e. polyhalite formation and potassium rich brine formation) in Sichuan basin is difficult to be identified by geophysical methods because of its characteristics of deep burial and thin interbed. In this paper, we firstly summarized Sichuan potassium well logging response and proposed well logging curve overlapping method to identify potassium formation. Secondly, we analyzed difficulties of seismic recognition techniques and presented well logging constraint inversion to detect potassium formation. Thirdly, we put forward well logging cyclostratigraphy method to locate potassium formation and used it to predict the distribution of Sichuan potassium formation. Finally, we got isopach maps of potassium formation in three different potash forming periods and developed geological understanding to Sichuan potash depocenter shift.