三肇凹陷青山口组-段泥岩超压形成与演化过程初探

在泥岩超压形成与演化机制研究的基础上，利用声波时差资料，根据泥岩破裂与愈合机理建立了-套泥岩超压形成与演化过程的恢复方法，并对松辽盆地三肇凹陷青山口组一段泥岩中的超压形成与演化过程进行了恢复.青一段泥岩沉积初期开始形成超压之后，先后经历了5次释放，目前正进入第6次超压演化过程中.因其超压自身释放时期相对较早（均早于源岩大量生烃期），对内部油气排出不起作用，后期稳定发育，对下伏扶杨油层的油气聚集与保存十分有利，这可能是造成该凹陷扶杨油层油气聚集的一个重要原因.该实例充分表明本文的方法用于泥岩超压形成与演化过程恢复是可行的.

A discussion on formation and evolution process of overpressure in mudstone of Member 1,Qingshankou Formation in the Sanzhao Sag

Based on the study of formation and evolution mechanism of overpressure in mudstone and cracking and sealing mechanism of mudstone, a method recovering formation and evolution process by interval transit time was set up.Formation and evolution process of overpressure in the mudstone of Member 1, Qingshankou Formaton in the Sanzhao Sag of Songliao Basin was recovered by the method.The overpressure in the mudstone once released 5 times since its formation in the early sedimentary preriod of the member, and now it is carrying on its sixth cycle.The release period of overpressure of the mudstone was earlier than the period of oil-gas generation of source rocks,so the release of overpressure did not play a role in the oil-gas discharge.But it was favorabe for accumulation and preservation of oil and gas from the underlying Fuyu-Yangdachengzi oil layer, which should be an important cause for creation of the Fuyu-Yang-dachengzi oil layer in the Sanzhao Sag.The example indicated the method being practical to recover formation and evolution process of overpressure in mudstone.