辽河盆地清水地区泥岩欠压实与油气层分布

UNDER-COMPACTION OF MUD ROCK VERSUS DISTRIBUTION OF OIL AND GAS RESERVOIRS IN QINGSHUI AREA OF WESTERN DEPRESSION OF LIAOHE BASIN

储集层有利分布区的预测是油气勘探的一个重要研究领域 ,在实际工作中往往采用一些常规的方法进行研究 ,如从沉积学、储层地质学着手 ,并结合物探、测井资料对储集层进行纵、横向预测。但随之而产生的问题是研究周期较长 ,投资较大 ,因此寻找一种简捷的方法来进行预测 ,一直成为人们探索研究的重点。通过对辽河盆地西部凹陷清水地区沙河街组的研究发现 ,在泥岩欠压实段内的砂岩层往往就是有利的储层 ,并且油气层多分布于欠压实段内。由此给人们以启示 ,可以利用泥岩欠压实特征来对有效储层的分布区进行预测。最终研究表明 ,泥岩欠压实与储集层的形成、油气运移及油气层分布在机理上存在着密切的关系 ,利用泥岩欠压实曲线 ,可以预测有效储层的纵横向分布 ,结合其它因素综合分析 。

The prediction on distribution area of favorable reservoirs is an important research field in petroleum exploration. In practice, some routine methods have been taken to conduct research. For example, sedimentology and reservoir geology, in combination with seismic and well log information, have been used to predict the reservoir horizontally and vertically. However, the problem resulted is long period of research and huge investment. Therefore, a convenient method for predicting reservoir has being probed. After the observation on Shahejie formation, Qingshui area of western depression of Liaohe basin, it is found that the sandstone in the intervals of under-compacted mud rock might be favorable reservoirs and the oil and gas reservoirs are mainly distributed in the intervals of under-compacted mud rock. Therefore, the characteristics of under-compacted mud rock could be used to predict the distribution area of favorable reservoirs. It is finally shown that under-compaction of mud rock is closely related to the formation of reservoir, petroleum migration and the distribution of oil and gas reservoirs in mechanism. By using the curve of under-compacted mud rock, the horizontal and vertical distribution of favorable reservoir could be predicted. Combined with the comprehensive analysis on other factors, the oil and gas reservoirs as well as their distribution area might be recognized.