多夹层盐穴储库沉渣碎胀-膨胀系数试验研究

Experimental Investigation on Bulking-expansion coefficient of Sediment of Storage in Bedded Salt

夹层垮塌后破碎岩石的碎胀-膨胀系数是多夹层盐岩地下储气库体积预测计算中的关键参数。通过理想试验以及逻辑分析,研究了碎散体的形状、大小、排列方式以及颗粒级配对夹层碎胀系数的影响。结果发现,碎散体的大小与碎胀系数无关;碎散体的表面积体积比越大,碎散系数越小,反之越大;边-边接触越多碎胀系数越小,边-角接触越多碎胀系数越大;颗粒级配越不均匀越不连续碎胀系数越大,反之越小。通过模拟夹层垮塌,得出垮塌后的碎散体级配不良,分配集中,碎胀系数较大。碎胀系数随颗粒级配的范围扩大而降低,全范围颗粒级配的碎胀系数为1.701,且卤水浸泡对碎散体体积没有明显影响。根据参数计算得出的预测体积和声纳测腔结果符合良好,表明试验获取的碎胀系数具有工程实用性。

Bulking -- expansion coefficient （BEC） of broken rocks after interlayer collapse is a key parameter in the vol- ume prediction of UGS （Underground Gas Storage）. Idea ex- perinaents and logical analysis have been carried out to study the impact of shape, size, arrange style and grain composition of broken rock to BEC. The results indicate：BEC has nothing with the size, and the bigger surface density is, the smaller the BEC is;the more face--to--face contacts, the bigger the BEC,while the more face-- to- point contacts, the smaller the BEC;the more inhomogeneous the grain composition, the bigger the BEC. Bad gradation and distribution concentration were showed in the simulation of interlayer collapse, so the bulking coefficient of broken rock is bigger relatively. Bul- king coefficient becomes smaller when the range of grain composition goes bigger. The bulking coefficient of whole range grain composition is 1. 701, and brine immersion has no obvious effect to the volume of broken rocks. Predicted volume calculated by BEC, which got in laboratory, fit well with the volume surveyed by sonar, so the BEC obtained in laboratory is practical.