岩层阻水性能及自然导升高度研究

在沉积、成岩或者构造运动过程中,由于含水层内超压流体引起围岩爆裂导致流体在弱渗透层或者隔水层中导升,形成含水层的自然导升带。影响岩层阻水性能以及导升高度的因素有:构造、地应力、岩层渗透性和力学特性及其物理化学性质、水压力等。实验表明:初始水头压力越大,水头衰减速率就越大;水头压力损耗随着介质的渗透系数增大而减小。实际观测表明:泥岩、粉砂岩、中砂岩、灰岩的阻水性能由大到小,而导升高度则由小变大。通过实验和实际观测总结出流体3种导升机制:局部关键层整体破断裂缝、欠压实带中的壳破裂裂缝和水力压裂裂缝。

Rocks' water-resistance ability and natural progressive intrusion height

In the process of sediment,rocks formation and tectonic movement,progressive intrusion zones were formed because of surrounding rocks fracturing by over-pressure liquid inside aquifers and progressive intrusion of artesian water into protective aquiclude.There are several influence factors of ability of water-resistance and progressive intrusion height: tectonics,geo-stresses,rock permeability and mechanical,physical,chemical characteristics,water pressure. Test results show that the larger initial water pressure,the larger decay rate of water head;The rule of water pressure losses is decreasing with media permeability coefficient increasing.The tests in-situ indicate that ability of water-resistance of mudstone,silt stones,middle-grained sandstones, limestones varies from large to small,but progressive intrusion height is from small to large.Three mechanisms of progressive intrusion can be summed up,including cracks by local key layers fractured,cracks by crustal fractured in poor-consolidated zones,and cracks by hydraulic fractured.