在所能实施CO2地质封存的场所中,含水层的封存潜力最大。而在影响封存量的各种机理中,地层构造封存是最基本的机制。本文提出了一种测定影响地层构造封存量的关键参数———残余水饱和度的实验方法,并将该方法实际应用于富含油气资源的塔里木盆地奥陶系礁灰岩。首先根据饱和称重法和渗透实验测得样品有效孔隙度和渗透系数分别为0.0283,5.56×10-9m/s。残余水饱和度的值是在40℃,8Mpa条件下,通过超临界CO2驱替饱水岩心实验得到,测定结果为0.451。同时,还得到了超临界CO2驱替饱水岩心压力、流量变化特性。
Saline aquifer has the most sequestration potential among all the sites that can implement CO2geological sequestration.Structual stratigraphic sequestration is the basic mechanism which can affect CO2storage capacity in a saline aquifer.In this paper,an experimental method is used to measure the irreducible water saturation to a rock sample,a key parameter that affects structual stratigraphic storage capacity.The rock sample is taken from the Ordovician reef limestone in the Tarim Basin,which is widely considered to be rich in oil and gas,Firstly,effective porosity and permeability coefficient of the sample are measured with saturated weighing and permeating experiment,and are 0.0283,5.56×10-9 m/s,respectively.Irreducible water saturation is measured through supercritical CO2flooding core saturated water under simulating strata temperature of 40℃ and strata pressure of 8 MPa,and the result is 0.451.Meanwhile,the changes in pressure and flux with time are observed during the core flooding experiment through supercritical CO2.