碳酸盐岩储层孔隙胶结指数m变化规律及理论研究

Theoretical Research on Variable Laws of Pore Cementation Exponent m of Carbonate Reservoir

通过分析塔中地区奥陶系大量碳酸盐岩岩电实验发现:塔中奥陶系碳酸盐岩孔隙胶结指数m值随孔隙度的增大而增大,且这种增大的趋势随着孔隙度的增大而逐渐变缓。结合岩电实验,从理论上研究了这一现象,并研究碳酸盐岩孔隙结构参数对m值的影响规律:m值的大小与岩样中孔洞形状有关,沿电流方向的孔洞长轴越长,m值越小;裂缝有效宽度越宽、喉道直径越大,m值越小;孔隙度相同的情况下,由裂缝沟通的孔洞较孔喉沟通的孔洞m值要小。

By analyzing great number of core-electricity experiments on Ordovician carbonate in Tazhong Area, it was found out that the pore cementation exponent m of Tazhong Ordovician carbonate raised with the increase of porosity, its increase trend reduced with the increase of porosity.In combination with the core-electricity experiment.The phenomenon is studied theoretically.Also the influencial laws of its pore structural parameter on m value are studied, the size of m value is related with cave shape, the longer the cave axis along the current direction is, the less the m value is, the wider the fracture is, the bigger the pore throat diameter is , the less the m value will be.Under the condition of same porosity, for the cave communicated by fracture, its m value is less than that of throat connected one.