苏仁诺尔断裂带含片钠铝石砂岩储层物性特征及成因

CO2是一种可溶于水进而形成酸性流体的"活性气体".在酸性流体条件下,一些矿物发生溶解,而另一些矿物发生沉淀,使砂岩的孔渗发生改变.苏仁诺尔断裂带CO2流体在与砂岩相互作用过程中,形成了片钠铝石和铁白石的自生矿物组合,导致研究区含片钠铝石砂岩储层物性变差.分析CO2流体与砂岩的相互作用发现,片钠铝石含量较高是储层物性变差的直接原因,而片钠铝石生长时间晚于其它自生矿物且在充填孔隙后没有发生溶蚀是储层物性变差的根本原因.

Reservoir characteristics and origin of dawsonite-bearing sandstones in Surennuoer Faulted Zone

CO2 is a kind of active gas that can be dissolved into water to form acid fluid. Under acid fluids environment, some minerals will be dissolved and some other minerals are deposited, so, the porosity and permeability of the sandstone will change. In Surennuoer faulted zone, the authigenic mineral assemblage of dawsonite and ankerite are formed during the mutual action between CO2 fluids and sandstone, and then the reservoir properties of dawsonite-bearing sandstone becomes poorer. Based on the analysis of the mutual action between CO2 fluids and sandstone, it is found that the higher content of dawsonite is the main cause for poorer reservoir properties, and the dawsonite is formed later than other authigenic minerals and no erosion oceurres after the pores filling, which are the basic factors resulting in poor reservoir properties.