东营凹陷碳酸盐岩白云石化储层孔隙形成机理研究

Effects of Dolomitization in Carbonate Rocks on Reservoir Porosity in the Dongying Depression

以东营凹陷碳酸盐岩样品分析为基础,研究了工作区内碳酸盐岩白云石化对储层孔隙度的影响机理。结果表明,白云石化作用后碳酸盐岩储层粒间孔增加或保持不变,形成了颗粒内晶间孔和晶间微孔,增大颗粒的比表面积;反映出白云岩比灰岩更具有抵抗压溶的能力,相对较强的抗压实能力减少了压溶作用;微孔和粒间孔的存在,为后续的具有侵蚀性的酸性流体的导入提供了条件,导致砂屑和鲕粒的溶蚀,形成粒间溶孔、粒内溶孔,促进了溶蚀孔隙的形成。白云石化作用对碳酸盐岩储层物性具有重要影响。

The paper studied the effects of dolomitization in carbonates to the porosity of reseveiors in the Dongying depressing by analyzing the carbonate samples.The results showed that the number of the inter-granular pores increases or keep same,and that intercrystalline pores and intracrystalline micropores are formed to increase the specific surface area.Dolomite has a better ability to resist the pressed solution due to the better ability to resist pressure.The existing of micropores and intergranular pores promotes the transportation of subsequent acidic fluids to form intraclastic graistones and oolite and eventually to form dissolution pores.Therefore,dolomitization has important influences on the properties of carbonate reservoir.