高邮凹陷阜四段页岩可压裂性分析

利用X衍射和岩石三轴定向力学技术,获取了高邮凹陷阜四段(E1f4)页岩的矿物组成、杨氏模量、泊松比及脆性系数等参数,分析了页岩的可压裂性。认为高邮凹陷E1f4页岩脆性矿物含量高(平均大于50.72%),泊松比适中(0.19~0.26),脆性指数较高(30.10%~44.71%),与中国东部泌阳凹陷核三上、东营凹陷沙三下页岩一样,具有较好的可压裂性。但页岩杨氏模量相对较低(12.9~19.4 GPa),可压裂性略差于中国南方海相龙马溪页岩和美国Barnett页岩;且页岩粘土矿物含量较高,组成以伊/蒙混层矿物为主,遇水易膨胀。综合评价E页11f页34可压裂性最好,E1f页24和E1f4次之,E1f页44最差。

Analysis on fracability of E1 f4 shale in Gaoyou sag

By using X-ray diffraction technique and rock mechanical triaxial directional test ,the parameters such as mineral composition,Young’s modulus,Poisson’s ratio and brittleness indexes are obtained ,and the fracability of E1f4 shale is analyzed in this paper .The results show that the brittleness mineral content of E 1 f4 shale is high ,with an average value greater than 50.72%.Poisson’s ratio is moderate,between 0.19 and 0.19.Brittleness index is higher ,between 30. 10% and 44.71%.The E1f4 shale in Gaoyou sag,as well as the E1h3upper shale in Biyang sag and the E 1s3lower shale in Dongying sag,has good fracabilities.In view of the lower Young’s modulus （between 12.9 GPa and 19.4 GPa）,and the higher content of clay minerals,the fracability of E1f4 is slightly less than S1l shale in South China and Barnett shale in USA.The clay minerals of E1f4 shale are predominantly montmorillonite and mixed -layer illite/smectite.The E1f4 shale is easy swelling in water .Comprehensive evaluation showed that the fracability of E 1 f4 shale3 is the best,better for E1 f4 shale2 and E1 f4 shale1 ,and the worst for E 1 f4 shale4 .