松辽盆地F油层高岭石、伊利石对储层物性、敏感性影响的实验研究

松辽盆地F油层砂泥岩互层发育，高岭石、伊利石为其主要粘土矿物，对研究储层物性及该油层的有效开发具有重要意义。本文通过对F油层90块天然岩心的室内研究发现，F油层渗透率、孔隙度随着高岭石相对含量的增加而增加，随着伊利石相对含量的增加而减小。砂岩层渗透性较好，高岭石相对含量较高，次生石英很少就地沉积，大量长石溶蚀孔隙得以保存；泥岩层渗透性差，伊利石相对含量较高。而且伊利石纤维状赋存和高岭石书页状赋存使砂岩层孔渗性更好，而使泥岩层孔渗性更差。该层开发过程中，高岭石、伊利石对储层物性的影响由室内岩心流动实验可知，F油层为中等强度偏弱速敏、中等强度偏强碱敏，速敏指数随着高岭石、伊利石绝对含量的增加而增加；储层的碱敏指数随高岭石绝对含量的增加而增加，而与伊利石含量无关。由于在所有粘土矿物中，高岭石相对含量接近一半，所以在F油层的开发过程要注重防范高岭石的碱敏、速敏损害。

Effects of kaolinite and illite on physical property and sensitivity damage in the F reservoir of the Songliao Basin

Interbedded sand-mud stones are developed widely in the F reservoir of the Songliao Basin, and kaolinite and illite are main clay minerals in the F reservoir, which are very important for the physical property and the effective development of the reservoir. The study of the 90 pieces of natural cores shows that both permeability and porosity of the F reservoir increase with the increase of kaolinite relative content and decrease with the increase of illite relative content. Sand-stone layer has good permeability and high kaolinite relative content, and in this layer secondary illite seldom deposits in-situ, resulting in the existence of large amounts of erosion pores. In contrast, the mud-shone layer has poor permeability and high relative content of illite. Moreover, the fiber-style existence of illite and book-stack-style existence of kaolinite make the sand-stone permeability much better and the mud-stone permeability much worse. The effect of kaolinite and illite on the reservoir physical properties can be detected by in-house core flow experiments. The results show that the F reservoir has a medium but slightly weak velocity sensitivity and a medium but slightly strong alkaline sensitivity, and that the velocity sensitivity of the reservoir will increase with the increase of kaolinite and illite absolute content, and the alkali sensitivity will increase with the increase of kaolinite absolute content but has no relationship with the illite content. More attention should be paid to the kaolinite-oriented velocity and alkaline sensitivity, for the relative content of kaolinite approximates half of all clay content in this reservoir.