交联聚合物在岩心孔隙中长期滞留性能研究——以双河油田Eh3Ⅳ5-11岩心为例

Study on long term retention of crosslinked polymer in core pores——by taking the core from Eh3Ⅳ5-11 of Shuanghe oilfield as an example

为进一步认识交联聚合物在岩心孔隙中长期滞留的性能变化及对储层孔渗伤害的程度,采用双河油田核三段Ⅳ油组5-11层系天然岩心进行室内实验。通过CT扫描,研究了不同渗透率岩心进行交联聚合物驱后孔隙度、渗透率的变化情况。结果表明,天然岩心在注交联聚合物结束后,岩心孔隙和喉道中充满交联聚合物,岩心孔渗降低幅度较大;在地层条件下静置12个月后,交联聚合物在岩心中会产生降解,岩心孔、渗可以恢复,其中,高、中渗岩心孔渗恢复最好,恢复率均在90%以上,但低渗岩心恢复程度较差。实验结果进一步明确了交联聚合物适宜的油藏条件,为矿场调剖提供了依据。

In order to further understand the long-term retention performance of crosslinked polymer in core pores and the influence on reservoir porosity and permeability damage, laboratory experiments were conducted on Ⅳ5-11 natural cores in Shuanghe oilfield. The change of porosity and permeability of different permeability cores after crosslinked polymer flooding was studied by means of CT scanning method. The results show core porosity and throat are full of crosslinked polymer after the injection of crosslinked polymer, and the core porosity and permeability decrease greatly. After standing for 12 months under the formation conditions, the crosslinked polymer will degrade, and the porosity and permeability can be recovered. The porosity and permeability in high-medium permeability cores are the best, and the recovery rate is above 90%, but the recovery degree in low permeability cores is poor. The experimental results further clarify the suitable reservoir conditions, and provide the basis for field profile control.