河北献县东部雾迷山组碳酸盐岩热储酸化压裂试验研究

STUDY ON ACID FRACTURING TEST OF CARBONATE RESERVOIRS OF WUMISHAN FORMATION IN WESTERN XIAN COUNTY,HEBEI

通过对河北献县东部雾迷山组碳酸盐岩进行大尺寸高地应力酸化压裂物理模拟试验与小尺寸温度应力耦合环境下酸化压裂试验,讨论地应力、温度、酸液排量以及压裂模式等因素与碳酸盐岩压裂效果之间的关系,找到碳酸盐岩储层压裂裂缝的生长规律。研究表明:将裂缝发育与裂缝不发育储层碳酸盐岩压裂曲线对比发现,储层岩石裂缝发育程度可明显降低破裂压力;压裂试验中储层岩石内裂缝激活对破裂压力具有显著影响,现场压裂过程中应当考虑到储层工程地质中裂缝发育程度的问题;酸液处理可显著降低破裂压力,更有利于形成复杂裂缝网络,破裂过程中诱发更多声发射事件,同时储层岩石裂缝发育程度直接影响到压裂效果。

In this paper,the relationship between the factors of rock stress,temperature,acid discharge as well as fracturing mode and the fracturing effect of carbonate rock was discussed through the experimental test of acid fracturing with high rock stress in large size samples and the acid fracturing test under the coupled temperature-stress environment in small size carbonate rock of Wuzhishan formation in western Xian County,Hebei,China,to find the growth law of fracturing fractures in carbonate reservoir,and the main conclusions were drawn as following:Comparing the fracture development with the fracture curves of carbonate rock fracturing in the fractured reservoir,we found that the fracture development of the reservoir rock can significantly reduce the fracture pressure;Fracture activation within the reservoir rock in fracturing tests has a significant effect on the fracture pressure,and the degree of fracture development in the reservoir engineering geology should be considered in the field fracturing process;Acid treatment can significantly reduce the fracture pressure,which is more conducive to the formation of complex fracture networks and induce more acoustic emission events during fracturing;meanwhile,the degree of fracture development in reservoir rocks directly affects the fracturing effect.