Preparation of a functional fracturing fluid with temperature- and salt-resistance, and low damage using a double crosslinking network
Yang Zhang, An Chen, Jincheng Mao, Songhai Qin, Jin Li, Xiaojiang Yang, Chong Lin, Zhiyu Huang, Yafei Liu
Abstract
Fracturing fluids (FFs) have been widely used to stimulate the tight reservoir. However, current FFs will not only lose their rheological property at high temperatures and high salt but also show an incomplete gel-breaking property. Herein, a double crosslinking network FF with pretty superiorities in rheology and low damage to the core was constructed by introducing both physical crosslinking and chemical crosslinking into the system. The construction of double crosslinking networks enhanced the rheology of this functional FF. The particle sizes of gel-breaking fluids are mainly distributed in 1.0–10,000 nm; furthermore, for every 10,000 mg/L increase in salinity, the particle size of the gel-breaking fluid is decreased by almost half. The adsorption capacity (<1.0 mg/g) gradually decreased with the increase of salinity at 20 °C. Moreover, the adsorption of gel-breaking fluids on the rock decreased first and then kept stable with temperature increasing at a salinity of ≤30,000 mg/L, however, showed the opposite trend at 40,000 mg/L. The results of rheology, particle size, static adsorption, and core damage showed that this functional FF could be an alternative for the stimulation of a tight reservoir with high temperature and recycling of produced water with high salinity.