Research of a retarding crosslink weak gel for conformance control and displacement and its performance evaluation

Due to the short gelation time of the present cross-linked polymer gel system, conformance control agent cannot enter into deep reservoir, resulting in poor water flooding effect. By the crosslinking reaction between the retarding organic composite cross-linking agent NQJ and salt-resistance polymer under thermal stabilizers and specific temperature, the weak gel with space network structure is formed. The weak gel conformance control agent has low surface viscosity, easy injection on-site, and good delayed cross-linking effect, so it can achieve the high-dose injection. The research shows that the mass fraction of salt-resistance polymer, cross-linking agent, and the heat stabilizer are 0.15%-0.25%, 0.15%-0.2%, and 0.015%-0.025% respectively. The viscosity of gel is greater than 5000 mPa·s, and the gelation time is 3~6 days. The weak gel can meet the need of deep reservoir conformance control and oil displacement, and improve the water flooding effect of high water cut oil field.