Synthesis and performance evaluation of a hybrid cross-linked plugging agent

Key words:  gel plugging agent  hybrid cross-linking  synthesis mechanism  rheological properties  plugging performance

Abstract:

In terms of the poor high temperature resistance and mechanical properties of conventional chemical gel plugging agent, a hybrid cross-linked composite gel material was synthesized. In the gelpreparation the γ-methacryloxypropyltrimethoxysilane (MPTMS) was the silicon source, the Laponite was the toughening agent and inorganic crosslinking agent, a self-synthesized reactive micro-gel BWL was used as the organic crosslinking agent, acrylamide (AM) and methacrylic acid (MAA) were selected as the monomers. Several physical properties of the gel were investigated, such as the viscoelasticity, the reinforced temperature resistance of SiO₂, and the reinforced mechanical properties of Laponite. The results show that, the hybrid cross-linked composite gel has a triple cross-linked network structure compared with conventional gels, which can maintain a high storage modulus and loss modulus, good tensile and compression resistance after aging at 140 ℃. When the 2% gel particles with the size of 0.25-0.38 mm, 0.38-0.83 mm and 0.83-1.70 mm, it meets the pressure-bearing plugging needs for high permeable and fractured formations with drilling fluid lost circulation.