Modeling and Experimental Study of Self-Suspension Fracking Liquid Containing Nanoparticles

Self-suspension systems for fracturing technology has proved to provide great convenience when used in oilfield operation. However, most fracturing fluid systems contain mainly cationic surfactants, which can easily cause reservoir damage, solution residue, and poor temperature resistance. In the case of the cationic-surfactant fracturing system, the fluid sand carrying capacity is not high enough to change the formation pressure, and the failure of the self-suspension ability leads to a decline in well production capacity and other problems. In this paper, we have proposed an architecture model of a self-suspension solution containing nano-particles, including the model of nano-particle monolayer adsorption on the proppant surface and the three-dimensional network-structure model of nano-particle adsorption on micelles in the solution. The rheological properties, temperature resistance, viscoelasdcity, sand-suspending capacity, gel-breaking properties, and core damage of the modified solution are tested and evaluated. The viscosity and temperature resistance, enhanced sand suspension, and sand-carrying capacity are verified by field application experiments. The results show that the modified fluid system has obvious advantages over traditional fracturing fluid systems and can eliminate the shortcomings of conventional fracturing. The proposed nanoparticle self-suspension solution technology helps to overcome construction difficulties and to reduce engineering costs and environmental pollution, as well as to increase production of the oil wells. The experimental validation results prove that the proposed fluid system can be successfully applied in complex oilfield formations.