Formulation Optimization And Performance Evaluation Of Nanoparticle Composite Slickwater Fracturing Fluid

Conventional slickwater fracturing fluids have problems such as low viscosity,poor shear stability,poor sand carrying capacity,and insufficient support for fractures,which lead to the difficulty of effective support for fractures generated after fracturing and the decrease of conductivity,thus affecting the productivity after fracturing.In order to solve this problem,a kind of nanoparticle composite slickwater fracturing fluid system was developed in this paper,and the research was carried out from the aspects of formulation optimization,performance evaluation and action mechanism of nano-materials.In this paper,solubility,drag reduction rate,surface tension and anti-swelling rate are taken as evaluation indexes to optimize and screen drag reduction agents,drainage aid agents and anti-swelling agents.Finally,a conventional slickwater fracturing fluid system with good performance is optimized.The particle size and compatibility were selected as evaluation indexes,and the dispersibility,temperature and salt resistance and stability of the nanoparticle were evaluated.Gliding water by using optimized nanoparticles with conventional fracturing fluid system for distribution,with particle size of the system,the system viscosity drag reduction rate as the evaluation index and system,optimize the adding amount of nanoparticles,finally obtained the slipperiness of nano composite water fracturing fluid system,and the slipperiness of nano composite water fracturing fluid system for performance evaluation.On the basis of the above research,combined with literature investigation and TEM methods,the drag reduction mechanism of nanoparticle composite slickwater system and the interaction mechanism between nanoparticles and drag reducers were revealed.The stability of nanoparticle composite slick-water fracturing fluid system was studied.It was found that the system had good stability,and the appearance and particle size of the system did not change significantly under the conditions of 80?and 90 days.Haake Mars60 rheometer was used to study the rheological properties of nano-composite slickwater system.It was found that the viscosity of the system could be maintained at 2.5 m Pa·s under the condition of shearing at 80?and 170s^-1 for 30min.At room temperature and 170s^-1,the viscosity of the system is not affected by the shear time,which indicates that the nanoparticle composite slickwater system has good temperature resistance and shear resistance.The friction performance of nano composite slickwater system was studied by fracturing fluid friction tester.The results show that the system has good friction performance,and the drag reduction rate is still higher than 70%under the condition of 1.8m³/h and 80?.Based on the results of dynamic sand-carrying experiments and imbibition and oil displacement experiments,it is proved that nanoparticle composite slickwater fracturing fluid system has good sand-carrying and imbibition and oil displacement ability.Core damage test results show that nanoparticle composite slickwater fracturing fluid system has the characteristics of low damage,the core damage rate is much lower than guanidine gum fracturing fluid and clean fracturing fluid.The drag reduction mechanism of nanoparticle composite slickwater fracturing fluid system conforms to the effective slip hypothesis and turbulence inhibition hypothesis.There is a cross-linking effect between nanoparticles and drag reducers,and nanoparticles also act as physical crosslinking agents,thus strengthening the network structure of drag reducers and enhancing the performance of the system.