Study On Two-Dimensional Nano-Material Composite Of High Viscous Slick Water

Slick water fracturing fluid has the advantages of high drag reduction and low cost,and has gradually become one of the key working fluids for unconventional volume fracturing operations.It plays a vital role in the development of tight/shale oil and gas at home and abroad.At present,the slick water occupies the highest market share in the field of fracturing fluid.However,slick water also has disadvantages such as insufficient sand-carrying ability,poor temperature and salt resistance,which will inevitably limit the further promotion of slick water,especially with the increase of exploration depth and formation heterogeneity.Nanotechnology shines brightly in many industries.Using the physical and chemical properties of the structural units of nanomaterials in the nanometer range to develop functionalized composite materials in the field of materials has always been a hot spot for researchers.2D nanomaterials have excellent surface and interfacial energies and abundant defect sites,and it has been reported that combining with traditional fluid materials can greatly improve the rheological properties.Therefore,the thesis starts from the synthesis of 2D nanometers:1T-Mo S2 nanosheets and graphene oxide（GO）with hydrothermal method and improved Hummers method,respectively.Then using Raman spectroscopy,X-ray photoelectron spectroscopy,atomic force microscopy,etc to characterize the materials.After compounding two-dimensional nanomaterials with viscous slick water,explore the viscosity and modulus changes of nano slick water,and optimizing the viscosity-enhancing formula.The parameters such as reduction resistance properties,sand-carrying properties,temperature and salt resistance,and gel-breaking fluid properties are investigated.And the microscopic mechanism of nanomaterials viscous slick water is discussed by means of thermogravimetric analysis,low-field nuclear magnetic resonance,and environmental scanning electron microscopy.The results show that the apparent viscosity and the viscosity-increasing efficiency of TS-8 can reach 43 m Pa·s and 175%,the static sand-carrying capacity can be increased by 87%,and the drag reduction rate can exceed 60%,while the temperature and salt resistance are enhanced,and the spontaneous imbibition recovery of 33%crude oil can be achieved due to Marangoni effect.On the other hand,the coordination bond in Mo S₂ is cross-linked with slick water,the viscosity increases,but the elastic modulus decreased.The purpose of this thesis is to use 2D nanomaterials to improve the pain points of slickwater fracturing fluid in the operation process,which contributes to endow slickwater with new application scenarios,and to provide new research ideas and methods for the application of nanomaterials in the field of oilfield development.