Experimental Research Of Cuttings Particle Size On Wellbore Circulation Of Supercritical Carbon Dioxide

In recent years,with the continuous progress of gas drilling technology,supercritical carbon dioxide as a new type of drilling fluid,in the development of unconventional oil and gas resources show a huge advantage,low viscosity and high diffusion coefficients of supercritical CO₂ drilling fluid with gas,high density and has the characteristics of liquid solubility,can to meet the requirements of continuous tube drilling,but the development of this technology is still in its infancy.Supercritical carbon dioxide fluid pressure and temperature gradually increases with the increase of depth,but the density and viscosity with well depth decreased,analysis of supercritical carbon dioxide in the process of drilling,and the water system and the interaction of cuttings,the average particle size and reaction temperature,carbon dioxide changes system of cuttings the average particle size and reaction pressure variation of cuttings particle size,has important value for the study of supercritical carbon dioxide with rock and promote the development of the supercritical CO₂ drilling technology.In this paper,first through the analysis of the experimental method of carbon dioxide and conditions coexist with different fluid under the influence of drilling cuttings diameter,and the mechanism was studied by methods of XRD ion and the results showed that the average particle of carbon dioxide and water co-exist can effectively reduce the size of the Guantao formation drilling its mechanism is due to carbon dioxide,the dispersion of clay minerals in cuttings,shortening the clay mineral hydration reaction time,carbonate and carbon dioxide and water will produce a certain amount,will dissolve parts of mineral cement,the cuttings particle size becomes smaller,the results provide a basis for further explanation of the articles the mechanism of rock.