The Effect Of Temperature On The Phase Infiltration Curve Of LN Oilfield

With the intensive development of exploration on oil/gas reservoirs, an increasing number of reservoirs with high temperature and pressure have been found. Relative permeability curve is an important tool to describe the fluid flow capacity during the process of multiphase percolation, which has significant importance to guide the development of oil/gas reservoirs efficiently. Since it is too complex to obtain the permeability curve under high temperature/pressure conditions, most core displacement experiments are conducted at 50? in laboratory, which fails to reflect the percolation characteristics under reservoir condition. Though many studies have been carried out on the effects of temperature on permeability curves, no common conclusion has been drawn on its influence pattern and mechanism. Thus, it is of great importance to research the temperature influence pattern on permeability curves both theoretically and practically.Taking cores drilled from LN oil reservoir with different levels of porosity and permeability as samples, a set of complete experiment program and procedure of high pressure and temperature displacement has been designed, which is measured by the independently-developed advanced machine. On basis of these experiments, the data processing method has been improved according to practical displacement conditions with the initiative idea of "integrated interpolation processing method of relative permeability data" and "a novel algorithm of power law water cut analysis method". Furthermore, an unsteady state relative permeability data processing package was developed based on MATLAB software platform, which satisfied to make concrete analysis with specific displacement conditions. And on this basis the effects of temperature on oil-water relative permeability curve for LN oilfield were analyzed according to nuclear magnetic resonance techniques, scanning microscope techniques and X-ray scattering techniques comprehensively. The research shows that the effects of increasing temperature on relative permeability curves present basically the same pattern in the whole region, which makes oil and water permeability higher with same water saturation, crossover saturation point shift righter and the system become more water-wet. However, due to rock physical property differences, the degree of temperature impacts on cores with different permeability levels varies from each other. Because of the remarkable influence of temperature, a new method to predict the relative permeability curves under reservoir condition was proposed utilizing JBN formula and empirical formulas according to relative permeability data measured in normal laboratory condition. Comparing to oil field example, curves obtained from this new method have an excellent match with measured data, providing a valuable reference for laboratory tests of permeability curves in high temperature reservoirs more conveniently and practically, with litter error cased.