Measurement of Relative Permeability Curves of Cores with Different Permeability and Lengths under Unsteady-State

Abstract

The oil-water and gas-water relative permeability curves are important reference data for the dynamic analysis and numerical simulation of oil and gas reservoir exploitation. Although the petroleum industry of China and other countries have formulated reference standards for the measuring methods of relative permeability of cores, they haven’t given the definite reference values of the core length, therefore we cannot know for sure whether different core length values are required in the measurement and whether the core length has an impact on the measurement results. In view of this gap, this paper conducted a research on the relative permeability of cores with different lengths. The core samples are artificial core with similar properties as the outcrop cores of the Halfaya Oilfield (Iraq), in our experiment, the oil-water and gas-water relative permeability curves of the sample cores were measured and the results suggest that, for the oil-water relative permeability curves, as the core length grows, the iso-permeability points move to the right, and they basically stabilize when the core length is greater than 20cm; as for gas-water relative permeability curves, in case of low-permeability cores, under constant injection pressure, as the core length grows, the iso-permeability points and the two-phase co-permeation areas present an obvious tendency of moving to the left, but when the core length is greater than 20cm, such tendency is not obvious, and the high-permeability cores do not have such characteristics. These results indicate that, the unsteady-state two-phase relative permeability measurement experiments obtained accurate results at a core length of about 20cm, which provided a reference for similar experiments in subsequent research.

Hydrodynamics of Reservoirs in Arid Areas and Its Influencing Factors

“…Since the simulation and calculation of the hydrodynamics of the target reservoir must deal with irregular boundaries and complex terrains, this paper built a 2D hydrodynamic model using unstructured triangular grids, in which any triangular is taken as the unit of calculation. A finite-volume unit center method was adopted to solve the equations, and the established 2D hydrodynamic model was used to calculate the hydrodynamics of the target reservoir [13][14][15][16][17] and analyze the hydrodynamic process under different influencing factors, thereby providing theoretical evidences for the management of water environment and the improvement of water quality of the Yazidang Reservoir.…”