Research on phase flow rate measurement method for the oil and water stratified flow in horizontal wells

In low flow rate horizontal wells, the main flow pattern of oil-water two-phase flow is stratified flow. The local velocity and local phase holdup along the radial direction of pipe are complicated, and because of the gravity differentiation, the distribution of fluid velocity field changes along gravity direction. Therefore, it is very difficult to measure the mixture flow and water holdup, and interpret each phase flow in production logging. In this research, oil-water two-phase flow dynamic experiments were conducted in horizontal simulation well by using combination production logging tool including the min-spinner and the mini-capacitance prober working at five vertical positions. At the same time, numerical simulations in the same fluid properties and flow structure were carried out. The response characteristics of the spinner flowmeter and the capacitive sensor at five measured positions were studied with a well inclination angle of 0° and different flow rates and water cuts. According to the response characteristics of the spinner flowmeter and capacitive sensor in different range of total flow and water cut, the capacitance water holdup interpolation imaging algorithm was used to calculate the height of the oil layer and he flow measurement values were combined with the numerical simulation of the oil-water two-phase N-S equation to establish an optimal calculation model for obtaining the velocity field distribution and the flow profile. Compared with the experimental results, each phase flow rate measurement result of oil-water two-phase stratified flow has high precision.