Interpretation of Array Production Logging Measurements in Horizontal Wells for Flow Profile
Interpretation of production logging in multi-phase flow wells is challenging, especially for highly deviated wells or horizontal wells. Flow regime-dependent flow conditions strongly affect the measurements of production logging tools. Segregation and possible back flow of denser phases result in misinterpretation of the inflow distribution. To assess the downhole flow conditions more accurately, logging tools have been developed to overcome the flow regime related issues. Multiple-sensor array tools measure the fluid properties at multiple locations around the cross-sectional area of the wellbore, providing a distributed measurement array that helps to relate the measurements to flow regime and translate the measurement to inflow distribution. This thesis present a methodology for using array data from production logging tools to interpret downhole flow conditions. The study uses an example logging tool that consists of 12 resistivity, 12 capacitance probes, and six spinners around the wellbore circumference. The method allows interpretation of phase volumetric flow rates in sub-divided cross-sectional areas based on sensor locations. The sub-divided area method divides the wellbore cross-sectional area into several layers depending on the number and arrangement of the sensors with each layer containing at least one sensor. Holdup and velocity outputs from sensors in each wellbore area segment are combined to calculate the volumetric flow rates of each phase in each segment. These results yield a profile of flow of each phase from the high side to the low side of the wellbore, and the overall flow rates of each phase at every location along the well where the interpretation method is applied.
The results from different methods of interpreting production logging are compared in the thesis. Three Eagle Ford horizontal well examples are presented in the thesis; one has single sensor PLT measures, and the other two cases used a multiple sensor tool package. The examples illustrate differences of interpretation results by different methods, and recommend the procedures that yield better interpretation of multiple sensor array tools.