Patent ID: 7755032
Filing Date: 2010-07-13
Classification: E21B,G01F,G01V

Abstract:
1. A method for evaluating an inflow performance for completed intervals in a well, comprising: pulsing neutrons into a fluid flow in the well; detecting gamma rays from decays of nitrogen-16 in the fluid flow with a first gamma ray sensor to generate a measurement of gamma ray decays; determining an in situ water velocity from the measurement of the gamma ray decays by: estimating the inflow performance for each of the completed intervals in the well based on a change in the in situ water velocity, wherein inflow performance of a first one of the completed intervals is determined by subtracting at least data collected relating to a second one of the completed intervals from the fluid flow; and correcting the in situ water velocity to generate a corrected in situ water velocity for a hydraulic flow area in the fluid flow, determined using an inside diameter of a flow conduit and a cross sectional area of a pulsed neutron logging tool comprising the pulsed neutron generator and the first gamma ray sensor, using following equations: wherein ν wherein d wherein area is in units of square feet and diameter is in units of inches.