Temperature pulsed injectivity profiling

Claim 1

A process for measuring quantities related to the rate at which an injected fluid will enter the individual layers of a reservoir interval into which a well has been completed, comprising: injecting a temperature pulsing fluid into the reservoir interval in a known amount, at a known temperature different from the temperature of the reservoir interval, and within a known relatively short time period; measuring the rate with depth of the change of temperature within the well while the temperature within the well is recovering from the change caused by the injection of the temperature pulsing fluid; and determining, from said measured rate with depth of temperature change, a rate with depth of fluid inflow that corresponds to the distribution of heat due to the inflow of said temperature pulsing fluid by utilizing the measured information in a mathematical relationship substantially equivalent to: where To original formation temperature before injection of fluid, T1 temperature of fluid injected into the formation, T(t) observed wellbore temperature, t1 length of injection cycle, t time measured from instant injection of fluid is stopped, Nu mCpf/4 pi Keff m mass injection rate of fluid per unit of formation thickness, Cpf heat capacity of fluid phase, Keff effective thermal conductivity of combined rock and fluid phase.