The Estimation of Water Injection Profiles From Temperature Surveys

Abstract

Abstract The heat flow processes determining the injection and shut-in temperaturelogs in a water injection well have been analyzed and the theoretical basis fordetermining the water injectivity profiles from the temperature logs has beenpresented. Both the injection and the subsequent shut-in logs are necessary toresolve the injection interval into relative water intake strata; the former, to provide an accurate estimation of the thicknesses of the strata, and the latter to indicate themajor and minor intake rates into the strata. A procedure is described forestimating the injectivity profile from the temperature logs and is applied toseveral temperature logs. For a water injection well, a comparison is made ofthe injectivity profiles obtained from the core analysis, the spinner survey, and the temperature logs. Introduction In secondary recovery of oil by water flooding, the injectivity profile isneeded to obtain diagnostic evaluation of water intake distribution over theinjection interval. If the distribution is unfavorable among the variousstrata, corrective measures can be taken to provide better control. Numerous methods have been developed for determining the injectivity profilefrom water velocity measurements in well bores. Often, dependence is placedupon core analyses and/or electric logs for estimating the relative waterintakes over the injection interval. In many cases, the temperature log methoddescribed herein will give results more diagnostic than those obtained throughuse of the other available methods inasmuch as it is based upon the study oftemperature disturbances in and around the well bore as a function of waterflow in the well bore and in the formation. This method is the result of analyses of a number of temperature surveysmade in water injection wells to determine the point of entry of the water intothe formation. The material in this paper is presented in two sections: thefirst deals with the theoretical study of temperature survey data, and thesecond deals with the field application. T.P. 3637