This paper was prepared for presentation at the 47th Annual Fall Meeting of the Society of Petroleum Engineers held in San Antonio, Tex., Oct. 8–11, 1972. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by who the paper is presented. Publication elsewhere after publication in the JOURNAL paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made. provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines. To further the scientific aspect of temperature logging procedures and interpretation methods, theoretical models describing the exchange of heat between injection fluid, borehole, surrounding formation, and injection zone have been used to study; the borehole-fluid temperature during injection, as determined by rate, depth, and duration of injection, the temperature along the axis of the cylindrical system as it recovers under shut-in conditions from the disturbance due to injection, and the establishment of the formation-temperature disturbance due to injection of fluid. Comprehension of the heat-exchange phenomena involved has been stressed, rather than detailed matching of specific logs. In general, it was sought to establish what information a temperature survey could reasonably be expected to yield under "ideal" and actual field conditions. The results provide specific information concerning: - a criterion for running an injection temperature survey as a source of flow-rate data, - the effects of vertical heat exchange on temperature distribution during injection and shut-in, - the relation between time of shut-in and ability to discern the radial extent of the formation-temperature anomaly, and - the relation between rate and duration of injection and the radial extent of the formation anomaly. A principal conclusion from this study is that a temperature survey alone should not always be expected to yield volumetric flow information. Rather, a combination of temperature and flowmeter or tracer surveys should be conducted. Further, when injection has been going on for a considerable length of time, heat exchange within the formation can cause an anomaly of greater vertical extent than the injection zone itself. P. 1