METHOD FOR THERMAL INVESTIGATIONS OF WELLS Russian patent published in 1999 - IPC

FIELD: oil and gas production industry. SUBSTANCE: method relates to investigations of wells at control for development of oil deposits and it can be used at field geophysical investigations of ecological condition of upper levels so as to detect low-capacity (> 0.5 cu.m/day) transfer flows after surface casing. Method implies performing groups of measurements by means of thermometer after termination of thermal disturbance within interval of investigation and analysis of temperature setting pace. Period of thermal disturbance within investigation interval is chosen from following relation: t < t_sc = 0,2(R_sc-R)²/a, where R_sc - radius of surface casing; R - radius of string; a - thermal conductivity of medium between string and surface casing. In addition, secondary thermal disturbance is performed in sign-changing manner in relation to initial temperature. Application of aforesaid method allows for enhancing efficiency of investigations in conditions of unstable temperature background for separation of liquid movement after surface casing with filtration of liquid in horizontal and vertical directions. Realization of aforesaid method also allows for defining wells in which salinization of fresh water sauces takes place due to transfer flows after surface casing, and also for defining wells where fresh water escapes to low-lying levels and this is important for environment control. EFFECT: higher efficiency. 1 cl, 3 dwg, 2 ex