| Abstract |
A study of thermodynamic (temperature, pressure) measurements logged at completion stage of wells of Los Humeros geothermal field, Mexico, were carried out. A prominent feature is that some temperature profiles show a particular behavior, in some cases with thermal regression. Because this field is located in a volcanic environment, we applied static reservoir characterization techniques to identify both the continuity of rock formation and the influence of structures on thermodynamic parameters of this reservoir. For this study, we used information obtained during the drilling and completion stages of the wells. Although the information corresponds mainly to thermodynamic measurements and transient pressure tests, these correlate with fluid circulation losses and lithological profiles. Through the processing of the thermodynamic measurements, we obtained gradient profiles of temperature and pressure. The analysis used in the completion stage allows one to determine the thermodynamic parameters of the reservoir at initial conditions and identify the thickness of the rock formation that, in some cases, could be used for exploitation. A special behavior we observed are particular trends in the profiles of the thermodynamic variables of each well after completion. Some of these peculiarities are thermal regressions with different temperature decreases, different lengths and depths. After selecting the profiles with similar behavior, we identified that these correspond to wells that group geographically by region although the lengths of the profiles and the magnitudes of temperature reduction are different. These results can be used to make decisions about the right time to carry out production tests, which are useful for determining best exploitation designs. Similarly, these thermodynamic analyses can be the technical basis for making decisions on the best depth of completion and for selecting the thickness of exploitation that assures the productivity of future wells. |