| dc.description.abstract | A fluid injection test was made at the two wells with distance of 39m at the TCDP drilling site. The fault zone as identified from the drill cores were at the depth of 1111m and 1132 m, respectively. The two wells were perforated at the identified fault zone depth to keep the communication of te two holes. During the FIT experiment, the pressure was kept as constant at 4MPa to inject the tap water into hole C with the observation and analyze of fluid at hole A. The FIT experiment was made twice as the for 1st pre-FIT on Novenber , 2006 for the continuous of injecting constant pressure water at hole-C for 108.5 hours , The total amount of water used in the 1st pre-FIT was 450L.The 2nd pre-FIT was made in January , 2007 for injecting of water for 90 hours , and the total amount of injected water is about 50 L. The main FIT was made in April 2007, however, no gas and chemistry observations were made for the main-FIT. Thus, this thesis concentrates on the results for the two pre-FIT. For the 1st pre-FIT , after 68hours and 15 min. from the beginning of the experiment, we detected clearly effect of gas , and also of water at almost same time, and the water comes about 192hr after the experiment.
For the 2nd FIT , Gas’’ effect can’’t be detected until 75.25 hours after the experiement , the water chemical effect was detected at 110hr40min after the experiment. And the arrival of the water was difficult to detect due to its minor change in the flow. Even though the experiments of the two pre-FIT was only 2 months apart, the difference observed in these two experiments, suggesting the possibility of lower permeability of the fault zone for the 2nd pre-FIT. However, another possibility is the blog of the material in the perforated holes and in the fault zone. The exact reason for the difference is hard to be explained now. However, the arrivals of the signals from the communicated two wells as the gas coming first, then, chemical component, then, the fluid itself, bring some odds in the character of these components. Although no specific mechanism can be proposed now in this thesis, these observations are intriguing, and hopefully can bring some information to the future fault zone behavior studies. | en_US |