| Title | Productivity Analysis and Acid Treatment of Well AZ-9AD at the Los Azufres Geothermal Field, Mexico |
|---|---|
| Authors | Armenta, Magaly Flores; Barajas, Elvia Nohemi Medina; Rodriguez, Marco A. Torres |
| Year | 2006 |
| Conference | Geothermal Resources Council Transactions |
| Keywords | Power Plants; acid job, Los Azufres, stimulation treatment, enhanced production |
| Abstract | Well Az-9AD is located in the northern zone of Los Azufres geothermal field and it was drilled from Junuary 7 to April 22 on 2003, to a total depth of 1500 m. The well produced 22 t/h of dry saturated steam, which was found to be lower than expected, despite the persistent drilling losses in the openhole section and good thermodynamic conditions. Early testing and survey analysis indicated that the low output of Az-9AD was caused by considerable drilling induced wellbore damage in its open hole section, where 1326 m3 (8341 barrels) of mud were lost. Skin factor of 16 was causing additional pressure drop equivalent to 41 bars, reducing its optimal flow rate. The success of earlier acid treatment jobs in Mexico and the analysis of the available information encouraged the company to apply the same technique for this well during 2005. Acid treatment of well Az-9AD introduced very significant improvement in the wellbore showing 174% increase in production capacity. The results of this job, have been used for encouraging new stimulation programs, such as those in wells Az-56R and Az-9A located in the north zone of Los Azufres geothermal field. |