| Title | MATRIX STIMULATION TREATMENT OF GEOTHERMAL WELLS USING SANDSTONE ACID |
|---|---|
| Authors | R. C. M. Malate, J. J. C. Austria, Z. F. Sarmiento, G. Di Lullo, P.A. Sookprasong, E. S. Francis |
| Year | 1998 |
| Conference | Stanford Geothermal Workshop |
| Keywords | acidization, Philippines |
| Abstract | Mud acid (HCl-HF) is generally used in stimulation of oil and geothermal wells that suffer formation damage but its application has been limited to restoring the natural permeability of the formation. A combination of rapid spending with clays and silicates, matrix unconsolidation in the near wellbore and subsequent precipitation of various reaction by products has somewhat restricted the usefulness of mud acid for matrix stimulation treatments. This paper discusses the application of a new acid system (sandstone acid) recently used in treating sandstone forinations at some geothermal wells in the Philippines. The new HF acid compared with the usual mud acid systems has lower reaction rate and limited solubility with clays, but higher reaction rate and dissolving power with quartz. |