| Title | RESULTS OF LARGE-DIAMETER WELL DRILLING IN PHILIPPINE GEOTHERMAL FIELDS |
|---|---|
| Authors | Sta.Ana, F.X.M., Sarmiento, Z.F., Saw, V.S., Salera, J.R.M. and Retuya, R..E. |
| Year | 1997 |
| Conference | Stanford Geothermal Workshop |
| Keywords | |
| Abstract | A large diameter casing design was adopted for 34 wells drilled in the Philippines using 13-3/8î production casing in combination with 9-5/8í slotted liner to improve well output and to reduce space requirement in collaring the wells. Well test results indicate an increase in production by as much as 250% compared with wells using the usual string combination of 9-5/8î and 7-5/8î. In the 600 MWe Leyte Geothermal project alone, a reduction of about 19 wells in the total number of wells to be drilled was achieved because of this newly adopted casing configuration. This translates to a direct savings of US$23-48 million, excluding those saved from a) developing new production and reinjection pads; b) additional pipeline length; c) damage to environment rom new areas. However, various drilling problems vere encountered associated with collapsing formation and casing failures. These have been mitigated by appropriate drilling procedures, cementing and selection of casing materials. |