| Title | KEYS TO SUCCESSFUL DRILLING IN MAHANAGDONG |
|---|---|
| Authors | Mario A.Talens, Edwin B.Herras, Manuel S.Ogena |
| Year | 1998 |
| Conference | Stanford Geothermal Workshop |
| Keywords | Mahanagdong, Philippines |
| Abstract | The Mahanagdong sector is one of the four development sectors within the Leyte Geothermal Production Field and has been developed to supply 180 MWe of steam capacity. Drilling activities in Mahanagdong began in July 1980 by drilling the first deep well, well MG-1. To date, a total of thirty seven (37) wells have been drilled in the area, twenty eight (28) for production and nine (9) for reinjection. The success rate of drilling and completing deviated wells in the area to attain their geologic objectives is only 44%. The principal cause of drilling problems in the open hole section of wells in the Mahanagdong sector is the limited ability of the loss zones to accept cuttings despite initial massive mud circulation losses leading to a shift to drilling with water. The volume of cuttings generated with further drilling and which can not be absorbed by these loss zones eventually leads to stuck pipe and subsequent early termination of the well. A modified drilling strategy, well design revisions and the use of the two-liner system are some of the solutions implemented which substantially improved the success rate of completing the last five wells and following the programmed design and objectives. |