| Title | Casing Failure in Shallow Formation Based on Geochemical Properties and Casing Integrity Data in Patuha Geothermal Field |
|---|---|
| Authors | Ingria Yunandra Muhammad ARRASY, Randy Wijaya ATMAJA |
| Year | 2020 |
| Conference | World Geothermal Congress |
| Keywords | geothermal, geochemical properties, wireline logging, magnetic thickness tools, downhole video, casing integrity |
| Abstract | Casing integrity is one of important values for old geothermal well. Most of the casing have bad properties after the well being produced, the source of issue is because of the expanding and shrinkage temperature values in the well. Sudden change on temperature could make the casing cracking, deformation, or hole for the worst condition. PPL-Z was drilled on 1997 and one of the production well in Patuha field in West Java, Indonesia. The Patuha field itself is a vapor dominated geothermal system with 55 MW Power Plant capacity and had been operating since 2014. After 4 years of PPL-Z well being produced, there is a sudden change on geochemical properties that saying the well became wetter. Decreasing value of entalphy and increasing magnesium in water has proved the well had a non reservoir water breakthrough. Concurrent with the result of geochemical properties change, a well investigation is conducted to find the source of problem. Magnetic Thickness Detector (MTD), pressure temperature spinner (PTS), and Downhole Video become the best choices of tools with the current well condition. The intervention objective was to check the 13 3/8†and 20†casing for the purpose of well integrity current evaluation. Therefore, the data was acquired through the well interval from surface to 854 meters. The 9 5/8†casing liner have maximum metal loss up to 5.6% and the casing 13 3/8†casing wall have maximum metal loss up to 47.2%. PTS survey have defined a reverse temperature in 176 meters and change of spinner speed at the same depth. The result of downhole video provides the most reliable indication that there is a hole on casing with depth near the surface ground level. A series of recommended actions were taken to make sure no further environmental impact on the field and keep the well safely produced. |