Casing inspection caliper surveys were conducted in ten (10) production wells in the Leyte Geothermal Production Field (LGPF) to examine possible deterioration of the production casing, which has been suspected as a result of long term continuous production of high velocity dry steam discharge. Surface manifestations of erosion were also observed at the wellhead and branchline. Casing deterioration compromises the integrity of the well that could result to casing bursting, collapse and even underground blowouts.

The caliper surveys were able to gather information on the internal casing condition which was used to determine the degree at which the casing was deteriorated or worn. The presence of inside casing wall anomalies was also detected. Considerable metal loss was measured in all the wells surveyed. Material deformation, scaling and even a possible wall opening were also detected in several wells. These data help define the physical integrity of the internal casing around which failure mechanisms or stresses that the well casing is subjected to under geothermal service conditions are evaluated.

The results of the caliper surveys serve as a reference for future well utilization and intervention strategies, which are preemptive measures to prevent further deterioration of the well and maximize, preserve or prolong the wells production capacity. Given the value of the caliper information, incorporating periodic caliper surveys in the long term monitoring and preventive maintenance program of wells should continue.

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