Abstract

PT. Badak NGL. CO. and VICO have operated a gas-transportation system between the Badak gas plant and the Bontang LNG plant for the last 15 years. The two existing lines of 36" and 42" diameter from Badak field to Bontang were constructed during 1976 and 1983 respectively and a new line of 36" is still under construction. The lines run parallel to each other approximately 5 meter apart in soil depths of up to 4 meter with the length of each line approximately 57 Kilometers. The existing pipelines can supply a feed gas flow-rate of 2,750 MMSCFD at its Maximum Allowable Operating Pressure (MAOP) of 910 and 1200 Psig for 36" and 42" Pipelines respectively. (Figure 1, 2, 3, 4 and Table 1 & 2)

The pipelines must be able to deliver gas as required without any interruption for the achievement of the committed production of LNG and LPG in a safe, reliable and efficient manner.

For this reason, a great deal of effort has been placed on a condition monitoring program utilizing high resolution magnetic flux pigging of British Gas Electronic Pig Inspection Survey.

This paper will present the pipeline inspection program results which were done in 1991–1992. The program provided the company with reliable and accurate information with respect to the detection and sizing of features, distinguishing between internal and external features, interpretation of the features, estimated pressure ratio and selected priority.

With the British Gas Electronic Pig Inspection Survey and its comprehensive repair program accomplished, it will provide confidence that the actual condition of the pipelines are in good condition.