Abstract

The Badak Field is being developed to supply gas to the Badak LNG Plant under construction at South Bontang Bay in East Kalimantan. Gas Reserves have been proved in 66 separate reservoirs between 3,800 and 11,000 feet.

Gas production operations in a multiple reservoir field such as Badak are very complex. Wide variations in reservoir size and well deliverability make predictions of number of wells required and timing extremely difficult, particularly after the first few years. This problem has been simplified somewhat in recent years with the introduction of computer simulation technology. The numerical model used for Badak allows total simulation of the system from the reservoir through the delivery point to the LNG Plant. The program calculates simultaneous gas flow from a group of reservoirs through tubing and flowlines to a single delivery point. Individual well production rates are governed by deliverability potential of the well, tubing and flowline sizes through which the well flows, and pressure at the delivery point.

The model was first used to evaluate several alternative gathering system configurations. From these results, the decision was made to gather gas at three satellite sites and transport to a central point for processing. With this system flowlines are shorter which reduces tie-in costs and improves well deliverability because flowline friction losses are less.

Once the satellite gathering system concept was established, a 20 year simulation was undertaken to determine the number of completions required annually to meet a 550 MMCF/day LNG Plant demand plus provide 150 MMCF/day of standby capacity. Approximately 30 completions will be required initially to meet the plant demand with the number increasing gradually to near 65 as the various reservoirs approach depletion. Actual well and reservoir performance will be incorporated in the model once the field goes on production to refine completion requirements.