Publications

T gas field is located at a water depth of about 90 m, +/- 120 km off North coast of Bali (Figure 1), and has been developed with five horizontal subsea wells which are placed on the top of the structure. Based on the production history so far, a major fault crossing the structure in a north-south direction has been interpreted as a transmissibility barrier. The fault divides the structure into two pressure compartments, a west compartment which four wells are placed at and an east compartment which the rest is placed at. The pressure gradient data from exploration wells indicate a common GWC in both compartments. The field has been on production since May 2012 with a plateau rate around 300 MMSCFD. Due to the limitation by gas market demand one well in the west side had been shut-in from 2012 to 2015. Consequently a monitoring well had been available then. The static p/z plot of this monitoring well in the west side shapes at the early time a straight line, at the middle time a deflection curving upward, and at the late time curving downward. To understand what parameter affected the upward and downward curve, Havlena Odeh, Cole and non-linear rock compaction curve were used. On the other hand, the static pressure of an eastern well has started showing a clear deviation from that of the other western wells since the well was shut-in following its water breakthrough. With a common geological settings being preserved between east and west, pressure compartmentalization sealed by the major fault was proposed for explanation about the pressure deviation. Results from the MBAL analysis were used to generate possible ranges of connected gas volume and reliable forecast that can be used to estimate the recoverable reserves of T Field.