Matrix to Re-enter Kambuna #1 Well

Matrix Oil NL plans to re-enter its West Kambuna # 1 well after independent third-party studies have estimated gas in-place figures ranging from 0.6 to 4.5 trillion cubic feet and condensate ranging from 40 to 320 million barrels in the Kambuna/West Kambuna accumulation, these figures representing the range from 50% chance to 10% chance.

The exploration well drilled late last year is located in the company’s 75% controlled Asahan Offshore Production Sharing Contract offshore in the North Sumatra Basin of Indonesia.

There are intersecting gas bearing sandstones in the primary target Belumai Formation which were cased off and drill-stem tested over the interval between 7467 feet and 7525 feet. “Given the shows and porosities recorded and the electric log analysis that indicated gas pay, it was unusual that the test failed to flow hydrocarbons,” stated Matrix. The results of the drill-stem test suggested that the formation in the well-bore was impermeable and could be due to either:

  • An intrinsic lack of permeability in the section, an unlikely scenario given the porosities of up to 22% that were recorded or
  • Damaged caused to the formation by the drilling fluids as a consequence of the hole remaining open for an inordinately long time before being cased off because of problems with the logging tool.
  • Matrix said that it was continuing its analysis to understand the lack of permeability in the reservoir as well as engineering studies to determine if techniques are available to stimulate such low permeability gas reservoirs to unlock the large gas accumulation at West Kambuna/ Kambuna.

    The West Kambuna well is located 3.5km south west of Kambuna # 1 discovery that has been tested at 14 million cubic feet of gas plus 990 barrels of condensate per day. Pressure data collected from drill stem testing of the West Kambuna well showed that the gas bearing sections in both wells were in pressure communication.

    The West Kambuna 1 well was suspended in such a manner that is can be easily re-entered .It is examining the possibility of re-drilling the primary Belumai target by drilling a second deviated section from the existing well bore with a core being cut in the reservoir section to better determine the cause of the lack of permeability in West Kambuna 1. This re-entry will be undertaken in the middle of this year.