The Maharaja-Lela Exploration 2010 Campaign, The Key Opener for an Additional Development

Biteau, Jean-Jacques R.; Balusseau, Bernard; Chevalier, Christian; Liberelle, Emmanuel
Geoscience, TOTAL, Paris, France.

Description:
The recent drilling of two wells in 2010, ML5B2 and ML6C2, has been safely carried out by the Brunei Total's affiliate resulting in successful exploration of gas condensate bearing deep targets and high pressure regimes reaching 2.15 emw (17.95 lb/gal).
ML6C2 is the deepest well ever drilled in Brunei with a 5725m/RT TD.

In addition to ML-4 and MLJ2-06 successfully drilled in 2008, these 2010 wells have unlocked the Maharaja-Lela South development phase with a new platform able to reach five undeveloped faulted panels.

Results and conclusions

Structure
Five 3D seismic surveys acquired between 1989 and 2004 have been reprocessed /merged up to PreSTM.
Block B is located in a structurally active zone within a highly subsiding part of the Baram delta shelf where a set of faults delineates several narrow south dipping faulted and elongated monoclines.
All main faults appear syn-sedimentary with variable expansion within the panels. Lateral seal efficiency controls trap geometries and was confirmed by the two 2010 wells.

Sedimentology and petrophysics

The multilayered individual reservoir units correspond to good quality estuarine, shoreface sands generally interbedded with thin shale layers. Syn-sedimentary faults impact thickness of individual sequences.
Log correlations show good lateral continuity of thick parasequences with limited petrophysical variations.
Pre-well evaluation of the net reservoir volume results from the combination of N/G and average net porosities. The methodology successfully applied in MLJ area where the shale intervals are limited, provides a link between N/G, porosities and saturations in every reservoir layer.
Petrophysical parameters were extrapolated assuming some reduction of porosity implying lower values for N/G and have been confirmed in the lower objectives by the two wells.

AAPG Search and Discovery Article #90155©2012 AAPG International Conference & Exhibition, Singapore, 16-19 September 2012