Fracture Characterization of the Elk Carbonate Reservoir, Papua New Guinea.

Abstract

The Elk trend gas field is situated in a frontal location of the Papua New Guinea Fold Belt. The Elk reservoir is Miocene carbonate ramp to deepwater basinal Puri Limestone and Eocene to Oligocene shelfal Mendi Limestone. FMI analysis from the Elk-1 well has constrained the in-situ orientation and distribution of fractures, and provides some indication of fracture aperture, but information is constrained to the wellbore. Offset data comprising FMI logs, structural core analysis, and outcrop studies provide information on fracture morphology, generating mechanisms and spacing. These have been used to generate models for the Elk reservoir. The Elk-1 well from DST-1 and DST-2 demonstrated extreme permeability and can only be explained by a significant well connected natural fracture network in the relatively tight section penetrated. Within the Elk reservoir, fractures were divided into producing and non-producing from wireline logging based upon detailed analysis of wellbore temperature, fracture location, orientation and morphology. A limited number of the fractures flowed gas during logging but these have facilitated interpretation of the geometry and interconnectivity of the fracture network outside the wellbore.