The Geology and Structural Style of the Juha Gas Field, Papua New Guinea

The Juha Anticline in the jungle-covered highlands of Papua New Guinea was drilled by three crestal wells in the 1980’s and discovered gas-condensate in a Lower Cretaceous clean quartz sandstone reservoir. The Juha-4 and Juha-5 wells drilled in 2007 further delineated the structure and defined a separate North Juha compartment. The Juha structure is 25 km long and up to 8 km wide and is traversed by a number of seismic lines, some of which are of moderate to good quality allowing the structure to be interpreted. Unlike most structures in PNG the seismic lines reveal the nature of the overlying Pliocene-Pleistocene sediment which help to define the depth of burial and timing of deformation. The wells and seismic data suggest that the Lower Cretaceous sandstone reservoir was buried by 1.5 km of Cretaceous shale, the regional seal, and 1.5 km of Miocene limestone as well as more than 1.6 km of Pliocene-Pleistocene sediment prior to uplift and erosion. To constrain the timing and style of extensional and comp...