Kina Petroleum Ltd.’s much-hyped wildcat in northern Papua New Guinea has hit an unexpected problem.
Raintree-1, the first well to be drilled north of the highlands in decades, has encountered volcanic rocks. The well was targeting a strong seismic reflector that was interpreted as a carbonate reef structure at the edge of the underexplored Ramu basin.
However, at a well depth of 1,088 m, the bit passed into volcanic lithology, the age and significance of which is still being evaluated.
The current plan is to continue to 1,200 m prior to making a logging run.
The result is reminiscent of a similar mistake made in Bass Strait by Planet Oil group in the 1960s with Sailfish-1, which targeted what was purported to be a classic dome structure, only to find it was volcanics.
Kina nevertheless says the igneous rock does not necessarily kill the Raintree prospect. A good sealing unit was encountered at 1,000 m and the follow-up prospects at Kwila and Sogerum will target a shallower Plio-Pleistocene sandstone reservoir down dip of active gas seeps on the northern flank of the Banam Anticline.
The presence of volcanics, however, does send a note of caution because igneous rocks often alter source rocks and impede hydrocarbon migration as well as altering the potential for reservoir, trap, and seal.