Maputo, Mozambique – Sasol recently announced the completion of the first-ever 3-D onshore seismic programme in Mozambique. This involved the acquisition of 115 square kilometres (km2) of data in the Inhassoro field, which is part of the onshore Production Sharing Agreement (PSA) licence area.

To be developed in phases, the first phase of the PSA licence area development proposes an integrated oil, LPG and gas project adjacent to Sasol’s existing Petroleum Production Agreement (PPA) area. Sasol has made significant progress on Tranche 1 of the PSA Development as approved by the Council of Ministers on 26 January 2016.

Senior Vice President for Sasol Exploration and Production International, John Sichinga, highlighted that: “The acquisition of the 3-D seismic data in the Inhassoro field will significantly enhance our understanding of the structure of the oil accumulations through better resolution and more defined characterisation of the reservoir. While initial results appear encouraging, it is still too early to give further detail.”

Geofizyka Torun of Poland was contracted by Sasol to acquire 2D/3D seismic data using Vibroseis trucks. These send an acoustic wave into the ground and when the wave is reflected at boundaries between rock layers, an image of the subsurface is generated. The principles are similar to ultrasound technology used in the medical field. Future well locations can be optimised based on the generated images.

Sasol has previously conducted 3-D seismic surveys offshore Mozambique – 1 836 km2 and 2 100 km2 in the M10/ Sofala and Blocks 16/19 respectively – but this is the first time a 3-D seismic campaign has been conducted onshore.

The seismic acquisition programme now moves to the Pande field within the PPA licence area, where 42 km2 of 3D seismic data will be acquired.

Sichinga further provided an update on the PSA drilling campaign, saying that the drilling of the first two wells have been completed.

“The tests conducted thus far have produced encouraging results. During the course of the drilling of the second well, we encountered previously unknown accumulations of hydrocarbons within the development and production area, which indicate the presence of both gas and oil. We have issued a Notice of Discovery to the Mozambican authorities as per the PSA and will continue our evaluation of the data.”