By looking at, and understanding how geological processes work today, it is possible to reconstruct the earth’s development and understand how, where and when fossil fuels were created and trapped, and answer the following questions: What did the landscape look like? Where did the organic rich source rock develop? Where were the high porosity reservoir rocks deposited? How did the continents move to shape structures that today trap oil and gas?
Different sources
To address these questions, several sources of information are utilised including: satellite images of the earth’s surface, gravity and magnetic data, geological field work, seismic data, drilling of wells, and the sampling and recording of measurements in the wells. These are all important contributors to cracking the code.
“We want to uncover all the hidden codes that can lead us to oil and gas discoveries in the ground”, Tore Lilloe-Olsen, Director Group Exploration and Subsurface at DNO, adds:
“Smart exploration is all about solving the puzzle faster and more efficiently than our competitors, to use gathered data with knowledge and flair. DNO has a very skilled and extremely capable staff of subsurface specialists, and we are proud to be recognised as a company that notwithstanding limited resources produces quality results and outperforms competitors.”
The Tawke field is located on a former continental shelf, with extremely organic rich source rocks and carbonate reservoir rocks, that were later uplifted and folded during the formation of the Zagros Mountains, a result of continent collision. The folding of the sediment package created the anticlines that later trapped the oil and gas. The uniqueness of this area is that it is possible to study both the rocks and the geological processes at the surface in the field, and combine this with all kinds of subsurface data. It is simply a paradise for geologists.
To minimize costs, DNO initially used a scarce grid of 2D seismic to define potential drilling targets. If a discovery is made, 3D seismic data is required to interpret and understand complex subsurface geometries and to plan on how to best appraise and later produce the field.
“We will never stop being surprised or learning in this business. As technology develops and our understanding improves, it is possible to revisit non-successful areas and find new oil. Lundins Avaldsnes/Aldous discovery in the North Sea is a good example of exploration excellence. New thoughts in a well known area, a bit of flair and luck are sometimes necessary to hit the black gold,” says Lilloe-Olsen.