Tullow explains its oil Exploration and Appraisal

Angus McCoss, Tullow Exploration Director

Our performance in exploration is marked by notable and consistent success. There’s no secret to it. It is down to teamwork. Strong exploration teams are built on a basis of openness, trust and creativity. They are equipped with the most appropriate and often highly innovative technology, have vast and diverse experience and a clear geological focus.

This is what makes us different, what gives us an edge. In a sense, this is Tullow’s unique selling point. Utilising our collective skills and integrating them for maximum performance, has led us directly to major discoveries such as those in Ghana and Uganda.

The right technology at the right time
In applying our scientific approach Tullow draws on another key determinant of success – applying the right technologies at the right time. We select the best methods and tools at each point of the exploration cycle from new venture identification through seismic acquisition, processing and interpretation to precise well location and drilling methods.

We continuously scrutinise our exploration portfolio selecting only the best leads to be matured into prospects before being drilled. Typically only the top 10% of the prevailing lead inventory will be drilled in any year.

Geology before geography

Only 0.5% of the surface of the earth has readily movable oil or gas beneath it. To target only the highest value quartile of this tiny ‘oil patch’, we limit ourselves to exploring less than 0.125% of the earth’s surface. This is a tough challenge and one which is best tackled through scientific methods.

Putting geology before geography means we focus on building prospective acreage positions and strengthening our business relationships in areas with well-founded potential for oil. For Tullow, this means we focus on three core play types and we leverage our capabilities in those plays across the world. The Group has 200 to 300 leads and prospects, covering all stages of evaluation from initial screening through to delivering commercial discoveries. Each of the core plays is proven to have first class potential and each comes with its particular value and challenges.

• Stratigraphic traps can have exceptional upside and often lie subtly within held acreage. We are developing proven expertise in this play and in particular in the vast potential that lies in the Equatorial Atlantic regions of West Africa and South America.
• Rift basins are a fundamentally rich setting for petroleum exploration and benefit from excellent source rocks and generally straightforward structural geology. Tullow has gained extensive expertise in this core play, mainly in Uganda.
• Salt basins – Salt is a first class seal and salt tectonics form a rich diversity of Salt Basin trap types. Tullow’s seismic acquisition, processing and interpretation expertise in Salt Basins provides a tangible competitive advantage, which we are applying to our acreage in Mauritania and Senegal.

None of us is as smart as all of us

Ultimately oil is found through creative teamwork. When recruiting and developing staff, we emphasise skills in play-making, prospecting and appraising. We also encourage and develop those who have particular technical expertise to deepen their skills, ensuring Tullow stays at the leading-edge of industry practice.




While Tullow values and fosters individual creativity in prospecting, this is amplified by imaginative teamwork and thorough scientific evaluation by multi-disciplinary teams. We extend our teams to include partners in the industry and governments, whose independent approach, local knowledge and basin-wide perspectives make a valuable contribution to exploration success.

Learning from experience

Oil and gas exploration always carries a significant risk of failure. But in this industry any failure helps us to become better. There is no blame or shame in a dry-hole, provided that it was drilled for the right reasons, after due scientific process gave a green light. Even the latest and the best technology and methods, such as advanced 3D seismic, cannot completely remove geological risks. This is especially the case when geological risks in new basins can only be calibrated by referring to distant wells. And they can be very distant.

For example, Tullow’s successful Venus-B well in Sierra Leone was 1,100 km from the nearest comparable discovery, in deepwater Ghana. Without these challenges, finding oil and gas would be easy. But such challenges, along with our occasional failures, help us to better understand the geological plays and the technology and methods we use, and to hone our interpretation skills. We learn equally from discoveries and from dry-holes. Planning and decisions are guided by the understanding that we garner in the course of both experiences.

Equally, what we decide not to do is often what sets us apart from the rest of the industry. Tullow’s successes in the Equatorial Atlantic are firmly based on our focus on Upper Cretaceous turbidites, whilst most of the industry concentrated on the younger Tertiary turbidite prospects elsewhere.

Building and developing exploration capability

Our capability owes a great deal to the way in which we can attract and retain people. The combination of our track record and our reputation for exciting and challenging geological projects makes us an attractive employer for some of the most experienced playmakers and prospectors in the industry today. The best geoscientists are independent thinkers who are also great team players and that’s why they feel at home with Tullow. Our Global Exploration Leadership Team (GELT) of 15 leading explorers has over 300 years’ experience and oversees the overall management of our exploration initiatives and ultimately decides which prospects will be drilled.

The team comprises two distinct elements which operate in a kind of critical tension, given their competing yet complementary responsibilities. There are regional exploration managers who work closely with the regional business units. There are portfolio managers for exploration, technology and new ventures, along with industry specialists. Their function is to assist, challenge and assure, as appropriate, in regard to technical, commercial and financial considerations.
Essentially, this means we get a rigorous and objective exploration process which sifts out weaker leads and concentrates on the most promising opportunities.

By Angus McCoss, Exploration Director

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