CSEM performance in the light of well results

These studies evaluated the results from wells drilled on prospects covered by CSEM data.

Largest database

Of the 86 wells with associated CSEM data, 50 are exploration wells drilled after CSEM data acquisition and 36 are calibration surveys acquired over an existing discovery or a dry well to test the technology. This represents the largest available database.

Hydrocarbon drilling success rates

The Leading Edge article CSEM performance in light of well results (copyright SEG) demonstrates that prospects showing a significant resistive anomaly are roughly twice as likely to contain hydrocarbons compared with prospects that do not exhibit a resistive anomaly. This study addresses the technology’s ability to detect hydrocarbon accumulations but does not take commerciality into account.

Commercial drilling success rates

The First Break article Controlled source electromagnetic technology and hydrocarbon exploration efficiency (copyright EAGE) demonstrates that when non-commercial discoveries are counted as dry wells, the drilling success rate is 50–70% for wells drilled on prospects with a significant EM anomaly compared with 5–14% for wells drilled on prospects without a significant EM anomaly.

An integrated approach

These studies clearly show that CSEM technology, when applied in suitable areas, can significantly reduce exploration risk and improve drilling success rates. To achieve the best results, analysis and interpretation of integrated data, including all the available CSEM, seismic and well data, and regional geological knowledge, must be undertaken.

Also read:

• World Oil article: Value creation using electromagnetic imaging
• False negatives and positives in the interpretation of EM data (copyright SEG)