Marcel Schlumberger

Marcel Schlumberger was a French mechanical engineer who, together with his physicist brother Conrad, founded the oilfield services company that became Schlumberger Limited. While Conrad supplied the underlying electrical resistivity theory, Marcel engineered the surface and downhole equipment that turned the idea into a working field technique, and the brothers' first electrical well log, recorded on September 5, 1927 near Alsace, France, is generally regarded as the founding moment of modern well logging. Marcel went on to lead the growing company's engineering and manufacturing operations as it expanded from a French surveying partnership into a worldwide oilfield services business.