Assignee:
Schlumberger Technology Corporation - New York NY
International Classification:
E21B 4900
G01V 514
Abstract:
Method and apparatus for determining the hydrogen and carbon densities of oil in situ in a subsurface geological formation are proposed which utilize the response of a neutron porosity tool to some oils. Apparent porosity derived from a neutron porosity investigation tool, which measures spatial neutron flux distribution, is compared to the porosity derived from a second investigating tool whose response is not or at least is less sensitive, say, to the hydrogen density of the formation fluid than is the neutron porosity tool. The magnitude of the difference is indicative of the hydrogen and carbon densities of the oil.