A composite lithology log while drilling
A new method for producing a computerized composite lithology log (CLL) while drilling by integrating MWD (measurement while drilling) and surface data is described. The CLL integrates three types of data (MWD mechanical, MWD geophysical, and surface cuttings) acquired during drilling, in three time stages: (1) Real Time. MWD drilling mechanical data including the rate of penetration and the downhole torque. This stage would provide bed boundaries and some inferred lithology. This would assist the driller with immediate drilling decisions and determine formation tops for coring, casing point, and correlation. (2) MWD Time. Recomputation of the above by adding MWD geophysical data (gamma-ray, resistivity, neutron-density). This stage would upgrade the lithology inference, and give higher resolution of bed boundaries. (3) Lag Time. Detailed analysis of surface cuttings to confirm the inferred lithologies. This last input will result in a high-quality CLL with accurate lithologies and bed boundaries. The log will serve the geologist as well as the driller, petrophysicist, and reservoir engineer. It will form the basis for more comprehensive formation evaluation while drilling by adding hydrocarbon and MWD log data.
- Research Organization:
- Anadrill/Schlumberger, Sugar Land, TX (USA)
- OSTI ID:
- 5878565
- Report Number(s):
- CONF-880301-
- Journal Information:
- AAPG Bull.; (United States), Vol. 72:2; Conference: Annual meeting of the American Association of Petroleum Geologists, Houston, TX, USA, 20-23 Mar 1988
- Country of Publication:
- United States
- Language:
- English
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