Classification and Logging Modes of Dolomite Reservoirs in the Tarim Basin,Northwestern China

There are vuggy,pinprick and intercrystalline pore in dolomite of the Tarim basin.Dolomite can be classified as compact dolomite,pinprick dolomite and vuggy dolomite by the characteristics of dolomite pore.Three types of dolomite are quite different in logging features,which can be showed in the data and curve shape of logging.Compact dolomite has the worst reservoir capability and distinct logging features:high resistance,low CNL and high density.Vuggy dolomite,low electric resistivity,high CNL,low density,zigzag shape of logging curve and obvious difference of dual-lateral electrical resistivity curve,has better capability and more obvious logging features than pinprick dolomite which has low electric resistivity,high CNL,low density and left or right protruding' shape of logging curve.The logging mode for pore identification of dolomite in the Tarim basin has been based on these characteristics.It is effective when the mode was applied to some wells in the Bachu and Tazhong areas,the reservoir lengthways distribution characteristic and the reservoir space degree of dolomite have been found.It is instructional for further oil exploration in the Tarim basin.