A Contribution to Electrical Log Interpretation in Shaly Sands

Simple quali tat ive methods a r e explained for identifying those shaly sands in a well that a r e most likely to contain oi l . A need for more p r e c i s e m e a s u r e m e n t of the var iab les that enter shaly sand ana lys is is indicated. F ie ld examples a r e given to i l lus t r a t e the methods . A theore t i ca l d i scuss ion of the quantitat ive in te rpre ta t ion of shaly sands is given as a bas i s for d i scuss ion and as a guide for the fu ture . While not genera l ly capable of p rac t i ca l applicat ion at the p r e s e n t t ime because of the lack of sufficient a ccu racy of the e l ec t r i c log data, these methods may become m o r e feasible in the future as a r e s u l t of the improved logging methods now being int roduced. Schlumberger Well Surveying Corp . , Houston, Texas