测井题：已知泥质砂岩地层的GR=45API,泥岩地层的GR=100API,纯砂岩地层的GR=10API.求泥质地层的泥质

△GR=(GR-GR砂)/(GR泥-GR砂）=0.389
Vsh=(2^(GCUR*△GR)-1)/(2^GCUR-1)
老地层　GCUR=2
Vsh=23.8%
新地层　GCUR=3.7
Vsh=14.3%