In this paper

Monte Carlo simulation is used to calculates thin bed responses for different detector spacings of longer than zero spacing

the relationships between photon flux and spacing at various formation densities

and the "spine-rib" figures for long

middle and short spacings.The results show that the spacing affects the longitudinal resolution

statistical error

sensitivity

and mudcake compensation effect of density logging tool.For a density logging tool of high-resolution(20 cm) and high measurement precision

the long

middle and short spacing should be about 38

20.5 and 11 cm

respectively.