VARIATION OF VELOCITY WITH LITHOLOGY 0 5 10 15 20 25 VELOCITY (KFT/SEC) AIR METHANE PETROLEUM WATER MUD SHALES SANDSTONE LIMESTONE SALT DOLOMITE GYPSUM

TYPICAL MATRIX AND FLUID DENSITIES MATRIX DENSITY ma (gm/cm3) SAND (PURE QUARTZ GRAINS) LIMESTONE, PURE DOLOMITE, PURE AVERAGE FOR CARBONATES GYPSUM ANHYDRITE SALT SHALE 2.65 2.71 2.85 2.80 2.32 2.96 2.05 - 2.1 2.6 - 2.65 FLUID DENSITY f (gm/cm3) BRAIN (DEPENDENT ON SALINITY) CRUDE OIL METHANE (10C . 760 mm Hg) 1.04 - 1.07 0.6 - 0.88 0.0007

CRITICAL ANGLE FOR REFRACTION  V1 V2 SIN  = V1 / V2 , SIN (90) = V1 / V2 WHERE :  = CRITICAL ANGLE

RAY PATH FOR A REFRACTION  V1 V2 SOURCE RECEIVE

REFLECTED WAVE V  X  Z l X t DIRECT WAVE

MULTIPLY REFLECTED WAVE  X V  Z l X t DIRECT WAVE REFLECTED WAVE

REFRACTED WAVE L1 L3 L2 V1  X  Z X REFLECTED WAVE WHERE 2l1 = DISTANCE IN LAYER 1 l2 = DISTANCE IN LAYER 2 t

NORMAL-INCIDENCE REFLECTION AND TRANSMISSION COEFFICIENTS DENSITY r1 VELOCITY V 1 DENSITY r 2 VELOCITY V2 WHERE: r1 = DENSITY OF LAYER 1 V1 = VELOCITY OF LAYER 1 r 2 = DENSITY OF LAYER 2 V2 = VELOCITY OF LAYER 2