Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
372 words
A reflection seismic system for obtaining the interval velocity of seismic signals in a subsurface layer in an earth formation bound by a shallower and deeper reflector, the normal travel time in the layer and the layer thickness comprising: first means for generating a first downwardly propagating seismic signal at a first location, second means for generating a second downwardly propagating seismic signal at a second location, a known distance from said first location, and at a different time, a plurality of means for detecting reflections of the seismic signals and providing corresponding signals, and V, t and H analog computing means connnected to the detecting means for providing signals V, T and H corresponding to the interval velocity, to the normal travel time and to the layer's thickness H, respectively, in accordance with the signals from the detecting means, in which the analog computing means includes means receiving the signals from the detecting means for providing a signal S corresponding to the distance between the generating means and for providing signals corresponding to coefficients B 0 , C 0 , C 1 , C 2 , C 3 , C 0 ', C 1 '; C 2 ', C 3 ' for each detecting means in accordance with the signals from the detecting means and the following equations: T.sub.1 = B.sub.0 + B.sub.2 x .sup.2 + B.sub.3 x .sup.3 , (1) T.sub.2 = C.sub.0 + C.sub.1 x + C.sub.2 x .sup.2 + C.sub.3 x .sup.3 and (2) T.sub.3 = C.sub.0 ' + C.sub.1 ' x + C.sub.2 ' x C.sub.3 ' x.sup.3 where (3) T 1 , t 2 and t 3 are the time differences of reflection signals from the reflectors at the detecting means, X as used in equation (1) is the distance from the first generating means to the detecting means, and X as used in equations 2 and 3 is the distance from a mid-point between the two generating means to the detecting means, and signal means for providing signals V, T and H in accordance with signals S, B 0 , C 0 , C 1 , C 2 , C 3 , C 0 ', C 1 ', C 2 ' and C 3 '.
Claim 2
Dependent Claim
372 words
A reflection seismic system for obtaining the interval velocity of seismic signals in a subsurface layer in an earth formation bound by a shallower and deeper reflector, the normal travel time in the layer and the layer thickness comprising: first means for generating a first downwardly propagating seismic signal at a first location, second means for generating a second downwardly propagating seismic signal at a second location, a known distance from said first location, and at a different time, a plurality of means for detecting reflections of the seismic signals and providing corresponding signals, and V, t and H analog computing means connnected to the detecting means for providing signals V, T and H corresponding to the interval velocity, to the normal travel time and to the layer's thickness H, respectively, in accordance with the signals from the detecting means, in which the analog computing means includes means receiving the signals from the detecting means for providing a signal S corresponding to the distance between the generating means and for providing signals corresponding to coefficients B 0 , C 0 , C 1 , C 2 , C 3 , C 0 ', C 1 '; C 2 ', C 3 ' for each detecting means in accordance with the signals from the detecting means and the following equations: T.sub.1 = B.sub.0 + B.sub.2 x .sup.2 + B.sub.3 x .sup.3 , (1) T.sub.2 = C.sub.0 + C.sub.1 x + C.sub.2 x .sup.2 + C.sub.3 x .sup.3 and (2) T.sub.3 = C.sub.0 ' + C.sub.1 ' x + C.sub.2 ' x C.sub.3 ' x.sup.3 where (3) T 1 , t 2 and t 3 are the time differences of reflection signals from the reflectors at the detecting means, X as used in equation (1) is the distance from the first generating means to the detecting means, and X as used in equations 2 and 3 is the distance from a mid-point between the two generating means to the detecting means, and signal means for providing signals V, T and H in accordance with signals S, B 0 , C 0 , C 1 , C 2 , C 3 , C 0 ', C 1 ', C 2 ' and C 3 '.
Claim 3
Dependent Claim
176 words
A system as described in claim 1 in which the V, T and H analog computing means includes D 0 signal means receiving signals S, C 0 , C 1 , C 2 , C 3 , C 0 ', C 2 ' and C 3 ' for providing a signal D 0 in accordance with the received signals and the following equation: D.sub.0 = {S/[C.sub.1 ' + C.sub.2 ' (2 C.sub.0 '/C.sub.1 ' + S.sup.2 C.sub.2 '/SC.sub.1 ') - S/[C.sub.1 + C .sub.2 (2 CO/C.sub.1 + S.sup.2 C.sub.2 /C.sub.1)}, (4) means receiving signals B 0 and D 0 for providing signal V in accordance with signals B 0 and D 0 and the following equation: V = √D.sub.0 /B.sub.0, (5) means receiving signals B 0 and D 0 for providing signal H in accordance with signals B 0 and D 0 and the following equation: H = √(B.sub.0 D.sub.0)/4 (6) and means receiving signal B 0 for providing signal T in accordance with signal B 0 and the following equation: T = B.sub.0 /2. (7)