GSI 80
Ogle Petroleum Inc.
NORTHERN AND CENTRAL CALIFORNIA
MARINE SEISMIC DATA

Fact Sheet

The GSI (1980) series of Ogle Petroleum Inc. proprietary seismic data was collected by the vessel M/V "Edward 0. Vetter"  April 26 to June 6, 1980. A total of 1,531 line miles were collected in this survey.   The data were processed by GeoCenter, Inc. The processing sequence is shown in Exhibit A. The individual line mileages in the Eel River, Point Arena, Salinas and Santa Maria offshore basins are listed in Exhibit B.

The technical specifications and recording information are 
as follows:
* General	--	Stack: 4800% CDP
      Record Length: 5 seconds 
      Sample Rate: 4ms
* Source		--	2004 cu in airgun array
      --	Shot Point Interval: 25 m
* Instrument Parameters --  Instrument: DFS IV 
 	--  Filters: Hi 62, Lo 8
* Streamer Parameters	--  Cable Length: 2400 m 
      --  Number of Groups: 96
* Navigation -- SYLEDIS
      CDP Position 
      Spheroid: Clarke 1866 
      Projection: UTM
All lines are available in the following formats:
* 4800% CDP Stack, 48 tr/in, 2.5 in/sec.
* Wave Equation Migration, 48 tr/in, 2.5 in/sec.


The following supporting information may be obtained for  this survey.
* Reproductions of OPI Pacific Basin North Seismic Shot Point Base Maps, Sheets 1 through 13 scale 1:25,000, whereon all GSI 1980 seismic lines are located.
* Navigation tape for all seismic shot point locations.
* Seismic field tapes for all lines.


D09

GSI 80
AGC and WEM Processing Sequence
1. Demultiplex, gain recovery
2. Gain analysis, amplitude recovery 
3. 4800% CDP trace gather
4. Deconvolution 
5. Velocity analysis 
6. NMQ, mute
7. 4800% CDP stack 
8. Filter
      a. Window 0-1.5 seconds: 12--56 HZ
      b. Window 3.0-5.0 seconds: 8-32 HZ 
9. Data-dependent equalization
10. Film display, 48 tr/in horizontal, 2.5 in/sec vertical 
11. Wave equation migration
12. Film display, 48 tr/in horizontal, 2.5 in/sec vertical

GSI 80
Exhibit B
Offshore Eel River Basin
Point Arena Basin
Offshore Salinas Basin
Offshore Santa Maria Basin

Offshore Eel River Basin
Line No.	Mileage	
2
7.82
4
14.18
5
6.71
7
10.83
11
13.38
11A
10.83
18
5.84
24
15.19
25
16.26
26
16.79
27
16.76
28
6.34
28A
11.39
29
8.58
30
16.58
31
13.19
32
15.92
33B
13.64


Totals:	18 lines	220.23 mi


Point Arena Basin
Lire No.	Mileage	
35
8.56
36
31.91
37
31.38
38
4.49
39
10.05
40
11.45
41
30.79
42
10.33
43
10.94
44
10.7
45
10.73
46
10.86
47
17.99
48
6.7
49
11.56
50
8.84
51
9.45
52
8.68
53
8.2
54
8.81
55
8.82
56
5.58
57
6.84
58
5.1
59
4.96
60A
6.7
61
5.47


Totals:	27 lines	305.89 mi

Offshore Salinas Basin
Line No.	Mileage
62
20.63
63
19.11
64
16.12
65
10.32
66
10.45
67
6.84
68
7.6
69
13.41
69A
2.7
70
14.37
71
13.05
72
12.18
73
12.05
74
8.82
75
8.2
76
7.44
77
6.71
78
5.58
79
4.61
80
5.05


Totals:	20 lines	205.24 mi

Offshore Santa Maria Basin
Line No. Mileage
81
11.01
81A
18.49
82
14.61
82A
37.82
83
5.32
84
8.53
85
9.65
86
8.92
87A
6.65
88
11.93
88A
22.14
89
4.41
90
15.71
91
17.37
92
10.95
92A
6.09
93
19.55
94A
4.84
95
5.46
96
19.94
97
19.95
98
18.72
99
22.5
99A
20.7
100
19.2
101
6.42
102
13.39
103
18.86
104
18.12
105
13.23
106
19.43
107
9.91
107A
6.44
108A
14.85
109
9.93
109A
4.27
109E
16.9
110
9.89
111
11.86
112B
6.09
112C
9.53
113
4.05
113A
11.85
114
12.59
115
9.85
115A
4.71
116
12.81
117
12.88
118
12.26
119
10.92
120
11.01
121
9.57
122
9.18
123
9.55
124
6.36
125
7.09
126
6.34
127
5.3
128
5.19
129
8.56
130
9.03
131
7.52
132A
5.57
133
4.55
133A
4.07
134
7.95
135
7.07
136
5.15
137
9.55
138
6.12
139
6.03
140
7.62


Totals:   72 lines   799.90 mi
Totals, all basins:   137 lines  1,531.26 mi