I. SUMMARY

SEI Offshore Division offers to the industry an innovative approach to the Texas Mid-Dip Miocene area. Our survey area
has been overlooked by the industry for 3D data due to the perceived lack of sands. However, recent information is causing
clients to reconsider exploration targets in this area. 

Our Texas Mid-Dip Miocene 2D Recon Survey utilized 9,000 meters of offset in our acquisition and digital well log information furnished by GDC for pre-stack time migrated and AVO parameters. 

II. SURVEY SIZE

3730 Linear Miles

III. CONTRACTOR

Fugro - Geoteam

IV. ACQUISITION PARAMETERS
 

Recording System	I/O MSX 24 bit
Recording Filter	Low 2 Hz / 375 Hz
Sample Rate	2 ms
Record Length	10.5 seconds
Airgun Array	3660 cubic inches
Bar Meters	155.5 peak-peak, I/O MXS filters
Streamer	I/O MSX digital
Streamer Length	9000 meters
Receiver Interval	12.5 meters
Total Receivers	720 traces
Source Interval	50 meters
Fold	90

Strike Information
 

Strike Lines	20
Line Spacing	1.75 miles
Maximum Line Length	225.12 miles

Dip Information
 

Dip Lines	12
Line Spacing	Approx. 15 miles
Line Lengths	34.95 miles / 69.83 miles
Line Total	3780.46 miles

V. PROCESSING FLOW

UKOOA P1 / 90 navigation merge
Reformat, resample to 4 msec. length = 10.5 sec.
Common offset bin to 45 uniform offsets, CDP interval = 12.5 meters, differential moveout applied
Spherical divergence correction
Q compensation
Spiking deconvolution followed by deterministic filter to convert the data to zero phase 
Velocity analysis every two miles with offset limited to offset = depth
Anisotropy analysis
FX decon noise rejection in common-offset domain
NMO with anisotropice NMO every one mile
DMO
Migration before stack (MBS)
Velocity analysis with anisotropic NMO every one mile
Radon transform multiple rejection
Fine-tune velocity analysis with anisotropic NMO; NMO-corrected gather display at every one-half mile
Generation of MBS stacks (RAP and structural)
Generation of AVO products on tape
            Normal incidence reflectivity - NI
            Poisson reflectivity - PR
            Three common-angle stacks
            CDP gathers
AVO color cross plot of NI vs. PR for dip lines (most likely on tape)

VI. Deliverables

Seismic Data Processing and Petrophysical Analyses

1.    For all dip and strike lines
        1.    MBS stacks - SEGY tape
        2.    Normal incidence (NI) reflectivity stacks - SEGY tape
        3.    Poisson reflectivity (PR) stacks - SEGY tape
        4.    Near-, mid-, and far-angle stacks - SEGY tape
        5.    CDP gathers - SEGY tape

2.     For dip lines
        70 mile: D6, D12, D18, and D24
        35 mile: D16, D20, and D26
 

1.

AVO color cross plot of NI vs. PR - SEGY tape  The digital traces for these files will be encoded with numbers 1-144 (or appropriate numbers for scaling by Landmark systems) that represent the NI and PR position in the two-dimensional color cross plot matrix table. An additional file will be delivered that assigns colors to the numbers in the traces. This will allow the AVO color cross plot to be displayed as a conventional Landmark (GeoQuest) product.

2.

Seismic calibration and petrophysical analyses 1.    Seismic Signature Book* for 20 (minimum) tie wells - hard copy 2.    ID synthetic seismograms and well log curves in time - SEGY format

3.

ID Synthetics 6.    Sonic/density in-situ properties 7.    Sonic/density fluid replacement properties 8.    Resistivity in-situ

4.

2D AVO Synthetics 9.    Total AVO with offsets 0 - 9000 meters - in-situ 10.    Total AVO with offsets 0 - 9000 meters - in-situ 11.    AVO Petrophysical Components (3) - in-situ 12.    AVO Petrophysical Components (3) - fluid replacement

5.

Velocity/density trend plots of sand and shale

6.

Poisson's Ratio and Ln (Acoustic Impedance) Histogram plots for sand and shale overlain

7.

Cross plot of Poisson's Ratio and Ln (Acoustic Impedance) for depth interval of interest

8.

Seismic CDP gather near well location

Optional Products
 

9.

Top of geopressure time horizon for each seismic line - tape

10.

Time-depth velocity file for each seismic line - tape

11.

AVO color cross plot of NI vs. PR for any seismic line - hard copy or tape

12.

Digital petrophysical attribute file (approximately 40 attributes) derived from offshore Texas wells at 200 foot increments

13.

Sand/shale trend analyses based on paleo, geopressure, depth, and other constraints

14.

Digital synthetics for other offshore Texas wells