MULTICOMPONENT SEISMIC ANALYSIS OF THE ROADRUNNER/TOWAOC AREA OF THE PARADOX BASIN, UTE MOUNTAIN UTE RESERVATION, COLORADO Photo by C. Rebne Paul La Pointe, Golder Associates Claudia Rebne, Legacy Energy Steve Dobbs, Red Willow Production Colby VanDenburg, Red Willow Production Tom Davis, CSM Processing by WesternGeco & GMGAxis Acquisition by SolidState (Grant) & Baker-Hughes

Major Funding came from the U. S. Dept. of Energy, National Energy Technology Laboratory, & Red Willow Production whose financial support is gratefully acknowledged. “This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof” “For entertainment purposes only”

Project Location DOE Shoot – 3D9C Northwest Extension – P wave

Lithostratigraphy & Seismic Picks

P- Wave Interpretation Two vendors and three versions for processing WesternGeco carried out two processing versions, W1 & W2 W1 uses Random Noise Attenuation W2 no RNA, instead, Spectral Whitening GMGAxis produced P-Wave volume as part of anisotropy analysis.

W1 – Random Noise Attenuation Ismay – Desert Creek Isochron

W2 – Spectral Whitening Ismay – Desert Creek Isochron

GMGAxis Ismay – Desert Creek Isochron

Which Processing to Choose? We looked at non-parametric correlations and univariate regressions to see which processing picks corresponded best with lithostratigraphic horizons and isopachs as picked from well logs. We looked at a host of variables: seismic picks and isochrons; lithostratigraphic picks and isopachs; production variables. The Western 1 processing had the best predictive power for the lithostratigraphy.

An Example Regression Ismay – Desert Creek isopach thickness vs. Ismay – Desert Creek isochron regression, WesternGeco 1.

A first series of lithostratigraphic maps were produced using the W1 regressions Ismay Peak - Desert Creek Peak Isochron Map

Another series of maps were produced using multivariate regressions informed by PCA Factors 1, 2 and 4 are most significant for the regression concerning the stratigraphic thickness from the Ismay to the Desert Creek. Loadings for Factor 1 are negative, and for factors 2 and 4 it is positive. This means that the stratigraphic interval thickens when the depth to the Desert Creek datum is shallower, the interval below the Desert Creek to the Mississippian is thicker, and the Ismay to Desert Creek isochron is thickest Predicted Y IS_DC

Ismay Peak - Desert Creek Peak Isochron Map Multivariate Regression Map – Is it any better?

To answer this question, the real issue is not that one method or the other predicts lithostratigraphy, but whether it predicts productivity Predicted Y EUR_BOE On first glance, the statistical analysis says that seismic variables do a poor job of predicting total EUR. But a closer look reveals more promise.

The Upper Trend group has a much thicker anhydrite section and a thicker section between the top of the Ismay and the Upper Ismay carbonate. Also, the wells belonging to the Upper Trend group have much higher productivity, but oddly, lower net pay. There are actually two trends

Descriptive Statistical Summaries for the 2 Trends

In summary, we have been doing both conventional interpretation and a bit of statistical torturing to the P- Wave data, and are seeing some interesting results. Rich Van Dok of WesternGeco will review the just- finished PS and SS wave processing

D.O.E. Roadrunner 3D/9C for Red Willow Production Co. & Golder Associates DOE Award Number: DE-FG26-02NT15451 Processing Update – CSM RCP Meeting March 17, 2005 Rich Van Dok, Guillermo Caro WesternGeco - Denver

Survey Location 3D/9C Seismic Survey

Source and Receiver Locations S-wave Survey RECEIVER LINES SOURCE LINES GEOPHONE ORIENTATION S-WAVE SOURCE ORIENTATION* * OCCASIONALLY REVERSED DEPENDING ON DIRECTION OF TRUCK

Summary P-wave processing –Conventional KPSTM flow (azimuthally isotropic) PS-wave processing –CCP binning/post-stack time migration –Limited-azimuth volumes Azimuthal anisotropy (splitting) analysis SS-wave processing –Sh-Sh for statics and velocity –Azimuthal anisotropy (splitting) analysis

Typical Shot Record: P source – Z detector

Brute Stack: P source – Vertical component

DMO Stack: P source – Vertical component

Final Migration: P source – Vertical component Displayed at final datum

WesternGeco P-wave Data Version 1 Inline 1104 SouthNorth Ismay Desert Creek

WesternGeco P-wave Data Version 1 Ismay - Desert Creek Isochron (Red = 25 ms, Blue = 20 ms) Inline 1104

Typical Shot Record: P source – Radial component

Typical Shot Record: P source – Transverse component

Brute Stack: P source – Radial component

Final Migration/FXY Dcn: P source – Radial component

Final Migration Comparison: PP to PS

R T N N0ºE N45ºE N90ºE N135ºE N270ºE N180ºE N225ºE N315ºE Source to Receiver Azimuth Limitation

PS Input to 2Cx2C Layer Stripping RADIAL COMPONENT (0º-360º)TRANSVERSE COMPONENT (0º-360º) LAYER 1 LAYER 2

S-wave Birefringence: Layer 1

S-wave Birefringence: Layer 2

Shot Record: Trans source – Trans detector Component used for initial statics and velocity work

Source and Receiver Static Corrections S-WAVEP-WAVE

Comments/Conclusions P-wave amplitudes show algal mound structure PS-wave resolution very good –General event calibration good –Algal mound structure apparent PS-wave azimuthal anisotropy analysis shows small, but measurable effect –Possible correlation to general structure in overburden (?) –Reservoir level shows little anisotropy SS-wave refraction statics solution resonable compared to PP