1 / 21

210 likes | 406 Vues

A Second Look at the Fluid Factor. Based on UH Dissertation by Dr. Jenny Zhou – Former AGL RA. Quantifying Seismic Reflectivity. Fred Hilterman Distinguished Research Professor – University of Houston Chief Scientist – Geokinetics Data Processing and Interpretation April 28, 2010.

Télécharger la présentation
## Quantifying Seismic Reflectivity

**An Image/Link below is provided (as is) to download presentation**
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.
Content is provided to you AS IS for your information and personal use only.
Download presentation by click this link.
While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

**A Second Look at the Fluid Factor**Based on UH Dissertation by Dr. Jenny Zhou – Former AGL RA QuantifyingSeismicReflectivity Fred Hilterman Distinguished Research Professor – University of Houston Chief Scientist – Geokinetics Data Processing and Interpretation April 28, 2010**Birth of Fluid Factor**George Smith & Maurice Gidlow South Africa - 1986**Smith and Gidlow; Fatti et al.**Generate NIP and NIS from AVO inversion RC() NIP/cos2() – 2 NIS sin2() NIP = P-wave normal incidence NIS = S-wave normal incidence Fluid Factor Review Class 1 AVO 2.9 Stack 3.0**NIS**NIP Fluid Factor: F = NIP - NIS Fluid Factor Review Class 1 AVO 2.9 Stack 3.0 2.9 NIP 3.0 Brine saturated: F = 0 Gas Saturated: F = NIPGAS- NIPWET 2.9 NIS 3.0**Can F discriminate oil from gas ?**Fluid Factor Review 2.9 Stack 3.0 2.9 Gas Oil NIP - 0.56 NIS 3.0**Calibrating Fluid Factor to**Well-Log Data**Regression Equations**NIOIL = -0.052 + 1.09 NIWET R2 = .94 NIGAS = -0.088 + 1.14 NIWET R2 = .83 NIOIL - 1.09 NIWET = - 0.052 NIGAS - 1.14 NIWET = - 0.088 Fluid Factor from Normal Incidence 151 wells from South Marsh Island (NIGAS-NIWET) Wet Oil Gas NIHYDROCARBON-NIWET Fluid Factor NI varies significantly for gas- and brine-saturated sand… but (NIGAS-NIWET) changes little. Reservoir porosity: 10-33 % Encasing shale: 2600-4200 m/s How is Fluid Factor extracted from seismic data?**Based on horizon pore-fluid projection**F(t) ≡ NIP(t) – 0.72 NIS(t) + 0.03 therefore … E{FWET} = 0 Gas Oil Wet Linear Equation NIP=0.72NIS-0.03 Wet Oil Gas Fluid Factor = NIP - 0.072NIS + 0.03 Fluid Factor from NIP & NIS F(t) ≡ NIP(t) - NIS(t) (Smith and Gidlow) F 0 In wet zones F (NIP,GAS-NIP,WET) At top of reservoir 151 wells in South Marsh Island**Unique Properties of**Fluid Factor**R**R R S S S Shale Shale Gas Sand Gas Sand Wet Sand Wet Sand NIGAS NIWET F - NIGWC (AIWET SAND–AIGAS SAND) (AIWET SAND+AIGAS SAND) NIGWC = Fluid Factor: Boundary or Layer Property? NIGAS – NIWET = F - - F relates to gas/water contact -NIGWC … not encasing shale.**Fluid Factor: 9-m Wet Thin Bed**VP = 2280 m/s VP = 2280 m/s VP= 2250 m/s VP = 3600 m/s VP = 3490 m/s VP = 2280 m/s NIP NIS F Seismic Section: Fluid Factor = NIP – 0.55 NIS**Fluid Factor: 9-m Gas Thin Bed**Two-way time Two-way time 11.1 ms 5.3 ms F Seismic Section: Fluid Factor = NIP – 0.55 NIS 109% increase in two-way time VP = 2280 m/s VP = 2280 m/s VP= 1628 m/s VP = 3370 m/s VP = 3490 m/s VP = 2280 m/s NIP NIS Approximately 109% increase in amplitude**Thin Bed: Fluid Factor vs. NI**Fluid Factor Wet ……..… F = 0 * 2 t/T Oil, Fizz…… F = -.058 * 2 t/T Gas ……….. F = -.088 * 2 t/T Normal-Incident Reflectivity NI = f( VP1, VP2, Rho1, Rho2) * 2 t/T t = thin-bed traveltime T = wavelet period • Fluid factor independent: • shale properties • reservoir porosity • upper shale lower shale**Oil**Gas 1 s 2 s -3000 m 3 s 7.5 km GOM Oil and Gas Reservoir Reservoir exhibits fault shadow velocity anomaly Well Production: Early 1970s Seismic Data: 1996 as OBS Seismic Processing: 2008 Seismic data from Fairfield Industry, Inc.**Producing oil well**Abandoned oil well Producing gas well AVO Inversion –NIP & NIS Seismic NIP Seismic NIS 400 1500 WET WET 4.2 miles 0 -200 -1500 -800 Fault Fault 4.6 miles Zhou 2009**Producing oil well**Abandoned oil well Producing gas well Fluid-Factor Projection Line Calibrated Fluid Factor NIP(2)=0.3266 NIS(2)+0.0022 R2=0.8408 NIP = 0.33 NIS + .002 R2 = 0.84 0.02 0 Calibrated NIP -0.04 Fault Wet area Whole survey -0.08 Fluid Factor = NIP -.33 NIS - .002 Calibrated NIS Zhou 2009**Fluid Factor Prediction of Pore Fluid**Depth Contours Wet sand - 0.02 2 3 Oil sand 4 1 6 5 - 0.066 7 9900 10 9 Fault Gas sand 8 Fluid Factor Producing oil well Abandoned oil well Producing gas well 3 producing wells correctly located Gas zone correctly located Gas and oil zones generally tie depth contours Calibrated fluid factor is an accurate pore-fluid discriminator. Zhou 2009**Summary: Fluid-Factor Properties**• … independent of shale properties above or below reservoir. • … independent of reservoir porosity. 3. … independent of wavelet shape. 4. … related to NI of hydrocarbon/water contact. 5. … function of thin-bed traveltime and pore fluid.**Field Study Conclusions**• NIP vs. NIS horizon crossplot provides • … E{FWET} = 0. 2. Regional well-log curves provide … Seismic to well-log amplitude calibration. 3. With questionable wavelet and low-frequency control, F was better pore-fluid discriminator than PI or .

More Related