Characterization of Seismically-Imaged Pennsylvanian Ooid Shoal Geometries and Comparison with Modern

Transcription

1 Characterization of Seismically-Imaged Pennsylvanian Ooid Shoal Geometries and Comparison with Modern W. Lynn Watney, Evan K. Franseen, Alan P. Byrnes, Rick Miller, and Abdelmoneam E. Raef Kansas Geological Survey The University of Kansas Lawrence, KS 6646 Stacy L. Reeder and Eugene C. Rankey Comparative Sedimentology Laboratory Rosenstiel School of Marine and Atmospheric Science, University of Miami Miami, FL 33149

2 Overview Thin (~4 m) Penn. 16 km x 3 km ooid shoal complex that encompasses two prominent stacked, high-frequency shoalingupward cycles. 4-D seismic (CO2 movement) suggests: Sinuous to linear, isolated pods, possible parabolic forms, oomoldic pore system and bed geometry variations appear to relate to amplitude patterns. structural lineaments that may have influenced the location of depositional and diagenetic lithofacies. Guided by seismic data, finer scale examination and integration of core, wireline log, and CO 2 flood data are refining geomodel. The resultant higher resolution subsurface picture of oolitic reservoir strata have geometries and facies distributions similar to individual oolitic shoal complexes in the Modern.

3 Lansing-Kansas City Oil Production Hall-Gurney Field

4 Dubois et al. (23)

5 Lansing-Kansas City Hall-Gurney Type Curve 4 th Order Sequences Heebner Toronto Ls Cass Ls (A) Stanton Ls (B) Plattsburg Ls (C) Farley/Argentine Ls (D) Iola Ls (G) 2-3 stacked 5 th order parasequences Dewey Ls (H) Cherryvale Fm (I) Dennis Ls (J) Swope Ls (K) Sniabar LS (L) 3 rd -order Sequence Set Thickness: 3-3 ft Porosity: -35% Permeability:.1-3md

6 1 cm ft, Layer 2 clean well sorted, cm-scale bedding, oomoldic Ø φ = 34.1% k = md low gamma ray Dubois et al. (23)

7 Synthetic Seismic Trace Base of Lansing & top of Kansas City Plattsburg LS 9 m 548 ms Porous zone 5 m thick Klauder 2-1 Hz Wavelet Heebner Shale Plattsburg Ls

8 Lineament attribute baseline data (prior to CO 2 injection) A strong correlation exists between the preferential movement of the CO 2 through this reservoir and features evident on the lineaments attribute map It appears lithology, especially rock properties, are preferentially influencing fluid movement through this reservoir Parallel progressive blanking of amplitude envelope, April 24 and June 26 showing CO 2 plume Instantaneous frequency at 56 msec with lineaments Color representation of amplitude values along the 56 msec time slice with lineaments displayed.

9 Attribute Analysis on Baseline Data Ø*ft map #1 CO2 I #1 Colliver #16 #18 Time structural map (red highs) Similarity seismic facies map white poorer reservoir properties NE-SW trend of more favorable reservoir properties Patterns of more favorable reservoir is lobate-shaped like porosity-ft map (Dubois et al., 23).25 mi (.4 km)

10 Gross Pay Plattsburg Limestone 2 Structural lineaments feet Structure Top Plattsburg Limestone CO2 Project feet -124 CO2 Project

11 COLLIVER (CO2) #16 - C-D GR.GAPI :G CNPOR.pu : DPOR.pu :D BVW Total Connected.3.2 Secondary RLL3.Ohm-m RILM.Ohm-m RILD.Ohm-m Depth Pay zone Plattsburg Ls Depth Depth GR Ø Sonic 291 2ndary Ø R Sw=4% Sw=6% Sw=8% Sw=1% POROSITY Sw=2% 1.1 BVW=.14 BVW=.12 BVW=.1 COLLIVER (CO2) #16 Ave. Neutron-Density Phi RESISTIVITY Ohm-m Clean GR Cap C-D Depth: X: Y: a: 1 m: 3.15 n: 2 RW:.472 GR.GAPI :G Murfin CO2-Colliver #16 Deepen, re-perforated Drilled April 23 Pay zone cored with full suite of wireline logs Upward increase in porosity Super Pickett pay zone clearly identified as low gamma ray zone with highest porosity and lowest water saturation Archie equation parameters: a =1, n= 2, m = 3.15

12 Colliver #16 core: Bedsets, grain size range Bed # vc c-m f-vf mud Bedset #2: 3-fining up, well sorted 1-coarsening up, well sorted 1-fining up, less well sorted Bedset #3: Top-coarse, well sorted Lower-poorly sorted w/bioclasts Bedset #4: Cap- well sorted Lower-Poorly sorted Thin bedsets Better sorted capping strata on bedsets Bedset #5: Top 3 cm thick beds w/biocl.caps Lower-micritic clasts, bioclasts, superficial oolite Small-scale beds noted as breaks Bedset #6: Poorly sorted, biocl., to marine wackest. Largest to smallest grain size

13 Colliver #16 core: Upward increasing in oomoldic content 2882 Bed # Dip Angle % Moldic vc c-m f-vf mud 2884 Depth (ft) Better sorted Bed # Dip Angle % Moldic Largest-smallest grain size

14 Colliver #16 Core/Log: Notably higher permeability toward top of Plattsburg Ls. and in cycle caps; relates to upward increase in porosity and Archie cementation exponent, m (more oomoldic and micro-vugs ) GR.GAPI :G core k max Porosity * better sorted cycle cap (layer #2) * fractures p * better sorted cycle cap (layer #4) Archie Cementation Exponent CNPOR.pu : DPOR.pu :D Core Analysis Archie m

15 K max (md) Gamma Ray (API) Clean (lower gamma ray), better-sorted oolite/ oomoldic Higher permeability, >1 md Correlation with: better sorting, packing, and interconnected oomolds (microvugs & associated high Archie cementation exponent) Porosity Clean, better sorted higher porosity in cycle caps and highest near top in shallowing upward succession Gamma Ray (API) Better sorted bar crests in Modern ooid shoals,

16 Porosity*Ft Map Stratigraphic Cross Section North-South #1 Datum: Base Plattsburg Limestone CO2 I #1 Colliver #16 Crosses CO 2 site and porosity development to south #18 Utilize color versions of uncalibrated gamma ray and neutron logs.5 Mile (.8 km) long.25 mi (.4 km)

17 CO2 plume projects into cross section in upper portion of porous, low GR Plattsburg Limestone between wells Clvr #1 and Clvr #18. North South North South Clvr7 Clvr1 Crtr5 Crtr1 Clvr1 Clvr18 Crtr11 Clvr7 Clvr18 Crtr5 Crtr1 Crtr11 CO 2 CO 2 No Horizontal scale Total length ~.5 mi. (.8 km) Datum: Base Plattsburg Limestone Index

18 Structure Contour Map, Top Plattsburg Limestone Gentle dip to northwest from high in southeast with stronger dip to north and southwest Sec 28 CO2 #1 Outline of CO2 plume Regional structural lineament Sec Local structural lineaments Sec 33 Sec 34 CI = 1 ft. 1 ft. (3 m)

19 Comparison of two stacked, highfrequency cycles Porosity thickness of upper Layer #2 1 1 Possible polygenic parabolic-shaped ooid shoals Roughly orthogonal trends paralleling structure lineaments Offset to west of underlying layer #4 CO2 movement along porous layer #2 #7 Frac? CO2 #1 CI = 1 ft (contours) Porosity thickness of lower Layer #4 1 ft. (3 m) 1 1 Isolated elongate ooid shoal developed sub-parallel to regional structural lineament No CO2 movement in lower layer #4 CO2 #1 CI =.5 ft. 1 ft. (3 m)

20 Comparison of porosity thickness with thickness of clean Gamma ray Possible polygenic, parabolicshaped ooid shoals Roughly orthogonal trends paralleling structure lineaments CO2 movement along porous layer #2 Porosity thickness of upper Layer #2 #7 Frac? CO2 #1 CI = 1 ft (contours) Isopach of clean, low GR, capping Layer # ft. (3 m) 6. Sec 28 Sec 27 NW and NE trends closely paralleling structural lineaments Thicker, cleaner carbonate, Core suggest better sorted, more permeable CO2 #1 Sec 33 Sec 34 CI =.5 ft. 1 ft. (3 m)

21 Comparison of porosity thickness of lower Layer #4 and thickness of clean, low gamma ray interval capping Layer #2 Close correspondence of location and NE-trend of low gamma interval of upper layer #2 and thick porous interval of lower layer #4 New NW-trend of clean GR in layer #2 not reflected in #4 Both trends closely parallel regional and local structural lineaments Possible inherited topography from buildup of #4 affecting #2 Isolated shoal in #4 may also reflect topography (concurrent movement) along regional structural lineament Isopach of clean, low GR, capping Layer #2 Sec 28 Sec 27 CO2 #1 Sec 33 Sec 34 CI =.5 ft. Porosity thickness of lower Layer #4 CO2 #1 CI =.5 ft ft. (3 m) ft. (3 m)

22 Similar parabolic forms (convex/concave) Similar scale of lobate forms In general terms, the best sorted sediments occur at the bar crests (as observed in analog ancient shoals in this study) Grain size may vary - coarsest may be in troughs or on crests Modern Analogs Can Help Little Bahama Bank North Oceanward North North Grand Cay Ooid sand shoal Ebb-dominated tidal flow Tidal Flood Delta (Abacos): Shoal crest well sorted and inner lobe less well sorted (seagrass covered area bankward of shoal crest North 5 m Shelfward Interpretive patterns of flow in an ebbdominated oolitic tidal bar. S. Reeder and G. Rankey (25) DigitalGlobe c

23 Conclusions 4D seismic and CO2 monitoring define new heterogeneities involving apparent structure and lithofacies variations. Accurate and precise characterization of connected (effective) oomoldic pores is critical in IOR modeling and prediction: Better sorted, cleaner (low GR), highly porous (>17%) oomoldic grainstone appear to be more permeable; In Plattsburg Limestone at Hall-Gurney Field, best sorting noted in upper portion of shallowing upward high frequency (5 th order) cycles and bedsets, probably delimiting separate ooid shoal development; Moldic porosity increases upward in shallowing bedsets and high frequency cycles; Archie cementation exponent, m, also increases upward, reflecting increased molds and microvug electrical behavior. Structural control likely at various scales and timing in formation of this ancient ooid shoal complex. Bi-directional cross stratification in stacked, shallowing upward bedsets suggest tidal influence. Geometries, scales, and facies distributions suggest analogs to Modern tidally influenced ooid complexes. Opportunity to define and predict geomorphic, granulometric, and petrophysical properties combining Modern and ancient oolitic systems.