Abstract
This study documents that Danian-aged sand remobilization of deep-water slope-channel complexes and intrusion of fluidized sand into hydraulically fractured slope mudstones of the Great Valley sequence, California, generated 400-m (1312 ft)–thick reservoir units: unit 1, parent unit channel complexes for shallower sandstone intrusions; unit 2, a moderate net-to-gross interval (0.19 sand) of sills with staggered, stepped, and multilayer geometries with well-developed lateral sandstone-body connectivity; unit 3, a low net-to-gross interval (0.08 sand) of exclusively high-angle dikes with good vertical connectivity; and unit 4, an interval of extrusive sandstone. Unit 2 was formed during a phase of fluidization that emplaced on an average 0.19 km3 (0.046 mi3) of sand per cubic kilometer of host sediment. Probe permeametry data reveal a positive relationship between sill thickness and permeability. Reservoir quality is reduced by the presence of fragments of host strata, such as the incorporation of large rafts of mudstone, which are formed by in-situ hydraulic fracturing during sand injection. Mudstone clasts and clay- and silt-size particles generated by intrusion-induced abrasion of the host strata reduce sandstone permeability in multilayer sills (70 md) when compared to that in staggered and stepped sills (586 and 1225 md, respectively). Post-injection cementation greatly reduces permeability in high-angle dikes (81 md). This architecturally based reservoir zonation and trends in reservoir characteristics in dikes and sills form a basis for quantitative reservoir modeling and can be used to support conceptual interpretations that infer injectite architecture in situations where sands in low net-to-gross intervals are anticipated to have well-developed lateral and vertical connectivity
Original language | English |
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Pages (from-to) | 309-343 |
Number of pages | 35 |
Journal | AAPG Bulletin |
Volume | 97 |
Issue number | 2 |
DOIs | |
Publication status | Published - Feb 2013 |
Bibliographical note
ACKNOWLEDGEMENTSThis study was conducted as part of the Sand Injectites Phase 2 at the University of Aberdeen, funded by Department of Energy and Climate Change (DECC) (formerly the UK Department of Trade and Industry), Dong, Lundin, Marathon, Statoil, and Total. We thank our colleagues in the Injected Sands Group for their support. The interpretations presented here are solely those of the authors. We thank Ian D. Bryant and two anonymous reviewers, and AAPG Editor, Stephen E. Laubach, for the peer-review comments that enhanced the manuscript. We also thank Frances P. Whitehurst for editing the final manuscript. We would like to thank Statoil U.K. and, in particular, Mariner Petroleum Technology, for financial support in the publication of this manuscript.
The AAPG Editor thanks the following reviewers for their work on this paper: Ian D. Bryant and two anonymous reviewers.
DATASHARE 46
Appendices 1–16 are accessible in electronic version on the AAPG Website (www.aapg.org/datashare) as Datashare 46.
Keywords
- sand injectites
- reservoir characterisation
- outcrop
- panoche hills
- moreno formation