[First Hit]

Datapages, Inc.Print this page

Hydrocarbon Play Types in the Tertiary Rocks of the Magallanes Basin, Chile, Revealed by Seismic Stratigraphy

 

Pigott, John D.1, Sara Elgueta2 (1) University of Oklahoma, Norman, OK (2) Sipetrol S. A, Santiago, Chile

 

The Magallanes Basin of Southern Chile is a polyhistory basin with three distinct episodes of geomechanical strain responses to tectonic stress: 1. An elastic pre-Cretaceous rifting stage, 2. A flexed downwarping and upwarping Turonian stage, and 3. A Tertiary vis­coelastic response to loading and unloading. These three geomechanical episodes have resulted in the evolution of a variety of possible petroleum systems with Previous HitverticalNext Hit, Previous HitlateralNext Hit, and mixed Previous HitverticalNext Hit-Previous HitlateralNext Hit Previous HitmigrationNext Hit pathways. Though the Chilean-Argentine Mesozoic petrole­um systems of the basin are still productive, most of the Magallanes Tertiary Foreland Basin remains unexplored. However, regional seismic stratigraphy integrated with borehole data and basin modeling of this largely frontier basin reveals seven distinct hydrocarbon play types for the Tertiary rocks:

1. Paleocene TST (“Zona Glauconítica”) on-lapping sands on an Eastern Turonian ramp of principally horizontal Previous HitmigrationNext Hit pathways. 2. Offlapping Oligo-Miocene LST deltas proxi­mal to deep faults for secondary Previous HitlateralNext Hit Previous HitmigrationNext Hit with viscoelastic deformation from origi­nal Previous HitverticalNext Hit elastic fault conduits from deeper strata. 3. Structurally rotated Oligo-Miocene deltas with secondary Previous HitmigrationNext Hit. 4. Basin floor fan channel sands with hydrocarbons feed­ing updip from viscoelastic deformation and basin floor fan feeder channels. 5. Sub decolle­ment folded and faulted Eocene basin floor sands of secondary Previous HitmigrationNext Hit. 6. Paleocene incised LST valleys filled by ensuing TST shales and sands of Lower Eocene upon a Turonian ramp with Previous HitlateralNext Hit Previous HitmigrationNext Hit upon a viscoelastic flexed basement flank. 7. Miocene HST flu­vial and estuarine channels associated with alluvial/estuarine complexes with Previous HitverticalTop migra­tion from deeper Cretaceous strata (eastern margin).