The Sedimentology, Stratigraphy and Reservoir Characteristics of the Montney D1 and D2 Horizons, Greater Pouce Coupe Area, Alberta and British Columbia

• Author / Creator

  Prenoslo, Donald

• The Middle Montney D1 and D2 Horizons in the Greater Pouce Coupe Area are important exploration targets. These moderate porosity and low permeability siltstone units have been referred to as distal shelf deposits in the past, based primarily on their restricted grain size. The D1 and D2 Horizons host a considerable volume of liquids rich natural gas. Considering this, a refined and robust interpretation of the paleodepositional setting and stratigraphic architecture of these units is crucial to facilitate exploration success. To achieve this objective, detailed sedimentological and ichnological data was recorded from 31 cores within an area of approximately 3200 km2. Geophysical logs from 1000 wells were analyzed to correlate important surfaces and to understand the distribution of the D1 and D2 Horizons throughout the study area. Additionally, XRF derived elemental compositions were used to confirm and refine sequence stratigraphic interpretations and were used as proxies to infer changes in D1 and D2 Horizons depositional processes. Eight distinct lithofacies are identified from the dataset. Lithofacies analyses indicate that the studied strata represent distal offshore to offshore-transition sedimentary environments. Linear sourced turbidity currents are thought to be the most important mechanism for sediment deposition. An arid coastline with numerous ephemeral river systems transported large volumes of sediment to the coast during storms. This may have created an over steepened shoreface / wave-dominated delta profile, which was prone to mass wasting events. Additionally, the study area was in a structurally complex setting, and as a result syn-depositional structural reactivations would have been equally likely to trigger mass wasting events. The D1-D2 transition is characterized by the presence of silty shale beds. The presence of appreciable amounts of clay in the Montney is rare except for a few areas. These areas are interpreted to have been deposited under the influence of perennial deltaic systems. During the D1-D2 transition silty shale beds indicate that there was a perennial river system running through the Hines Creek Graben sourcing clay. This work has contributed to the understanding of the sedimentology and the stratigraphic architecture of the Montney Formation in the Greater Pouce Coupe Area that will help decrease exploration risk. Ideally, the integration of detailed sedimentologic observations with regional mapping and geochemistry shown within this work will aid in other studies of the Montney Formation as well as in other unconventional plays around the world.

• Subjects / Keywords

  • Unconventional Resources
  • Stratigraphy
  • Sedimentology
  • Montney Formation

• Graduation date

  Fall 2016

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R38P5VQ1C

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.