stratigraphic architecture and facies analysis of the lower cretaceous dina member of the mannville

200 Pages·2012·7.91 MB·English

STRATIGRAPHIC ARCHITECTURE AND FACIES ANALYSIS OF THE LOWER
CRETACEOUS DINA MEMBER OF THE MANNVILLE GROUP IN NORTHWEST
SASKATCHEWAN

A Thesis
Submitted to the Faculty of Graduate Studies and Research
In Partial Fulfillment of the Requirements
For the Degree of
Master of Science
In Geology
University of Regina

By
Daniel Jonathon Kohlruss
Regina, Saskatchewan
October, 2012
Copyright 2012, D.J. Kohlruss
UNIVERSITY OF REGINA

FACULTY OF GRADUATE STUDIES AND RESEARCH

SUPERVISORY AND EXAMINING COMMITTEE

Daniel Jonathon Kohlruss, candidate for the degree of Master of Science in Geology, has
presented a thesis titled, Stratigraphic Architecture and Facies Analysis of the Lower
Cretaceous Dina Member of the Mannville Group in Northwest Saskatchewan, in an
oral examination held on October 5, 2012. The following committee members have found
the thesis acceptable in form and content, and that the candidate demonstrated
satisfactory knowledge of the subject material.

External Examiner: Dr. Steven Hubbard, University of Calgary

Co-Supervisor: Dr. Guoxiang Chi, Department of Geology

Co-Supervisor: Dr. Per Kent Pederson, Adjunct

Committee Member: Dr. Maria Velez Caicedo, Department of Geology

Chair of Defense: Dr. Renata Raina, Department of Chemistry & Biochemistry

*Not present at defense
ABSTRACT
Recent exploration activity in northwest Saskatchewan, north of the Clearwater
River Valley along the Alberta provincial border, has revealed an extensive bitumen
resource. 1.4 billion barrels to 2.3 billion barrels (222 million m3 to 371 million m3) of
bitumen is estimated in place. The bitumen-bearing sandstones belong to the Dina
Member of the Lower Cretaceous Mannville Group, stratigraphically equivalent to
Alberta’s McMurray Formation. The purpose of this study is to determine the
stratigraphic architecture of the Dina Member and its control on bitumen distribution in
the study area.
The Dina Member in northwest Saskatchewan was deposited unconformably on
top of the underlying Devonian Elk Point Group with the thickest Dina sandstones
residing within paleo-topographic lows on the unconformity surface. The Dina Member
was extensively eroded by Pleistocene glacial processes and is unconformably overlain
by Pleistocene glacial tills. Analysis of 83 stratigraphic test hole drill cores and 255
geophysical well log suites has revealed 8 recurring facies and 5 facies associations. The
facies are comprised of siliciclastic sediments, including sandstones, siltstones,
mudstones and in rare instances, coal. These facies are predominantly non-marine in
origin, including fluvial sediments and associated over-bank deposits. Many fluvial facies
exhibit a significant tidal and/or seasonal brackish water influence. Tidal indicators are
manifested as rhythmic grain size striping, reactivation surfaces and co- and back-flow
structures. Brackish conditions are indicated by impoverished, mono-specific
assemblages of diminutive trace fossils in mud beds and discrete sand layers, along with
marine palynmorphs and microfossils.
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Deposition of the Dina Member is interpreted to have occurred within an incised
valley system formed as a result of a relative base-level drop, which initiated trenching
and deepening of pre-existing valleys. Braided channel deposits proceeded to fill the
lowest portions of the valley during the lowstand and part of the subsequent
transgression. As the valley was gradually filled and the lateral accommodation space
increased, fluvial style changed from braided to meandering, with deposition of laterally
accreted point-bar deposits. These manifest as inclined stratification (IS) and inclined
heterolithic stratification (IHS) overlying basal trough cross-bed sets. Mud filled, oxbow
lake deposits were also observed in close association with the point-bar deposits.
Bitumen distribution throughout the study area is not uniform and has several
controls. Bitumen saturation is highest where braided fluvial and IS deposits are found,
especially when stacked. Conversely, IHS deposits and mud filled oxbow lake deposits
restrict oil flow and in cases act as flow barriers to oil migration. Bitumen is trapped
laterally by the incised valley walls created by the sub-Cretaceous unconformity, where
bitumen saturated sand pinches out against the impermeable carbonates. The Dina
sandstones, in turn, were sealed above by shales of the Clearwater Formation/ Cummings
Member of the Mannville Group.

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ACKNOWLEDGEMENTS
Funding for a large portion of this project was provided by the Saskatchewan
Ministry of Energy and Resources, most notably was a grant to Dr. Guoxiang Chi and Dr.
Per Kent Pedersen at the University of Regina.
Many individuals have contributed to this thesis in many different ways, through
technical support, inspiration and motivation. I would like to thank Dr. Guoxiang Chi and
Dr. Per Kent Pedersen for their technical support, patience and the freedom to think,
work and act independently throughout the process. Their many hours of editing and
valuable feedback are greatly appreciated.
I’d like to thank all my colleagues at the Ministry of Energy and Resources,
specifically, Arden Marsh, for his technical expertise with data management and mapping
software, as well for our many discussions surrounding sedimentology and stratigraphy.
I’d also like to thank Melinda Yurkowski who always believed I would finish this project
and provided the time needed to accomplish my goal. I’d also like to thank Jeff Coolican,
who “took-up-the-slack” in our shared work duties, while I focused on research. I’d like
to thank Gavin Jensen and Arden Marsh for their assistance preparing for our Clearwater
field season as well their time and energy while in the field. I’d also like to thank Megan
Love and Tyler Music, who provided technical support while assembling my thesis.

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DEDICATION

I would like to dedicate this thesis to my two children. Without them I would not
have the patience, maturity or strength to accomplish a goal of this magnitude. They
teach me more than I will ever be able to teach them and they make me a better person.
My son Ethan is the strongest individual I know and whenever I feel I can not
accomplish a goal, I look to him for motivation. He truly is my hero and I am blessed to
be his dad.
My daughter Avery inspires me every day with her beautiful personality, endless
curiosity and love of rocks and dogs. She makes me feel privileged to have the career
I’ve chosen and appreciate every day I am a geologist. I look forward to working with her
someday.
Finally, I owe a very special thanks and dedication to my wife Melanie, who
provided endless love, patience, encouragement and inspiration. She is always there when
I need her most and without her I would not have attempted, let alone finished this thesis.

“If you want to take the island, burn the boats!” –Tony Robbins

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TABLE OF CONTENTS
ABSTRACT……………………………………………………………………………… I
ACKNOWLEDGEMENTS...…………………………………………………………... III
DEDICATION.……………………………………………………………...………….. IV
TABLE OF CONTENTS…………………………………………………………………V
LIST OF TABLES……………………………………………………………………..VIII
LIST OF FIGURES……………………………………………………………………...IX
1. INTRODUCTION ......................................................................................................... 1
1.1 Purpose and Objectives ........................................................................................ 3
1.2 Previous Work ...................................................................................................... 5
1.3 A Review of Estuary Depositional Models .......................................................... 8
1.3.1 Introduction ................................................................................................... 8
1.3.2 Physical Processes ........................................................................................ 9
1.3.2.1 River and Tidal Currents ......................................................................... 11
1.3.3 Chemical Processes and Water Circulation ................................................ 13
1.3.4 Biological Processes ................................................................................... 15
1.3.5 Morphology................................................................................................. 16
1.3.6 Cross-Bedding and Tidal Indicators ........................................................... 18
1.3.7 Grain Size Distribution ............................................................................... 19
1.3.8 Estuarine Depositional Model..................................................................... 21
1.4 Study Area .......................................................................................................... 22
1.5 Study Methods.................................................................................................... 22
1.5.1 Net Pay and Net Water/Lean Mapping ....................................................... 25
1.5.2 Geological Isopach and Structure Maps ..................................................... 26
1.5.3 Geological Cross-Sections .......................................................................... 27
2. GEOLOGICAL SETTING .......................................................................................... 28
2.1 Regional Geology ............................................................................................... 28
2.2 McMurray Sub-Basin ......................................................................................... 36
3 FACIES DESCRIPTIONS AND DEPOSITIONAL INTERPRETATIONS ........... 41
3.1 Introduction ........................................................................................................ 41
3.2 Facies Descriptions and Interpretations ............................................................. 41
3.2.1 Facies 1: Massive Sandstone ...................................................................... 41
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3.2.2 Facies 2: Ripple Cross laminated Sandstone .............................................. 46
3.2.3 Facies 3: Planar Cross-bedded Sandstone ................................................... 48
3.2.4 Facies 4: Trough Cross-Bedded Sandstone ................................................ 54
3.2.4.1 Facies 4a: Medium to Very Coarse Trough Cross-Bedded Sandstone ... 54
3.2.4.2 Facies 4b: Massive to Trough Cross-Bedded Pebbly Sandstone ............ 59
3.2.5 Facies 5: Pebble Conglomerate ................................................................... 62
3.2.6 Facies 6: Inter-bedded Sandstone and Bioturbated Mudstone .................... 65
3.2.7 Facies 7: Siltstone, Mudstone, and Coal ..................................................... 73
3.2.8 Facies 8: Laminated Siltstone to Very Fine Sandstone .............................. 77
3.3 Facies Associations ............................................................................................ 80
3.3.1 Facies Association 1: Braided Fluvial Channel .......................................... 80
3.3.2 Facies Association 2: Tidally Influenced Meander Channel Deposits ...... 88
3.3.3 Facies Association 3: Oxbow Lake Fill ...................................................... 99
3.3.4 Facies Association 4: Flood Plain Crevasse Splay ................................... 102
3.3.5 Facies Association 5: Floodplain Deposits ............................................... 105
4. STRATIGRAPHIC ARCHITECTURE AND DEPOSITIONAL MODEL .............. 109
4.1 Introduction ...................................................................................................... 109
4.2 Structural and Isopach Maps ............................................................................ 109
4.3 Facies Association Structural Cross-Sections .................................................. 115
4.3.1 Cross-section A-A’ ................................................................................... 116
4.3.2 Cross-section B-B’ .................................................................................... 119
4.3.3 Cross-section C-C’ .................................................................................... 121
4.3.4 Cross-section D-D’ ................................................................................... 123
4.3.5 Cross-section E-E’ .................................................................................... 126
4.3.6 Cross-section F-F’ ..................................................................................... 128
4.4 Depositional Model .......................................................................................... 131
5. BITUMEN DISTRIBUTION ................................................................................. 137
5.1 Introduction ...................................................................................................... 137
5.2 Bitumen Distribution ........................................................................................ 137
5.3 Trapping and Bitumen Distribution Controls................................................... 149
6. CONCLUSIONS..................................................................................................... 156

LIST OF REFERENCES.………………………………………………………………158
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APPENDIX I : Formation and Facies Association Tops..………………………….….168
APPENDIX II : Bitumen Saturation Calculations….………………………………….177
APPENDIX III : Palynological Report..………………………………………..………185

VII
LIST OF TABLES

Table 3.1 Summary of facies within study area....………………………………………43
Table 3.2 Description interpretation and sequence stratigraphic nomenclature of facies
associations in the study area………………….…………………………………………81

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