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Stratigraphy and Petroleum Production Potential of the Spearfish Formation in North Central North Dakota Nnaemeka C

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Stratigraphy and Petroleum Production Potential of the Spearfish Formation in North Central North Dakota Nnaemeka C University of North Dakota UND Scholarly Commons Theses and Dissertations Theses, Dissertations, and Senior Projects 2011 Stratigraphy and Petroleum Production potential of the Spearfish Formation in North Central North Dakota Nnaemeka C. Anyanwu University of North Dakota Follow this and additional works at: https://commons.und.edu/theses Part of the Geology Commons Recommended Citation Anyanwu, Nnaemeka C., "Stratigraphy and Petroleum Production potential of the Spearfish Formation in North Central North Dakota" (2011). Theses and Dissertations. 6. https://commons.und.edu/theses/6 This Thesis is brought to you for free and open access by the Theses, Dissertations, and Senior Projects at UND Scholarly Commons. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of UND Scholarly Commons. For more information, please contact [email protected]. ,I STRATIGRAPHY AND PETROLEUM PRODUCTION POTENTIAL OF THE SPEARFISH FORMATION IN NORTH CENTRAL NORTH DAKOTA by Nnaemeka C. Anyanwu Bachelor of Science; Federal University of Technology Nigeria, 2006 A Thesis Submitted to the Graduate Faculty of the University of North Dakota in partial fulfillment of the requirements for the degree of Master of Science Grand Forks, North Dakota December 2011 1 ~ i This thesis, submitted by Nnaemeka C. Anyanwu in partial fulfillment of the requirements for the Degree of Master of Science from the University of North Dakota, has been read by the Faculty Advisory Committee under whom the work has been done and is hereby approved. · 1 (Chairperson) ~~~~(J--- J This thesis meets the standards for appearance, conforms to the style and format requirements of the Graduate School of the University of North Dakota, and is hereby approved . ..~ J-- a{J - , >= Date 11 ·- PERMISSION Title Stratigraphy and Petroleum Production Potential of the Spearfish Formation in North Central North Dakota Department Geology Degree Master of Science In presenting this thesis in partial fulfillment of the requirements for a graduate degree from the University of North Dakota, I agree that the library of this University shall make it freely available for inspection. I further agree that permission for extensive copying for scholarly purposes may be granted by the professor who supervised my thesis work or, in his absence, by the chairperson of the department or the dean of the Graduate School. It is understood that any copying or publication or other use of this thesis of part thereof for financial gain shall not be allowed without my written permission. It is also understood that due recognition shall be given to me and to the University of North Dakota in any scholarly use which may be made of any material in my thesis. Signature__ ~--,~-------- Date-----I.,---'--~-------- \ dJ l"DI ~DI I 111 TABLE OF CONTENTS LIST OF FIGURES .............................................. .......... ................. ....................... .. .......... vi LIST OF TABLES ............................. ......................... ............ .... .. .................................... vii ACKNOWLEDGMENTS ...................... ............................................. .. .......................... viii ABSTRACT .....................................................................: ................ ................................ .ix CHAPTER I. INTRODUCTION ... .............. ............................................................................... 1 General .. ................................. ...................................... ................................ l Purpose .............................................. ....... .... .......... ............ .................. .... ... 2 Regional Setting and Area of Study .......... .. ............... ................................. 2 Methods ..... ........................... .. ....................................................... ............ .. 2 II. STRATIGRAPHY AND LITHOLOGIC DESCRIPTIONS ....... .... .. .... ............... 5 Members of the Spearfish Formation ...... .......................... .......................... 5 Belfield Member .................................. .. .................... ................ ... ............... 6 Pine Salt Member ..... .. ......... ... ................ ...... ............................................... 6 Saude Member ................. ....... ................................................... ................ 10 Units Overlying the Spearfish Formation .................................................. 13 Stratigraphic Relationships and Correlations ............................................ 14 III. STRUCTURAL FEATURES ........... .... .. .... ...... ....... .... .. ....... .............................. 18 Nessen Anticline ....... .......................... .. ...... ... .. ........ .................................. 18 lV Cedar Creek Anticline .... .. ..... .. .. .... , ................................... .. ............... .. .. ... 19 Bowman Low .. ................. .................................. ............... .... .... ................. 19 Golden Valley Low. ..................... ;. ............ ....................... : ........................ 20 Stark High ......... .... ..... .... .. ... ... .............. ... .. ......... .... ................ .. ..... .... ......... 20 Mercer High ................................. .............. .. ....... ................................ .. ..... 20 IV. PETROLEUM POTENTIAL .......................................... ....... ............................ 22 Production Data ......... ................ .. .. ... ............... .... ............. ....................... .. 24 V. CONCLUSIONS ........................................... .. ....................... ............ .... ............ 28 Appendix A. Names and Locations of Wells Used in This Study ....... .. ....................... 30 Appendix B. Tabular Production Data .... :.. ..... ............................. .. .. .. .. ......................... 32 REFERENCES CITED ................ ................................. ........ .. .......................................... 47 V LIST OF FIGURES Figure Page 1. The four main oil fields of Spearfish Oil ................................................................. 3 2. Williston Basin stratigraphic colurnn ......................... ...................... ........................ 7 3. Isopach map of the Spearfish Formation ................................................................. 8 4. Typical electric log showing members of the Spearfish Formation ......... ......... ...... 9 5. 1$opach map of the Saude Member, Spearfish Formation in North Dakota .......... 12 6. Isopach map of the Pine Salt Member, Spearfish Formation in North Dakota .... .12 7. Isopach map of the Belfield Member, Spearfish Formation in North Dakota ...... .13 8. Typical decline curve .................................................. .... ....................................... 27 Vl LIST OFTABLES Table Page 1. Comparison of Spearfish Histories for ND and MB .. .. .. .. ................... ................ 32 2. Comparison of EUR for ND and MB ........................... ...... .. .............................. 35 3. Comparison of EUR Vertical vs Horizontal .. .. ..................................... ..............38 4. Normalized Production Vertical vs Horizontal.. .................. .. .. .......................... 41 5. Normalized Production ND vs MB ........ .......................... .. .. .......... ..................... 44 Vll ACKNOWLEDGEMENTS I would like to thank my committee members, Drs. Richard D. Lefever (chairman), Nels Forsman, and Zeng, Zheng-Wen, for their advice and critical reviews of the thesis and advice during research. I would especially like to thank Dr. Lefever for his constant encouragement and support. Thanks are also extended to the North Dakota Geological Survey for the use of their facilities at the Wilson M. Laird Core library at the University of North Dakota, Grand Forks, North Dakota. I would like to thank my family, friends and fellow graduate students for their support, encouragement, and understanding during my graduate studies. Vlll ABSTRACT The Spearfish oil play is unconventional requiring the use of horizontal wells that are fracture stimulated to deliver economic flow rates. However, fraccing into the underlying water has been a source of significant production problems for operators. The key to developing the area is to keep the individual fracs large enough to stimulate the tight Spearfish sands but not to let them propagate into the underlying water zone. The Spearfish Formation of the Black Hills has been traced into the subsurface of the Williston Basin in western North Dakota from bore holes at the northern margin of the outcrop area in extreme eastern Wyoming. In the Williston Basin, the Spearfish can be divided into three lithologic units; in ascending order these are; a lower gray shale and red siltstone unit (Belfield Member), a middle salt unit (Pine Salt Member) and an upper siltstone unit (Saude Member). The lower two units are considered to be Permian, while the overlying Saude Member is predominantly Triassic. In North Dakota, the Saude is considered to be an onlapping transgressive unit, probably supplied by a source area to the west and becoming younger to the east and north where it rests with angular discordance on progressively older Paleozoic rocks. Lack of fossil evidence makes it difficult to assign a definite age to the upper part of
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