Reservior characterization of West Waha and Worsham-Bayer Fields

Southeastern Delaware Basin, West Texas Using integrated data source

Masterarbeit , 2010 , 185 Seiten , Note: 700

Geowissenschaften / Geographie - Geologie, Mineralogie, Bodenkunde

West Waha and Worsham-Bayer fields are located in the Southeastern Delaware Basin, West Texas. For several decades, these fields have been experiencing problem of low natural gas recovery in contrast to their large estimated reserves. This study involved the integration of interpreted three data sets namely; 10 well logs, 20-sq- miles 3D seismic and production data. The principal objectives for this study were to determine the impact of thin-beds on reservoir petrophysical analysis and to assess the impact of estimated recoverable reserve on the interpreted reservoirs (R1 [Lower Ordovician Ellenburger group], R2 [Silurian Fusselman formation], R3 [Devonian Thirtyone Formation] and R4 [Undifferentiated Mississippian Limestone].
Reservoir characterization method employed were: well log correlation, petrophysical analysis to calculate porosity and Movable Hydrocarbon Index (MHI), reservoir attribute analysis for thickness estimation, seismic-to- well ties to detect the reservoirs of interest, fault mapping, 3D seismic interpretation, generation of time-depth structure maps for prospect mapping, volumetric analysis for recoverable reserve estimation and production record interpretation.
Well log correlation revealed complex thrust faulting, structural rotation and left- lateral strike-slip which serves as major traps in some areas of the fields. The reservoirs were thickening to Northeastern direction towards Texas arch and thinning Northwestern and the log motifs depict carbonate depositional environment type. The mean porosities for R1, R2, R3 and R4 reservoirs are 23.7%, 16.3%, 26.1% and 26.0% respectively, while the fields' mean porosity value is 23.1% showing excellent porosity value for natural gas flow. Wells 29, 36, 37 and 38 have MHI of >20%. R1 reservoir had the highest thickness value (146 ft) at well log 29. F1 and F2 are major faults and F3, F4, F5, F6, F7 and F8 and F9 are minor faults. F3, F2, F4, F5, F6, F7 and F8 dip north, while F1, F3 and F9 dip south. The total Gas in place (BScf) and the total Recoverable reserve (Tcf) calculated were 359.73 and 636.62 respectively. Production records interpretation showed decrease in reservoirs' productivity as a result of decline in the natural pressure of the reservoirs. From analysis results, it was deducted that the thin beds positively impact the reservoir petrophysics and the calculated recoverable reserve also impact reserve.

Inhaltsverzeichnis (Table of Contents)

• Chapter ONE
  • 1.0 Introduction
  • 1.1 General Statement
  • 1.2 Study Location
  • 1.3 Statement of the problem
  • 1.4 Objectives of study
  • 1.5 Physiographic Setting
    • 1.5.1 Topography
    • 1.5.2 Climate
  • 1.6 Scope and Methodology
  • 1.7 Previous work
• CHAPTER TWO
  • 2.0 Regional Geology of Texas
  • 2.1 Generalized Geology of Texas
    • 2.1.1 Geology of West Texas
  • 2.2 Geologic history of West Texas
  • 2.3 Regional Geology of Delaware Basin
    • 2.3.1 General Statement
    • 2.3.2 Geology of Delaware Basin
  • 2.4 Geologic Setting of West Waha and Worsham-Bayer Fields
    • 2.4.1 Ellenburger Group Reservoir Geology
      • 2.4.1.1 Ellenburger Group Depositional Facies Assemblages
      • 2.4.1.2 Karst Facies of Ellenburger Group
    • 2.4.2 Fusselman Formation Reservoir Geology
    • 2.4.3 Thirtyone Formation Reservoir Geology
    • 2.4.4 Undifferentiated Mississippian Reservoir Geology
• CHAPTER THREE
  • 3.0 Methodology
  • 3.1 Data Volumes
  • 3.2 Use of the Data
  • 3.3 Summary of the Data
  • 3.4 Place of Data Interpretation
  • 3.5 Procedure for Interpretation
    • 3.5.1 Well log correlation
    • 3.5.2 Calculation of Petrophysical parameters
    • 3.5.3 Reservoir attributes
  • 3.6 Seismic-to-well ties
  • 3.7 3D Seismic Interpretation
    • 3.7.1 Mapping of reservoirs
  • 3.8 Structural Framework/Fault Network Mapping
  • 3.9 Time-Depth Structure maps (Depth Conversion)
  • 3.10 Recoverable reserve estimation/Volumetric
  • 3.11 Production record interpretation
  • 3.12 Limitation of study
• CHAPTER FOUR
  • 4.0 Results and Discussion
  • 4.1 Well log correlation
    • 4.1.1 Petrophysical analysis
    • 4.1.2 Reservoir Attribute Analysis Result
  • 4.2 Seismic-to-well ties using check survey
  • 4.3 Structural Framework/Fault Network Mapping
  • 4.4 3-D Seismic Mapping
  • 4.5 Time-Depth Structure Maps
  • 4.6 Recoverable reserve estimation/volumetric result
  • 4.7 Production record interpretation

Zielsetzung und Themenschwerpunkte (Objectives and Key Themes)

This study aims to characterize the reservoir properties of the West Waha and Worsham-Bayer fields in the Southeastern Delaware Basin, West Texas, to determine the impact of thin beds on reservoir petrophysical analysis and to assess the impact of estimated recoverable reserve on the interpreted reservoirs.

• Impact of thin-beds on reservoir petrophysical analysis
• Influence of estimated recoverable reserve on reservoir characteristics
• Structural evolution of the basin and its role in trapping hydrocarbons
• Relationship between structures and stratigraphy in the area
• Causes of low natural gas recovery in the fields

Zusammenfassung der Kapitel (Chapter Summaries)

Chapter One provides an introduction to the study, outlining the general statement, study location, statement of the problem, objectives, physiographic setting, scope and methodology, and previous work conducted in the area.

Chapter Two delves into the regional geology of Texas, starting with a generalized overview of the state's geology and specifically focusing on the geology of West Texas. It then provides a detailed exploration of the Delaware Basin, its geological history, and the geologic setting of the West Waha and Worsham-Bayer fields.

Chapter Three outlines the methodology used in the study. This includes the data volumes used, how the data was used, a summary of the data, the place of data interpretation, and a detailed description of the interpretation procedures for well log correlation, petrophysical parameters calculation, reservoir attributes, seismic-to-well ties, 3D seismic interpretation, structural framework mapping, time-depth structure maps, recoverable reserve estimation, and production record interpretation. It concludes with a statement on the limitations of the study.

Schlüsselwörter (Keywords)

This work focuses on reservoir characterization, thin-beds, recoverable reserves, natural gas recovery, structural evolution, stratigraphy, and the Delaware Basin. It also involves the application of integrated data sources such as well logs, 3D seismic data, and production data.

• Hochschule: University of Ibadan
• Note: 700
• Autor: Emelda Orakwue (Autor:in)
• Erscheinungsjahr: 2010
• Seiten: 185
• Katalognummer: V215030
• ISBN (eBook): 9783656428244
• ISBN (Buch): 9783656433811
• Sprache: Englisch
• Schlagworte: reservior, west, waha, worsham-bayer, fields, southeastern, delaware, basin, texas, using