Hydrocarbon accumulations in petroleum reservoirs

196 Pages·2013·4.1 MB·English

by  Dieudonne Delaihdem

DECLINE CURVE ANALYSIS AND ENHANCED SHALE OIL RECOVERY BASED ON
EAGLE FORD SHALE DATA
By
Dieudonne K. Delaihdem
RECOMMENDED:
_..,Dr. Abhijit Dandekar
~-
Dr. Abhijit Dandekar
Chair, Department of Petroleum Engineering
APPROVED:

DECLINE CURVE ANALYSIS AND ENHANCED SHALE OIL RECOVERY BASED ON
EAGLE FORD SHALE DATA

A
THESIS

Presented to the Faculty
of the University of Alaska Fairbanks
in Partial Fulfillment of the Requirements
for the Degree of
MASTER OF SCIENCE
By
Dieudonne K. Delaihdem, B.S.
Fairbanks, Alaska
December 2013
ABSTRACT
Transient and fracture dominated flow regimes in tight permeability shale reservoirs with hydraulically
fractured horizontal wells impose many unconventional challenges. These include execution of
appropriate shale decline curve analysis and the optimization of hydrocarbons recovery. Additionally,
short production profiles available are inadequate for accurate production decline analysis.

This research assessed the effectiveness of Arps’ decline curve analysis and recently established methods-
-power law exponential analysis, logistic growth analysis, Duong’s method and the author’s approach--to
predict future production of horizontal wells in the Eagle Ford Shale. Simulation models investigated
history matching, enhanced shale oil recovery, and drainage area beyond stimulated reservoir volume.

Traditional Arps’ hyperbolic method sufficiently analyzed past production rates, but inaccurately
forecasted cumulative productions. The recent decline models show slight variations in their past
performance evaluations and forecasting future production trends. The technique proposed and used in
this work enhanced the successful application of Arps’ hyperbolic decline from 32.5% to 80%.

Simulation results indicate 4.0% primary oil recovery factor and 5.8% enhanced shale oil recovery factor
using CO miscible injection. Based on pressure observed outside of the stimulated reservoir volume,
2
limited to the range of data used in this study, drainage area outside stimulated reservoir volume is not
significant.

vii
DEDICATION
To God is the Glory
Praises to the Lord; His Love Endures Forever

ix
TABLE OF CONTENTS
Signature Page……………………………………………………………………………………..i
Title Page …………………………………………………………………………………………iii
ABSTRACT ..................................................................................................................................... v
DEDICATION ............................................................................................................................... vii
TABLE OF CONTENTS ................................................................................................................ ix
LIST OF FIGURES ...................................................................................................................... xiii
LIST OF TABLES ....................................................................................................................... xxii
ACKNOWLEDGEMENT .......................................................................................................... xxiv
Chapter 1 Introduction ..................................................................................................................... 1
1.1 Shale Oil Reservoirs ............................................................................................................ 1
1.2 Shale Oil- What is it? ........................................................................................................... 2
1.3 Shale Play Development ...................................................................................................... 3
1.4 Purpose and Scope of Study ................................................................................................ 4
Chapter 2 Literature Review ............................................................................................................ 6
2.0 Introduction .......................................................................................................................... 6
2.1 Geology ................................................................................................................................ 7
2.2 Decline Curve Analysis ..................................................................................................... 11
2.2.1 Arps Decline Curve Analysis ..................................................................................... 12
2.2.2 Power Law Exponential Analysis .............................................................................. 15
2.2.3 Logistic Growth Analysis .......................................................................................... 16
2.2.4 Duong’s Method ........................................................................................................ 17
2.3 Analyses of the Eagle Ford Shale ...................................................................................... 19
2.3.1 Reservoir Fluids ......................................................................................................... 19
x
2.3.2 Natural Fractures ........................................................................................................ 20
2.3.3 Reservoir Stimulation and Wellbore Completions .................................................... 22
2.3.4 Simulation .................................................................................................................. 25
2.4 Improving Shale Oil Recovery by CO Injection and CO as Frac Fluid .......................... 29
2 2
Chapter 3 Eagle Ford Production History Assessment Using Various Decline Curve Analysis
Techniques ..................................................................................................................................... 36
3.0 Introduction ........................................................................................................................ 36
3.1 Methods.............................................................................................................................. 37
3.1.1 Data Preparation before the Analysis ......................................................................... 37
3.1.2 Arps’ Decline Models Applications ........................................................................... 37
3.1.3 Power Law Exponential (PLE) Analysis Application................................................ 38
3.1.4 Logistic Growth Analysis (LGA) Application ........................................................... 39
3.1.5 Duong’s Decline Curve Analysis Method ................................................................. 40
3.1.6 Logistic Arps’ Hyperbolic Approach (LAHA) .......................................................... 41
3.2 General Results .................................................................................................................. 42
3.2.1 Data Preparation before the Analysis ......................................................................... 42
3.2.2 Arps’ Decline Curve Analysis ................................................................................... 45
3.2.3 Power Law Exponential Analysis (PLE) ................................................................... 48
3.2.4 Logistic Growth Analysis (LGA) .............................................................................. 51
3.2.5 Duong’s Decline Curve Analysis Method ................................................................. 52
3.2.6 Logistic Arps Hyperbolic Approach (LAHA) ........................................................... 57
3.3 Discussion of General Results ........................................................................................... 60
Chapter 4 Eagle Ford Shale Oil Production Decline Analysis Specific Results ............................ 63
4.0 Introduction ........................................................................................................................ 63
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4.1 Burleson County ................................................................................................................ 63
4.1.1 Introduction ................................................................................................................ 63
4.1.2 Specific Results of Shale Oil Production Decline Analysis in Burleson County ...... 65
4.2 Leon County....................................................................................................................... 70
4.2.1 Introduction ................................................................................................................ 70
4.2.2 Specific Results of Shale Oil Production Decline Analysis in Leon County ............. 71
4.3 Brazos County .................................................................................................................... 76
4.3.1 Introduction ................................................................................................................ 76
4.3.2 Specific Results of Shale Oil Production Decline Analysis in Brazos County .......... 77
4.4 Lee County ......................................................................................................................... 81
4.4.1 Introduction ................................................................................................................ 81
4.4.2 Specific Results of Shale Oil Production Decline Analysis in Lee County ............... 82
4.5 Gonzales County ................................................................................................................ 84
4.5.1 Introduction ................................................................................................................ 84
4.5.2 Specific Results of Shale Oil Production Decline Analysis in Gonzales County ...... 86
4.6 Karnes County ................................................................................................................... 91
4.6.1 Introduction ................................................................................................................ 91
4.6.2 Specific Results of Shale Oil Production Decline Analysis in Karnes County.......... 92
4.7 Dimmit County .................................................................................................................. 98
4.7.1 Introduction ................................................................................................................ 98
4.7.2 Specific Results of Shale Oil Production Decline Analysis in Dimmit County ........ 98
4.8 Zavala County .................................................................................................................. 102
4.8.1 Introduction .............................................................................................................. 102
4.8.2 Specific Results of Shale Oil Production Decline Analysis in Zavala County ........ 103