Applied Matrix Acidizing of Carbonate Reservoir

Preface
Contents
Abbreviations
List of Figures
List of Tables
1 Basic Objectives and Concepts of Matrix Acidizing
	1.1 Introduction
	1.2 Formation Damage
	1.3 Types of Damage Formation Damage
		1.3.1 Natural Damage
		1.3.2 Induced Damage
	1.4 Formation Damage Assessment Comprehensive Considerations
		1.4.1 Reservoir Geology and Mineralogy
		1.4.2 Reservoir Fluids
		1.4.3 Production of Nearby Wells
		1.4.4 Well Production History
		1.4.5 Drilling History
		1.4.6 Cementing Program
		1.4.7 Well Completion and Perforation Reports
		1.4.8 History of the Well Workover
		1.4.9 Well Acidizing and Stimulation History
	1.5 Types of Formation Stimulation Methods
		1.5.1 Acidizing
		1.5.2 Fracturing
		1.5.3 Thermal Stimulation
	1.6 Objectives of Matrix Acidizing
		1.6.1 Improving Well Productivity
		1.6.2 Enhancing Reservoir Performance
		1.6.3 Restoring Formation Permeability
		1.6.4 Economic Considerations
	1.7 Carbonate Reservoirs
		1.7.1 The Composition and Characteristics of Carbonate Reservoirs
	1.8 Acid-Rock Interactions
	1.9 Types of Acids in Acidizing
		1.9.1 Mineral Acids
		1.9.2 Organic Acid
		1.9.3 Mixed Acid
	1.10 Reservoir Permeability and Porosity
	1.11 Factors Affecting Acidizing Success in Carbonate Reservoirs
	1.12 Parameters Affecting Acidizing Operation
	1.13 Matrix Acidizing of Carbonate Formations
	1.14 Field Applications
	1.15 Questions
	References
2 Estimating the Formation Fracture Pressure Through Geomechanical Modeling
	2.1 Introduction
	2.2 Elasticity Parameters
		2.2.1 Stress
		2.2.2 Strain
		2.2.3 Stress and Strain Relationship
	2.3 Uniaxial Compressive Strength
	2.4 Pore Pressure
	2.5 Estimation of the Magnitude of the Main Stresses in Place
		2.5.1 Vertical Tension (σV)
		2.5.2 The Minimum Horizontal Stress (h)
		2.5.3 Maximum Horizontal Stress (H)
	2.6 Determining the Direction of the Main Stresses in Place
	2.7 Image Logs (FMI)
	2.8 Elastic Moduli
	2.9 Construction of Geomechanical Model
		2.9.1 Determination of Elastic Constants
		2.9.2 Static Elastic Moduli
		2.9.3 Estimation of Rock Resistance Parameters
		2.9.4 Overburden Stress
		2.9.5 Horizontal In-Situ Stresses
		2.9.6 Biot Coefficient
		2.9.7 In-Situ Stress Regime
		2.9.8 Estimation of Temperature Conditions
	2.10 Questions
	References
3 Static and Dynamic Tests
	3.1 Introduction
	3.2 Experiment Design
	3.3 Investigating Influencial Parameters
		3.3.1 Choosing the Type of Acid
		3.3.2 Concentration
		3.3.3 Rock to Acid Ratio
		3.3.4 Time
	3.4 Rotary Disk Reactor
		3.4.1 Rotating Disk Theory
		3.4.2 How to Work
		3.4.3 Effect of Rock Porosity
		3.4.4 Rock Mineralogical Effect
		3.4.5 Effect of Additives on Reaction Rate
	3.5 Hydrochloric Acid
		3.5.1 Stoichiometry, Kinetics, and Equilibrium Constant
		3.5.2 Determination of Time and Ratio of Rock to Acid
		3.5.3 Determining the Optimum Concentration
	3.6 Hydrochloric Acid and Methanol
		3.6.1 Dissolution Test
	3.7 13% Acetic Acid Dissolution Test
		3.7.1 Acetic Acid pH at 13%
	3.8 Determination of the Optimum Time and Volume Ratio of Hydrochloric Acid to Acetic Acid
		3.8.1 Dissolution Test
		3.8.2 pH
	3.9 Viscosity Increasing Fluids
	3.10 Comparison of Selected Solutions
	3.11 Perform Surface Tension and Contact Angle Tests
		3.11.1 Introduction
		3.11.2 Acidizing Additives
	3.12 Guidelines for Laboratory Evaluation of Acidizing Additives
		3.12.1 Compatibility Testing
		3.12.2 Test Method
		3.12.3 Iron Reducing Agent
		3.12.4 Additive Evaluation for Removing Hydrogen Sulfide Gas
		3.12.5 Evaluation of Suspending Agent
		3.12.6 Anti Sludge Evaluation
		3.12.7 Evaluation of Non-emulsifiers
		3.12.8 Acid Corrosion Inhibitor and Intensifier Evaluation
		3.12.9 Review of Surface Tension Reducer
		3.12.10 Experiment to Determine the Optimal Concentration of Mutual Solvent Additive in the Pre-injection Fluid
		3.12.11 Emulsifier Agent Acid Additive Evaluation
		3.12.12 Evaluation of Clay Stabilizer
		3.12.13 Viscoelastic Evaluation of Surfactant
		3.12.14 Foaming Agent Evaluation
		3.12.15 Hydrochloric Acid Evaluation
		3.12.16 Acetic Acid Evaluation
		3.12.17 Evaluation of Ammonium Bifluoride (ABF)
		3.12.18 Benzoic Acid Evaluation
		3.12.19 Asphaltene Solvent Evaluation
	3.13 Coreflood Tests
		3.13.1 Introduction
	3.14 Coreflood with Acid
		3.14.1 Matrix Acidizing Test Details
		3.14.2 Matrix Acidizing Method
		3.14.3 Acid Preparation
		3.14.4 Determining the Optimal Flow Rate
		3.14.5 Coreflood Test Steps
	3.15 Questions
	References
4 Analyzing and Contrasting Laboratory Results with Commercial Software
	4.1 Introduction
	4.2 Required Information
	4.3 Test Design Method in Software
		4.3.1 Rationale Behind the Selection of Experiment Design Levels
	4.4 Selecting the Rate and Volume of Acid Injection
	4.5 Discussion
		4.5.1 Optimal Acid Selection
		4.5.2 Information and Outcomes from the Software
	4.6 Questions
5 Economic Evaluation and Estimation
	5.1 Introduction
	5.2 Economic Calculations
		5.2.1 Essential Costs for Acidizing
		5.2.2 Flow Rate Changes After Acidizing
		5.2.3 Estimation of Costs and Profits Resulting from Acidizing
	5.3 Fold of Increase (FOI)
		5.3.1 Maximize NPV Through Informed Decisions
	References