API 39 : 1998

1 INTRODUCTION
1.1 Fracturing fluid rheology (viscosity) and the hydraulic
     fracturing process
1.2 Cross-linked fracturing fluid rheological behavior
1.3 Objectives and limitations of this document
2 REFERENCES
2.1 Standards
2.2 Other referenced publications
3 DEFINITIONS AND NOMENCLATURE
3.1 Definitions
3.2 Nomenclature
4 LABORATORY PROCEDURES
4.1 Fluid preparation and testing
4.2 Equipment requirements
4.3 Instrument calibration
5 FIELD PROCEDURES
5.1 Equipment requirements
5.2 Preparation of linear polymer solutions
5.3 Special field testing equipment
5.4 Field testing procedure
5.5 Discussion of commonly observed problems
6 CALCULATION PROCEDURES FOR VISCOUS PROPERTIES
6.1 General concepts
6.2 Couette geometry
6.3 Example calculation: couette geometry with standard
     R1-B5 geometry
APPENDIX A BASIC RHEOLOGICAL CONCEPTS
APPENDIX B TYPES OF FLUIDS
Figures
1 Typical full range shear stress vs. shear rate rheograms
     for cross-linked water-based fractured fluids
2 Segmented portion, shear stress vs. shear rate rheograms
     for cross-linked water-based fracturing fluids
3 Shear stress graph for a power-law fluid
A-1 Graph of shear stress data
A-2 Graphs of omega vs. shear stress for the B2-extended bob
     and the B5-extended bob
A-3 Shear stress graph for a power-law fluid
A-4 Viscosity measurements for the delayed titanium HPG gel
     using nominal shear rate of 100 sec-1 at 200 deg F
A-5 Shear rate distribution in couette region
A-6 Comparison of viscosity measurements for the delayed titanium
     HPG gel with 0.1 lb/1000 gal AP using VASR method at 150 deg F
A-7 Comparison of viscosity measurements for the delayed titanium
     HPG with 0.1 lb/1000 gal AP using VASR method at 200 deg F
B-1 Graphical explanation of the shear stress-shear rate
     relationship
B-2 Illustration of shear stress relationship for classical fluids
B-3 Apparent viscosity of an HPG fluid over a wide range of shear
     stress
B-4 Viscosity vs. time
Tables
1 Description of equipment for laboratory testing
2 Rotor-bob combinations
3 Calibration factors for dead weight testing
4 Results, calculation of power-law parameters
5 Results, calculation of actual power-law viscosity at a shear
     sweep time of 30 mins
B-1 Typical fracturing fluids additives

Specifies standard testing procedures, such as laboratory processing, field processing and calculation processing for viscous properties, for the measurement of certain theologiocal properties of common cross-linked water-based fracturing fluids used in hydraulic fracturing treatments.