Frac Talk Laura Schafer 4 March 2016
My Path to Frac Education MS, BSc Chemical Engineering Colorado School of Mines Career Schlumberger 2002 2010 Well Services Manager Fracturing Cementing Coil Tubing Sand Control Chevron 2010 2012 Global Shale Completions
The First Frac... 1947, Stanolind Oil in the Hugoton Gas Field, SW Kansas Frac Fluids and Proppant 1,000 gallons of naphthenic acid + palm-oil thickened gasoline 20,000 lbm sand from the Arkansas River
Agenda Frac Design and Dimensions Why do oil companies frac? How big is a frac? Why is frac different in shale? Or why I did not hear about frac before 2008? Where is a frac in relation to the water table? Can I frac to surface? Frac Execution Well completion operations Surface equipment Frac fluid design Frac job plots Post-frac operations Concerns for the Concerned Citizen
Why do companies frac? A molecule of gas travels 1-2 inches per year in 100 500 nd -- George King, SPE q Darcy s Law 2 kh p p r B ln r e w e 1 2 w s CfD = k p * w k f * l
How big is a frac?
Why shale is different Importance of Surface Area Vertical 50 ft zone 5.5 in wellbore 1x area Fracced = 60x Horizontal 5000 ft lateral 5.5 in wellbore 100x area Fracced = 10000x
Why shale is different Horizontal Well Orientation
Where is the Water Table Well Construction Example Casing Design Example Casing Design 16 Conductor To 80 ft Aquifer Water Well Aquifer 24 Conductor To 100 ft 16 Csg To 500 ft Water Well 10-3/4 Csg 45.5# J55 To 2000 ft 11-3/4 Csg 42# H40 To 1000 ft Coal 8-5/8 Csg 32# J55 To 2000 ft Nonpotable Water 7-5/8 Csg 29.7# P110 To 13178 ft 5-1/2 Csg 23# P110 Tieback at 12930 5-1/2 Csg 21.4# P110 12930 to TD 5-1/2 Csg 20# P110 To TD Shale or Reservoir Rock Shale or Reservoir Rock Drawings not to scale
Where is the Water Table Confirmation of Frac Height and Width
Where is the Water Table Frac Height Versus Depth, Barnett
Where is the Water Table Frac Height Versus Depth, Marcellus
Agenda Frac Design and Dimensions How big is a frac? Why is frac different in shale? Where is a frac in relation to the water table? Can I frac to surface? Frac Execution Well completion operations Surface equipment Frac fluid design Frac job plots Post-frac operations Concerns for the Concerned Citizen
Well Completion Structure To heel of well Toe of well
Well Completion Structure To heel of well Toe of well
Well Completion Structure
Shale Completion: Example
Frac Fluid Design Objective: Develop enough viscosity at low flow rates to suspend proppant without adversely effecting hydraulic horsepower required at surface Typical Slickwater Formulation 99.86% water 0.09% friction reducer 0.03% biocide 0.02% scale inhibitor Typical Crosslinked Polymer Formulation 25lbm/1000 gal borate crosslinked guar Perforation Cleaning Fluid 15% HCl Corrosion Inhibitor
Frac Focus Source for Frac Chemical Information
Shale Completion: Example Fracture Treatment Specs: Parameter Value Injection Rate 100 bpm Fluid Volume 350,000 gals Proppant Mass 350,000 lbm Proppant Type 40/70 ceramic proppant 7 ½% HCL Acid 2,000 gals Fluid Type Slickwater Clusters 3 ea Cluster Spacing 75 ft Perforation Phasing 60 Degrees
Fracture Treatment Rate held constant Frac Breakdown Surface Pressure includes friction and density effects Pressure rise due to cutting proppant Shut-in at end of flush Step rate up in small steps Maintain annulus pressure watch for leaks ISIP Friction Effect Leak-off Prop loading usually 0.25 lb/gal to 3 lb/gal Wellhead Shut-in Source: SPE 140105, 2011
Well Completion Structure Post Frac Operations Clean Out Rig up coil tubing to mill out plugs Clean debris from wellbore and kick-off well if necessary Flowback Open up well to return frac fluid to surface; flow until water rate down Switch to production
Agenda Frac Design and Dimensions How big is a frac? Why is frac different in shale? Where is a frac in relation to the water table? Can I frac to surface? Frac Execution Well completion operations Surface equipment Frac fluid design Frac job plots Post-frac operations Concerns for the Concerned Citizen
Top Concerns for Concerned Citizens Emergency Response Plans / Preparedness Emissions Tanks Compressors Frac Trucks Spills Abandoned wells Setbacks Water resource utilization
` Questions?
Questions?