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CLEANER. FASTER. SMARTER.
PRESENTATION CONTENT
Current methods Oil & Gas Operators use to manage and minimize waste
(whole fluids and associated cuttings) during a typical land-based drilling
operation.
Drilling fluids selection and region generally determines how these
practices are performed.
CLEANER. FASTER. SMARTER.
TYPES OF OPERATIONAL WASTES
Drilling Fluids
Diesel-Based drilling fluids
Non-aqueous drilling fluids (synthetic oils)
Water-based drilling fluids
Air/Mist operations
Cuttings All wells drilled produce wellbore cuttings
Amount varies depending on depth, hole size and washout
De minimis Wastes Rig floor
Cellar fluids
Fluids adhering to drill pipe during trips
Containment vessels or tank bottoms
Rainwater and rinse water
CLEANER. FASTER. SMARTER.
CURRENT PRACTICES TO MANAGE DRILLED CUTTINGS
Open pits Mainly used for water-based operations, i.e. surface muds, low chloride fluids, low or no oil content in water-based fluids
Regulations determine if this is possible
Collect cuttings with adhered fluids in cuttings boxes (referred to as closed–loop systems) Most common practice used
Insures that all cuttings and adhered drilling fluids are captured for disposal
Requires transfer into movable storage containers which are then sent offsite for disposal
Requires adequate trucking coordination during the course of the well
Requires a large foot-print on location
Adds to overall well costs as opposed to disposal in open pits
CLEANER. FASTER. SMARTER.
CURRENT PRACTICES TO MANAGE DRILLING FLUIDS
Surface Storage Vessels and Frac Tanks Storage tanks vary in size holding as little as 25 barrels or as much as 1000 barrels (42,000 gallons)
Frac tanks hold approximately 500 bbl. of volume
Typically 4-8 Frac tanks are on location at all times to contain drilling fluids and make-up water, drill water
Hoses and valves are used to transfer fluids and help prevent leaks during storage and transfers
Drip pans and buckets are used to catch fluids when disconnecting hoses or valves
Air may be blown thru lines to rid lines of fluids before moving or disconnecting hoses
Pin connectors are used to prevent hoses from working themselves loose during pumping operations
Impermeable liners under storage vessels and frac tanks are used in a lot of operations in-case of spills so that no fluids contact the soil
Sight glasses on vessels help determine levels of fluids
Strapping tanks is done before and after fluid movement
Some vessels use “Floats” or shut-off devices which help control fluid levels
CLEANER. FASTER. SMARTER.
CURRENT PRACTICES TO MANAGE DRILLING FLUIDS
Rig pit system
Optimize pit system usage to fit the volume needed for that particular well; by-pass some pits with the
return flow if volume is not needed
System volume capacity varies among rig companies but standard surface system will hold appr. 1,000 to
1,500 barrels
Most likely source of a spill will occur in surface system during transfer of fluids from storage to surface
system
Each operator and rig combination have specific rules to help avoid any spill occurrences. i.e. some
operators require only transfer of fluids be performed during daylight hours; only qualified personnel can move fluids
and work valves; at least two persons must be present during transfers, etc.
Shale shakers screen selection is critical to minimize drilling fluids adhering to cuttings
CLEANER. FASTER. SMARTER.
CURRENT PRACTICES TO MANAGE DRILLING FLUIDS (CONT.)
Rig pit system
Large volumes of water required to clean surface pits; water can be reused by slightly treating with flocculants
to remove unwanted solids
System volume capacity varies among rig companies but standard surface system will hold appr. 1,000 to 1,500
barrels; reducing workable volume requires less dilution and leads to less overall volume of fluid on location
Working with a lower system volume helps prevent chance of overflowing of pits during transfers or flow
influxes from wellbore ; this may not be possible depending on down hole losses or needing fluid for well
control purposes
Recirculate shaker slide water to rinse cuttings into open top tanks or reserve pits
Use of rig vacuums instead of pressure washing where possible
Limit use of rinse water but in the same notion, recycle it
CLEANER. FASTER. SMARTER.
TYPICAL WASTE MINIMIZATION BY AREA
Texas – West Texas, Panhandle, South
Oklahoma
North Dakota
Northeast – Pa. Ohio, W. Virginia
CLEANER. FASTER. SMARTER.
Diesel-based fluids; Brine based fluids
Closed-loop systems for OBM’s
Lined pits for WBM’s
Methods to limit wastes in this area:
- Include using available production brine as dilution water in the drilling fluids.
- Drill with just brine water if formation pressures allow
WEST TEXAS
CLEANER. FASTER. SMARTER.
TEXAS Panhandle
Diesel-based and freshwater-based fluids
Closed-loop systems for OBM’s
Lined pits for WBM’s
Methods to limit wastes:
Dryers for OBM operations
Dewatering to reuse water
CLEANER. FASTER. SMARTER.
TEXAS South Texas
Largely OBM with some freshwater and brine- based fluids
Closed-loop systems for OBM’s
Lined pits for WBM’s
Some landowners may allow all types of fluids
into land pits
CLEANER. FASTER. SMARTER.
OKLAHOMA Diesel-based and freshwater-based fluids
Closed-loop systems for OBM’s
Lined pits for WBM’s
Methods to reduce wastes:
Reuse water by dewatering
Dryers for OBM Source: Hart’s E&P
CLEANER. FASTER. SMARTER.
NORTH DAKOTA
Diesel-based and brine- based fluids
Closed-loop containment for both
fluid systems
CLEANER. FASTER. SMARTER.
NORTH EASTERN U.S. Synthetic, brine and freshwater-based systems.
Diesel-based fluids can also be used in the region.
Closed-loop systems for ALL systems
Methods used to limit wastes:
Extra measures on locations are taken for containment of fluids and cuttings
Use of EIR (Environmental Impact Reduction) which is the use of chemicals with the least impact to the environs
CLEANER. FASTER. SMARTER.
References http://web.ead.anl.gov/dwm/regs/state/ndakota/index.cfm
Drilling Fluids Processing Handbook; ASME. 2005