1. Oil-Field Hydraulics Chapter 2 Production Equipment
PTRT 1321
Oil-Field Hydraulics
Chapter 2
Production Equipment

2. Introduction Many devices and tools used in a producing well
Installed on the surface
Control panels
Injection pumps
Control lines
Flow couplings
Safety valves
Installed below the surface
Mandrels
Packers
Landing nipples
Subs
Guides

3. Typical sub-surface equipment
Some equipment is permanently
installed
Some installed only during workover
Some equipment is run in as part of
the original string
Some run in on tubing or wireline

4. Christmas Tree (Well Head)
Mechanical structure
Spools
Flanges
Connections
Hangers
Control of fluid flow and pressure
Valves
Chokes
Pressure gauges
Carelessness can prove fatal

6. Component Descriptions
Pressure gauges – display tubing, casing or annular pressures
Gauge flange (cap) – seals the top of the tree (often a hammer fitting). Remove to allow access to the well for wireline, coil tubing or other workover units.
Crown (swab) valve – isolate the well to allow access through cap
Flow (cross) tee – allows tools to be run into the well while still producing
Wing valve – shuts in the well for most routine operations not requiring access to the well bore

7. Choke – controls the amount of flow from the well
Master valves – primary shut off valves, open most of the life of the well, lowest master valve used as last resort to avoid wear and tear
Tubing hanger – supports the tubing string and seals off the casing annulus
Casing valve – provides access to the annular space between the tubing and the casing
Casing hanger – slip and seal assembly from which the casing is suspended
Casing – string of pipe the keeps the wellbore from caving in and prevents vertical communication from one zone to another.
Tubing – string of pipe through which produced fluids flow

8. Back-pressure valves Installed into the tubing hanger
Two types available
One-way check valve
Flow only into the well
Two way check valve
Holds pressure in either direction
Allow Christmas tree to be removed or replaced without having to kill the well

9. Type H Back Pressure Valve
Type H Two-way Check Valve

10. Christmas Tree Removal
Careful planning is a must
Consider the following questions:
Is the tree to be removed before or after the rig is moved in?
Will service on the tree (if required) be at a shop or in the field?
Is the manufacturer rep present and are spare parts available on site?
Is the BOP equipment ready to be installed?
Is the well to be killed or worked on under pressure (live)

11. Christmas Tree Removal (cont)
Other considerations:
All exposed flanges should be protected and all BOP flanges should be inspected and cleaned prior to use
New seal rings should be available as metal seal rings cannot be reused
Tubing and casing pressures should be checked with gauges KNOWN to be working.
If the well is being killed the casing should be installed and cemented properly
No communication between the casing and tubing should exist. All points of failure should be repaired

12. Removing the well head
Kill the well by bullheading kill fluid into the formation
Pumping fluid down the tubing and displacing the formation fluid back into the formation
Calculate the tubing volume and note when that much kill fluid has been pumped
A few interesting notes:
Clear fluids can fall faster than they can be pumped (pressure will drop)
Gas migrates faster than it is bullheaded
Too much fluid pumped down hole can cause formation damage
Increase in pump pressure should signal that the kill fluid has reached the bottom

13. Finishing steps Record the volume pumped and the pressures
Shut in the well and check for pressure build up for about 1 hr
Have a full opening valve available with proper threads and sized to fit the tree
If no pressure build up occurs remove the tree and install a BOP stack

14. Casing
Steel pipe that runs from surface to specified depth in well (4 1/2 to 20 inches)
Hangs from casing hanger and cemented into the hole
Several casings can be used to reduce cost
Casing prevents lost circulation and comingling of well fluids
Foundation for surface equipment

15. Liners Casing hung inside an existing casing
Hangs from liner hanger installed near the bottom of the casing in which the liner is run
Many reasons to use a liner
Cost
Isolate problems from other zones such as lost circulation
Handling issues same as casing
Inspect and careful handling
Thread protectors removed only prior to stabbing the joint
Sometimes a stabbing guide is used to prevent cross-threading

16. Liner hanger
Supports the liner near the bottom of the last string of casing
Both grip the inside of the casing
Mechanical slips (j-slot and rotation)
Hydraulic slips (hydraulic pressure pushes the slips outward)

18. Tubing Majority of wells are produced through tubing
Protects casing from pressure and corrosion
Tubing is suspended from the well head
Sizes from fractions of an inch to several inches (2 7/8 and 2 3/8 common sizes)
Strength classifications such as J-55 or N-80
Also available with protective coatings applied for corrosion protection

19. Work Strings
Length of tubing or drill pipe used for workover or completion
Can be the production tubing or replace the production tubing with drill pipe
In either case tubing is removed, tools installed on the end and the tubing is run back in the hole
Of course the OD must be small enough to fit into the well without restriction

20. Packers Seals the annular space between the tubing and the casing
Protects the casing from pressure and reservoir fluids
Multiple packers isolate multiple completions to prevent commingling
Special packers are also available for squeeze cementing, acidizing and fracturing
Often a gauge run is made (scraper and junk basket) to confirm full size through the length

21. Packer
slips
Elastomer seal

22. Setting the Packer
Hydraulic – pump out ball seat near the bottom of the tubing provides the means to apply the setting pressure
Mechanical – packer plus a seal assembly run in on tubing to the setting depth. Upper slips are released with right-hand rotation of tubing and then lower slips are set with upward tension on the tubing
Electric wireline – electrical current sets off a small explosive charge in a setting assembly that gradually builds up gas pressure to set the packer.
Sandline or slickline – similar to wireline except concussion from a go-devil dropped into the well sets off the charge

23. Seal Nipples
Sometime installed in packers to prevent fluid and pressure from escaping between the tubing and the packer
Run in on bottom of tubing and inserted into packer
Latch type (locator) locks into packer so tension may be applied
Sealing elements can be redressed at the job site if needed

24. Anchor Seal
Nipple Assembly
Locator Seal
Nipple Assembly

25. Bridge Plug Set into casing to prevent fluid movement in the casing
Permanent or retrievable
Seals the well to provide added safety when removing the well head
Can also be set between perforations to isolate lower zone while workover is performed on upper zone

26. Blast Joints Used in multiple completions
Protect section of tubing opposite upper perforations against erosion and/or corrosion from produced fluids
Abrasion-resistant steel or normal steel coated with plastic, rubber, tungsten carbide or ceramic

27. Safety Joints Special large-profile threads
Quick release of tubing string from down hole equipment
Parted by reverse rotation or shearing
Used above tools that might become stuck in the hole
Allows for upper sections of tubing to be retrieve and fishing or other workover tools to be used to recover stuck sections

28. Sliding sleeve Allows circulation between casing and tubing
Installed in tubing
Allows upper zone to be produced or shut off at later time
Can be used for treating or acidizing a zone
Ports can be opened and closed:
Wireline
Jarring

29. Mandrels
Installed in tubing that allows communication between tubing and casing at the location of the mandrel
Gas lift mandrel on which a gas lift valve is mounted
Sidepocket mandrel allows gas lift valves to be installed and removed with wireline without pulling the tubing
Other mandrels will accept plugs, subsurface control valves or downhole chokes

30. Landing Nipples
Small sub into which flow-control devices can be installed
ID slightly smaller that tubing ID
Seating area for pump-down and wireline flow-control devices
ID’s vary according to the tools they receive
Larger ID’s used near the surface than at bottom to allow tools with different ID’s to be set in the same string
Usually have a locking device to hold the tool in place

31. Seating nipples
Provide a place in which flow-control devices can be installed and retrieved by wireline
Can be used to set:
Blanking plugs for shutting in the well or testing the tubing string
Circulating blanking plugs
Equalizing check valves
Velocity-type safety valves
Chokes to reduce surface flowing pressures
Instrument hangers for pressure ro temperature recorders

32. Flow couplings
Smaller landing nipple ID causes turbulent flow above and below
Sand and other solids can erode the tubing as a result
Flow couplings (collars) are installed in the tubing string above and below the landing nipple
Usually choose the same ID as the tubing

33. Retrievable cementer Special mechanically-set packer Used to do:
Squeeze cementing
High-pressure acidizing job
Well test
Does not become part of the completed well

34. Cement retainers Special packers used in squeeze cementing
Set with wireline or tubing
Must be drilled or milled out
Retainer valve closes when tubing is picked up and opens when tubing is set down
Closed valve holds the final squeeze pressure as excess cement is circulated out
Also keeps hydrostatic pressure from contacting the squeezed zone in low fluid level wells during batch squeeze

35. Circulating washers Used to acidize or wash perforations
Straddle-type tool with swab cups or inflatable packers that can be replaced easily at the well site
Sleeve on upper portion opens and closes circulating ports between the tubing and casing
Swab cup spacing is adjustable to the desired zone can be isolated (6” to 42” in 6” increments)
Ports are opened as tool is retrieved to allow fluid to drain from the tubing

36. Packer Milling Tools
Usually faster and cleaner to mill a packer’s slips and retrieve the packer than drill through
Only a small amount of the slips need to be cut to release a permanent packer
Mill is labeled A
Mill engaging the packer is labeled B
Pick up device may be run in with the mill, latches onto the packer after it is cut loose A B

37. Junk and Boot Baskets Remove milled or drilled debris from a well
Circulation sweeps cuttings into an inner chamber (basket)
Heavy materials that cannot be circulated are thus caught and retrieved when the basket is retrieved.
Caution to not apply excess torque or weight or fingers of junk basket may break
Boot basket is similar but with narrow annulus to cause high velocity flow. As fluid leaves narrow annulus velocity drops suddenly causing the debris to drop vertically into the basket

38. Casing Scrapers Used to remove foreign substances from casing ID Scale
Perforating burrs
Cement
Rotated or reciprocated
Rubber blocks under the scraper blades to allow flex
Caution to not excessive wear the casing

39. Casing Rollers Several rugged, heavy-duty rollers mounted on a mandrel
Rollers mounted on different centerlines
As tool rotates only one roller at a time contacts the casing
Eccentric motion can restore collapsed, dented, or buckled to its normal diameter and roundness
Operates with ample fluid circulation and slow rotation speeds

40. Centralizers Used to center in the well bore: tubing Casing
Perforating guns
Wireline tools
For example can keep the casing centered in the hole while cementing. This allows turbulent flow needed to avoid void areas