Exam 2 completions lecture Flashcards
What is the difference between “hard rock” completion and “soft rock” completion?
A “hard rock” completion does not make any sand, while “soft rock” completion does make sand.
what are two distinct charachteristics about packers?
The distinct charactheristics about packers are that they are retrievable and permanent.
When does the completion phase of a well begin?
When the bit enters the formation!!!!
what happens if skin remains in completion phase of a well?
If the skin remains, a workover is the only way to remove it.
what is one important point about completion type
Must allow flexibility of future operations
Need to think of what possible future operations there maybe.
what is important point # 2 on completion type?
Must absolutely get a good primary cement job
Planning to do remedial (cure) cementing is poor planning
what happens when Completion Begins?
Typical hard rock completion includes running and cementing production casing in place.
What does getting a good cement job mean (mention any two of the 5 things)?
–Centralization
–Pipe movement and fluid velocity (looking for turbulence)
–Spacer design
–Rheology properties of mud
–Other specific issues to a cement job.
what is another important point on completion type.
Whoever is doing the completion has to get in the middle of the primary cementing practices!!!
Name at least 3 of the 9 different types of completions
Openhole completion
Perforated casing completion
Single selective completion
Multiple selective completion
Dual string completion
Gravel pack completion
Monobore completion
Horizontal Completions
Other
Name two advantages of open hole completions
Advantages
� All the pay interval is open to flow
� The full wellbore diameter is open to flow.
� The well may be easily worked over or deepened.
�Very Inexpensive
what are open hole completion disadvantages?
Disadvantages
� wellbore stability problems
� lack of zonal control
� crossflow and/or poor vertical sweep efficiency
what are applications of open hole completions?
Applications
�Fractured Carbonates and Chalks � Austin Chalk
�Flowdrilling
�Coal Bed Methane Completions
�Horizontal Wells
what do open hole completions must have?
Must have wellbore stability
May place a slotted liner in well just to make sure that during cleanout operations you do not sidetrack the well=
what are openhole completions friendly to?
Very friendly to underbalanced completions
what are the advantages of peforated casing completions (mention 2 out of 4)?
Advantages
–Zonal isolation possible
–low cost
–simple
–flexibility for future workover operations
what are the disadvantages of peforated casing completions ( (mention 2 out of 4))?
Disadvantages
–completion costs (such as cementing and perforating) are significant compared to an open hole completion
–must have a good cement job
–No subsurface control equipment
–Nothing to protect casing from damage (such as tubing!!)
what applications of perforatied casing completions (mention 2 out of 3)?
Dry gas production up casing � Hugoton Field
�Dry gas production with some liquids up velocity string
�Rod pump wells
What are two interesting facts about single selective completions
It incorporates a single production tubing string run in the well with a packer above the perforations.
It is the most common type of completion run in the industry on wells that will naturally flow.
where is single seelctive completion used?
Mention two sepeerate regions
It is used in both gas well completions (Wilcox, S. Texas; Cotton Valley, E. Texas) and for oil wells (throughout West Texas, Alaska etc)
What are 2 out of 5 advantages of single selective completion?
Advantages
�It can enable effective liquid production by correctly sizing the tubing to the reservoir deliverability,
�Equipment may be included for a variety of artificial lift techniques,
�Protects casing from corrosion or stimulation pressures.
�It readily allows for restimulation of the well
�The tubing can also incorporate additional safety devices such as Sub-Surface Safety Valves (SSSVs). These valves are typically required by regulatory authorities for all offshore wells and on Alaskas north slope
what are 2 out of 3 disadvantages of single seelective completion?
Disadvantages
�Additional Cost
�Complexity
�Limit fracture stimulation pumping rates
Why should I run a packer (mention two out of 6 reasons)?
Reasons for running a packer include:
- Isolation of well fluids and pressures;
- Keeping gas mixed with liquids to assist with production;
- Separation of producing zones;
- Formation of an annular hole section for gas lift injection or subsurface hydraulic pumping systems;
- Safety - providing better well control; and
- Holding well service fluids (such as kill weight fluids) in casing annulus.
Mention info about permanent packers
they can only be removed by being milled out
•they can withstand large differential pressures
mention info about retrivable packers
they can be removed through tubing movement
�may be very difficult and expensive to mill out
�have more moving parts, with more leak paths
what could a liner completion be used for?
A liner (a casing string not run to the surface) could be used for the final external pipe string due to reservoir pressure and lost circulation problems in drilling the well.
name 2 out of four facts of dual string completions
This type of completion (sometimes referred to as a parallel string completion) is a variant on the multiple selective completion.
It is used when there is distinctly different producing characteristics between the two productive zones such that they cannot be effectively commingled.
This includes cases where different leasing and pooling agreements exist for different formations.
Having separate tubing strings for each zone allows separate management and accounting of the two formations.
What is a gravel pack used for in the well across the entire perforated well?
Completion of a well in an unconsolidated formation requires a technique to prevent production of the formation material with the reservoir fluids.
what is gravel pack completion made of?
The pack consists of a perforated/slotted tubing around which is placed well sorted sand which is correctly sized to prevent production of formation sand.
what is advantage of gravel pack completion, mention two out of three?
–Ability to segregate unwanted sand production insitu
–Protection of wellbore for formation void effects on casing structural integrity.
–Prevention of surface equipment damage and separation equipment fill up.
what is disadvantage of gravel pack completion , metnion two out of three?
–Large skin factors of 20-30 are inherent.
–Expensive
–Complexity in multiple completions
mention stages of sliding sleeves with isolation packes
- Completion string, consisting of sliding sleeves and packers, is run into well.
- Packers are exposed to hydrocarbons and swells to create seal with wellbore.
- First zone is stimulated.
- Ball is dropped and second zone is stimulated.
- Larger diameter ball is dropped and third zone is stimulated.
- process can be repeated 30 times.
