Exam 2 completions lecture

Question 1

What is the difference between “hard rock” completion and “soft rock” completion?

Answer 1

A “hard rock” completion does not make any sand, while “soft rock” completion does make sand.

Question 2

what are two distinct charachteristics about packers?

Answer 2

The distinct charactheristics about packers are that they are retrievable and permanent.

Question 3

When does the completion phase of a well begin?

Answer 3

When the bit enters the formation!!!!

Question 4

what happens if skin remains in completion phase of a well?

Answer 4

If the skin remains, a workover is the only way to remove it.

Question 5

what is one important point about completion type

Answer 5

Must allow flexibility of future operations

Need to think of what possible future operations there maybe.

Question 6

what is important point # 2 on completion type?

Answer 6

Must absolutely get a good primary cement job

Planning to do remedial (cure) cementing is poor planning

Question 7

what happens when Completion Begins?

Answer 7

Typical hard rock completion includes running and cementing production casing in place.

Question 8

What does getting a good cement job mean (mention any two of the 5 things)?

Answer 8

–Centralization
–Pipe movement and fluid velocity (looking for turbulence)
–Spacer design
–Rheology properties of mud
–Other specific issues to a cement job.

Question 9

what is another important point on completion type.

Answer 9

Whoever is doing the completion has to get in the middle of the primary cementing practices!!!

Question 10

Name at least 3 of the 9 different types of completions

Answer 10

Openhole completion
Perforated casing completion
Single selective completion
Multiple selective completion
Dual string completion
Gravel pack completion
Monobore completion
Horizontal Completions
Other

Question 11

Name two advantages of open hole completions

Answer 11

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

Question 12

what are open hole completion disadvantages?

Answer 12

Disadvantages

� wellbore stability problems

� lack of zonal control

� crossflow and/or poor vertical sweep efficiency

Question 13

what are applications of open hole completions?

Answer 13

Applications

�Fractured Carbonates and Chalks � Austin Chalk

�Flowdrilling

�Coal Bed Methane Completions

�Horizontal Wells

Question 14

what do open hole completions must have?

Answer 14

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=

Question 15

what are openhole completions friendly to?

Answer 15

Very friendly to underbalanced completions

Question 16

what are the advantages of peforated casing completions (mention 2 out of 4)?

Answer 16

Advantages
–Zonal isolation possible
–low cost
–simple
–flexibility for future workover operations

Question 17

what are the disadvantages of peforated casing completions ( (mention 2 out of 4))?

Answer 17

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!!)

Question 18

what applications of perforatied casing completions (mention 2 out of 3)?

Answer 18

Dry gas production up casing � Hugoton Field

�Dry gas production with some liquids up velocity string

�Rod pump wells

Question 19

What are two interesting facts about single selective completions

Answer 19

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.

Question 20

where is single seelctive completion used?

Mention two sepeerate regions

Answer 20

It is used in both gas well completions (Wilcox, S. Texas; Cotton Valley, E. Texas) and for oil wells (throughout West Texas, Alaska etc)

Question 21

What are 2 out of 5 advantages of single selective completion?

Answer 21

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

Question 22

what are 2 out of 3 disadvantages of single seelective completion?

Answer 22

Disadvantages

�Additional Cost

�Complexity

�Limit fracture stimulation pumping rates

Question 23

Why should I run a packer (mention two out of 6 reasons)?

Answer 23

Reasons for running a packer include:

1. Isolation of well fluids and pressures;
2. Keeping gas mixed with liquids to assist with production;
3. Separation of producing zones;
4. Formation of an annular hole section for gas lift injection or subsurface hydraulic pumping systems;
5. Safety - providing better well control; and
6. Holding well service fluids (such as kill weight fluids) in casing annulus.

Question 24

Mention info about permanent packers

Answer 24

they can only be removed by being milled out
•they can withstand large differential pressures

Question 25

mention info about retrivable packers

Answer 25

they can be removed through tubing movement

�may be very difficult and expensive to mill out

�have more moving parts, with more leak paths

Question 26

what could a liner completion be used for?

Answer 26

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.

Question 27

name 2 out of four facts of dual string completions

Answer 27

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.

Question 28

What is a gravel pack used for in the well across the entire perforated well?

Answer 28

Completion of a well in an unconsolidated formation requires a technique to prevent production of the formation material with the reservoir fluids.

Question 29

what is gravel pack completion made of?

Answer 29

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.

Question 30

what is advantage of gravel pack completion, mention two out of three?

Answer 30

–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.

Question 31

what is disadvantage of gravel pack completion , metnion two out of three?

Answer 31

–Large skin factors of 20-30 are inherent.
–Expensive
–Complexity in multiple completions

Question 32

mention stages of sliding sleeves with isolation packes

Answer 32

1. Completion string, consisting of sliding sleeves and packers, is run into well.
2. Packers are exposed to hydrocarbons and swells to create seal with wellbore.
3. First zone is stimulated.
4. Ball is dropped and second zone is stimulated.
5. Larger diameter ball is dropped and third zone is stimulated.
6. process can be repeated 30 times.