Drilling Engineering 1

1. Calculate the pull force for the following well information 

• Drill collar outer diameter: Dop = 6.0 in.

• Hole diameter: Dh = 9.0 in.

• Mud cake thickness: tmc = 2/32 in.

• Coefficients of friction: 0.15, for oil-based mud; 0.25, for water-based mud

• Length of drill collar embedded in mud cake: Lep = 20 ft = 240 in.

• Differential pressure: ΔP = 500 psi

2. Calculate Free Point constant and stuck depth for the following well data

5" Tubing 9.5 lb/ft ID= 2.992", 20" stretch with 25000 lb pulling force.

3.Calculate the slurry density of Class G cement mixed with 45% fresh water. How much water is required for mixing 100 sacks?

4. What is the density and yield of the following slurry: Class G (1 sack) + 35% silic flour

plus 2% fluid loss additive (absolute volume = 0.0932 gal/lb) plus 44% water.

             Absolute vol

Bentonite 0.0454

Silica Flour 0.0454

FL Additive 0.0932

 5. Calculate the amount of water per sack required to provide a slurry of 13.0 ppg for a slurry consisting of Class G cement + 8%  Bentonite.

6.Calculate the cement volumes for a 13 3/8" casing using the following data:

• subsea well with seabed at 450 ft below Rotary Table (BRT)

• 16" hole (not 17.5")

• Total Depth (TD) is at 6000 ft MD

• 13 3/8" shoe at 5980 ft measured depth (MD)

• 13 3/8" casing is N-80,72 lb/ft, ID = 12.347 in

• 20" shoe at 2000 ft MD

• 20" casing is K55,133 lb/ft, ID = 19.73 in

• Top Of Cement (TOC) to be 500 ft inside 20" casing shoe

• Tail slurry to extend 500 ft above the 13 3/8" shoe

• The shoe track consists of 1 joint.

• 5" rillpipe, 19.5 lb/ft is used as the running string

You are required to base cement volumes on open hole volume plus 30% excess.

Slurry details

Lead Slurry

• Class G cement + 0.3 gals/sk extender + 0.2 gals/sk retarder + 11.35 gals/sk

seawater.

• Yield = 1.99 ft3/sk

• Density = 13.0 ppg

Tail slurry

• Class G cement + 0.05 gals/sk retarder + 0.05 gals/sk dispersant + 4.8gals/sk

freshwater.

• Yield = 1.13 ft3/sk

 7.  Hole depth = 13,900 ft

             Hole size = 8.5 in

             Casing Shoe = 13,891 ft

            Mud weight = 11.6 ppg

            Casing dimensions= OD/ID = 7 in/6.184 Grade C95 29#

            Cement = cement column should be 6,562 ft long, as follows:

            From shoe to 656 ft, use API Class G cement

            From 656 ft to 6,562 ft, use API Class H cement with 2% bentonite and 0.3% HR-4

(Note: HR-4 is a type of cement retarder)

To prevent contamination of cement by mud, 30 bbl of fresh water should be pumped ahead

of the cement.

• Allow 15 min for release of plugs

• Shoe track: 80 ft

Calculate:

1) quantity of cement from each class;

2) volume of mix water;

8.   Inhibition by KCl muds is explained by which process

a    Clouding b. Ion Substitution c. Temperature difference d. encapsulization

9. PHPA muds inhibition is done by

a.      Clouding b. Ion Substitution c. Temperature difference d. encapsulization

 10.What is the temperature and pressure applied for an API Filter Press

a.      100 F, 100 psi b. 100 C, 100 psi c. 27 C, 100 psi d. 27 F, 100 psi

 11.What is the operating T & P for HPHT Filter Press

a.      >200 F, 500 psi  b. >100 C, 1000 psi c. <200 F, 500 psi d. 100 F, 1000 psi

 12.  MBT Indiacates

a.      Solid content in the mud b. HGS in Mud c. LGS in Mud d. Cation exchange capacity

13.  Centrifuge efficiency is depend on

a.      Bowl Speed b. Bowl conveyer differential speed c. pool depth d. feed flow rate e. all of the above

14.    The corrected API Filter loss (30 min) for a water based mud was determined as 10 cc. at a temperature of 860 F. What would it have been at 1400F and 2120F?

15.    Mud is contaminant with cement which of the following additive is recommended to add

            HCL 2. SAPP 3. H2SO4 4. Lime

16. Please use the following information to determine annular velocity, cutting slip velocity, net rise velocity, and tell us if the flow rate is good for hole cleaning.

Flow rate = 180 gpm Hole Diameter = 7.5 inch Drillpipe OD = 4.5 inch PV = 12 cps

MW = 9.8 ppg Diameter of cutting = 0.40 inch Density of cutting = 22.0 ppg

17. Determine the pressure loss in the drill string based on the following information

Drill pipe length = 5000 ft ID of drill pipe = 3.34 inch Drill collar length = 500 ft ID of drill collar = 2.8 inch Mud Weight = 9.5 ppg Plastic Viscosity = 12 centipoise Flow rate = 600 gpm

Current Mud Weight = 12.5 ppg Well TVD = 9000 ft

18. The well information is listed below:θ300 = 85 θ600 = 130 Hole diameter = 9 inch Drill Collar = 6.25 inch ID of drill collar = 2.5 inch Drillpipe diameter = 5 inch ID of drill pipe = 3.5 inch Average pipe running or pulling speed = 250 ft/min Drill Pipe Length = 12000 ft Drill Collar Length = 800 ft

Cal. P Loss around Drill Pipe and Drill collars.

19.  Fann VG Meter reading of a mud are 12 and 20 at 300 and 600 RPM. Calculate plasitic Viscosity (μP), Apparent Viscosity (μA), Bingham Yield Point (Yp), True Yield Point (Yt), Flow Behavior index (n) and Consistency index (K) of the fluid.

20. What is the slip velocity of a 0.5 inch diameter sphere under laminar flow in a 30 cP, 10 ppg mud. Assume ρs = 21.7 ppg. What will be maximum falling rate for the system in turbulent flow ignoring wall effect ? What is corrected slip velocity corrected for wall effect if dh = 8 inch and dp = 4.5 inch ?