UNIVESITY COLLEGE OF ENGINEERNG(A), JNTU KAKINADA

DEPARTMENT OF PETROLEUM ENGINEERING AND PETROCHEMICAL ENGINEERING III B Tech 2nd Semester; Petroleum Engineering

Lab External Examination Subject: Drilling Simulation Laboratory

Date: 05-06-2014 Max. Marks: 40 Paper Setter: Kishore Javvaji Time: 180 min

Answer any one of the following questions and simulate it using MATLAB to compare the accuracy.

1. a) i. An 8 1/2 hole is drilled to 8000ft using mud with a density of 12 ppg. If the formation

pore pressure at this depth was 4700 psi what would be the mud pressure overbalance, above the pore pressure.

ii. If the mud density were 10 ppg what would be the overbalance? iii. If the fluid level in the annulus in a. above dropped to 200 ft due to inadequate hole fill

up during tripping, what would be the effect on bottom hole pressure?

b) Determine the total depth that can be reached with a specific bottom hole assembly for the following data:

Drill pipe: 21.871 lb/ft Tensile strength: 554000 lb BHA weight in air: 50000 lb BHA length = 500 ft Margin of over pull: 10000 lb Mud weight: 13.5 ppg Safety factor: 10%

2. While drilling a 8 -in hole section of a well the mud pit level indicators indicate that the well is flowing. when the well is made safe the following information is collected:

Drill pipe pressure = 200 psi Casing Pressure = 250 psi

Pit gain = 40 bbls Using this data and the information provided in data sheet, carryout the necessary calculation out the necessary calculation to determine:

i. a) The formation pressure b) Kill mud weight c) Time to kill the well

ii. Nature of influx

Data Sheet