Formation Pressure Assignment 1. A formation is to be hydraulically fractured at the depth of 10000 ft. The drilling mud has a SG of 0.85. If the formation breaks down at 80% of theoretical overburden pressure, what pump pressure will be required to break the formation? 2. A formation has a pressure of 4000 psi at 7500 ft. The operator desires to have a safety allowance of 300 psi opposite the formation, what would be the required mud density? 3. The following table is obtained from a well drilled at Alpha field. Assuming the normal formation pressure of 9.0 ppg: a. Make a plot of d-exponent vs. depth using Cartesian coordinates b. Make a plot of d-exponent vs. depth using semi-log c. Make a plot of modified d-exponent vs. depth using Cartesian coordinates d. Make a plot of modified d-exponent vs. depth using semi-log e. Determine the depth of upper zone of abnormal pressure f. Can the d-exponent be used to determine the abnormal pressure in this case? Give your reasons Depth Bit size Drilling time (ft) (in.) (hrs) WOB (lb) N Mud density (rpm) (ppg) 6,000 8.500 4.72 35,000 120 9.0 6,500 8.500 4.85 35,000 120 9.0 7,000 8.500 6.50 35,000 110 9.0 7,500 8.500 7.58 35,000 110 9.0 8,000 8.500 11.21 30,000 110 9.4 8,500 7.875 10.87 30,000 110 9.4 9,000 7.875 12.69 30,000 110 9.4 9,500 7.875 14.28 30,000 110 9.8 10,000 7.875 6.49 30,000 110 10.1 10,200 7.875 7.61 30,000 100 10.1 10,400 7.875 8.10 30,000 100 10.1 10,600 7.875 8.62 30,000 100 10.5 10,800 7.875 9.17 30,000 90 11.1 11,000 7.875 10.47 30,000 90 11.1 11,200 7.875 11.17 30,000 90 11.3 11,400 7.875 11.91 30,000 90 11.6 11,600 7.875 9.13 35,000 90 11.6 11,800 7.875 9.71 35,000 90 11.8 12,000 7.875 9.71 35,000 90 13.1 12,200 7.875 10.00 35,000 90 13.4 12,400 7.875 11.11 35,000 90 13.6 12,600 7.875 11.11 35,000 90 14.2 12,800 7.875 11.77 35,000 90 14.5