6.20 The data in Table 6.23 were taken in shale on a well drilled in south...

 

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6.20 The data in Table 6.23 were taken in shale on a well drilled in south Louisiana. a. Using the short-interval drilling data of Table 6.23 between 10,000 and 10,050 ft, estimate values for as. a6, a7, and ag. Answer: 0.9; 0.5; 1.2; and 0.3. b. Make a plot of penetration rate vs. depth, using Cartesian coordinates. c. Make a plot of d-exponent vs. depth using Carte- sian coordinates. d. Make a plot of modified d-exponent vs. depth us- ing Cartesian coordinates. e. Make a plot of drillability parameter K, vs. depth using Cartesian coordinates. f. Make a plot of modified drillability parameter Kp vs. depth using Cartesian coordinates. (Note decrease in Kp between 10,040 and 10,050 ft due to mud weight increase.) g. Make a plot of pore pressure vs. depth using the method of Rehm and McClendon and the modified d- exponent plot. h. It is known that the pore pressure at 11,000 ft is 11.5 lbm/gal. Compute a value for a3 using this known pressure point. Answer: 120x106. i. Make a plot of pore pressure vs. depth using pore pressures computed from the modified K, parameter plot. j. Do you think the mud density should be increased before the next sand is drilled? Answer: Yes. 6.20 The data in Table 6.23 were taken in shale on a well drilled in south Louisiana. a. Using the short-interval drilling data of Table 6.23 between 10,000 and 10,050 ft, estimate values for as, a6, a7, and ag. Answer: 0.9; 0.5; 1.2; and 0.3. b. Make a plot of penetration rate vs. depth, using Cartesian coordinates. c. Make a plot of d-exponent vs. depth using Carte- sian coordinates. d. Make a plot of modified d-exponent vs. depth us- ing Cartesian coordinates. Depth (ft) 5,000 6,000 7,000 8,000 9,000 10,000 10,010 10,020 10,030 10,040 10,050 11,000 12,000 13,000 TABLE 6.23-PENETRATION RATE DATA FOR EXERCISE 6.20 Hydraulic Parameter Ratio (fraction) Penetration Rate (ft/hr) 26.6 32.5 11.6 28.0 24.8 6.4 2.9 8.2 10.0 8.0 12.1 9.3 19.0 13.1 Bit Weight (1,000 lbm) 40 40 30 55 60 50 20 20 20 20 50 50 30 20 Bit Size (in.) 9.875 9.875 9.875 9.875 9.875 9.875 9.875 9.875 9.875 9.875 9.875 9.875 50 50 6.5 6.5 Rotary Speed (rpm) 66 60 42 84 90 60 60 60 90 90 60 60 60 42 Tooth Wear (fraction) 0.6 0.2 0.5 0.3 0.0 0.9 0.9 0.0 0.0 0.0 0.0 0.8 0.0 Oc 0.5 1.150 1.100 1.050 0.950 0.900 0.850 0.850 0.850 0.850 0.400 0.850 0.800 0.750 0.700 ECD (lbm/gal) 9.5 9.5 9.5 9.5 10.5 11.0 11.0 11.0 11.0 11.0 12.0 12.0 14.0 14.2 6.20 The data in Table 6.23 were taken in shale on a well drilled in south Louisiana. a. Using the short-interval drilling data of Table 6.23 between 10,000 and 10,050 ft, estimate values for as. a6, a7, and ag. Answer: 0.9; 0.5; 1.2; and 0.3. b. Make a plot of penetration rate vs. depth, using Cartesian coordinates. c. Make a plot of d-exponent vs. depth using Carte- sian coordinates. d. Make a plot of modified d-exponent vs. depth us- ing Cartesian coordinates. e. Make a plot of drillability parameter K, vs. depth using Cartesian coordinates. f. Make a plot of modified drillability parameter Kp vs. depth using Cartesian coordinates. (Note decrease in Kp between 10,040 and 10,050 ft due to mud weight increase.) g. Make a plot of pore pressure vs. depth using the method of Rehm and McClendon and the modified d- exponent plot. h. It is known that the pore pressure at 11,000 ft is 11.5 lbm/gal. Compute a value for a3 using this known pressure point. Answer: 120x106. i. Make a plot of pore pressure vs. depth using pore pressures computed from the modified K, parameter plot. j. Do you think the mud density should be increased before the next sand is drilled? Answer: Yes. 6.20 The data in Table 6.23 were taken in shale on a well drilled in south Louisiana. a. Using the short-interval drilling data of Table 6.23 between 10,000 and 10,050 ft, estimate values for as, a6, a7, and ag. Answer: 0.9; 0.5; 1.2; and 0.3. b. Make a plot of penetration rate vs. depth, using Cartesian coordinates. c. Make a plot of d-exponent vs. depth using Carte- sian coordinates. d. Make a plot of modified d-exponent vs. depth us- ing Cartesian coordinates. Depth (ft) 5,000 6,000 7,000 8,000 9,000 10,000 10,010 10,020 10,030 10,040 10,050 11,000 12,000 13,000 TABLE 6.23-PENETRATION RATE DATA FOR EXERCISE 6.20 Hydraulic Parameter Ratio (fraction) Penetration Rate (ft/hr) 26.6 32.5 11.6 28.0 24.8 6.4 2.9 8.2 10.0 8.0 12.1 9.3 19.0 13.1 Bit Weight (1,000 lbm) 40 40 30 55 60 50 20 20 20 20 50 50 30 20 Bit Size (in.) 9.875 9.875 9.875 9.875 9.875 9.875 9.875 9.875 9.875 9.875 9.875 9.875 50 50 6.5 6.5 Rotary Speed (rpm) 66 60 42 84 90 60 60 60 90 90 60 60 60 42 Tooth Wear (fraction) 0.6 0.2 0.5 0.3 0.0 0.9 0.9 0.0 0.0 0.0 0.0 0.8 0.0 Oc 0.5 1.150 1.100 1.050 0.950 0.900 0.850 0.850 0.850 0.850 0.400 0.850 0.800 0.750 0.700 ECD (lbm/gal) 9.5 9.5 9.5 9.5 10.5 11.0 11.0 11.0 11.0 11.0 12.0 12.0 14.0 14.2