A 15-in. hole is drilled to a depth of 4,000 ft. The API water loss of...

 

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A 15-in. hole is drilled to a depth of 4,000 ft. The API water loss of the mud is 10 mL. Approximately 30% of the lithology is permeable sandstone and the rest is impermeable shale. a) Construct a plot of estimated filtration loss in barrels vs. time in hours (0 to 24 hours) that would occur if the hole were drilled instantaneously. Assume porosity is 0.25. b) Compute the radius of the invaded zone for Part a in inches after 24 hours. c) Repeat Part a assuming a drilling rate of 200 ft/hr. d) Do you feel the API water loss test is representative of conditions in the well during drilling operations? (Hint: Find an article on "dynamic filtration".) A 15-in. hole is drilled to a depth of 4,000 ft. The API water loss of the mud is 10 mL. Approximately 30% of the lithology is permeable sandstone and the rest is impermeable shale. a) Construct a plot of estimated filtration loss in barrels vs. time in hours (0 to 24 hours) that would occur if the hole were drilled instantaneously. Assume porosity is 0.25. b) Compute the radius of the invaded zone for Part a in inches after 24 hours. c) Repeat Part a assuming a drilling rate of 200 ft/hr. d) Do you feel the API water loss test is representative of conditions in the well during drilling operations? (Hint: Find an article on "dynamic filtration".)