Our well is at total depth of 7000 ft and we are going to tr

Our well is at total depth of 7000 ft and we are going to trip out for a bit change. The bottom hole assembly (BHA) is 800 ft long, and weighs 40.000 lb. Estimate How many joints of drillpipe we are using. How many stands of drillpipe the derrickman will rack back when we trip out, if the rig can pull doubles.

Solution

STEP 1

Drillpipe is seamless steel pipe made up in the drill string and it is the major component of the entire drillstring. Typically, 90% – 95% of the total length is drill pipe. Thread connection of drill pipe is called tool joint

STEP 2

Tensile Capacity is in lb.= 40,000 lb

Cross Sectional Area is in square inch.

Yield Strength is in ps

total depth is 7000 ft

bottom hole is 800 ft

no of joints = 7000 /800 = roughly 9 joints

step 5 :

Tensile Capacity = Cross Sectional Area x Yield Strength