For the purpose of this example we will use a drill string with the following components:
� 560 m of 4-inch drill pipe with a 4-inch FH thread top and bottom
� A BHA which is composed of the following:
o An 8 inch diameter, 0.5 m long bit sub with a 6.625 API top thread and a 7.625 inch bottom thread
o An 6.5 inch diameter, 1.09 m long crossover with a 4.5 inch IF top thread and a 6.625 inch API bottom thread
o An 6.5 inch diameter, 18.63 m long Drill collar with a 6.625 inch API top and bottom thread
o An 6.5 inch diameter, 0.52 m long crossover with a 4 inch IF top thread and a 4.5 inch IF bottom thread
o 64m of heavy weight drill pipe
� A 9.5 inch Baker PDC drill bit (model number HCR-605)
In SDS, we would create an entry in the Drill_String class. We would then create an entry in the appropriate class for each component and then "compose" the drill string of these components. Since we want to note the different types of thread that are on each component, then we would also create 2 facility_connector records for each component.
Facility_Composition
The class Facility_Composition allows you to define the composition of an assembly by defining its components. You can also describe the order in which they are composed by using the attribute Linear_Sequence. The convention used in drilling is that the first item to go in the hole is component #1, the second #2 etc.