I In order to attempt lifting crude oil and natural gas from reservoir to the surface, every Oil&Gas companies have to do dilling operation. The object of drilling operation is to create a hole from the reservoir untill the surface as a path for the fluids flowing from the reservoir to the surface. But, the cost incurred to perform the drilling operations wasn’t a little even we could categorize it as a very expensive work. Therefore, to pushing low the budget of drilling opertion, we have to make a good planning before the operation was started. One of the aspect from the drilling operations that we have to give attention is design of the casing. A good planning of casing design is very important for this operation. Because it’s in directly related to the safety factor of the operations, and also related to the drilling cost. As we know the cost for casing, is one of the most expensive part in drilling operations which is will be influence for the final cost of the drilling opertions. So that, a good planning and a precise calculating is really necessary. Right before deciding to choose wich casing that we want to apply in the well each traject. In this final assignment I am as the writter will evaluating the planning of the casing design on wells A-3 and A-5 from BNWT. The methodes used for the calculating in this final assignment in maximum load methode. This final assignment was expected to could be used as a refference and consideration to evaluate a good and safe casing design planning.