A system for designing a casing string for an oil well, a gas well, an oil and gas well, and/or a geothermal well. The system comprises a processor, a non-transitory memory storing a casing string design, wherein the casing string design comprises at least one section of UOE-type pipe, a downhole environment simulation application stored in the non-transitory memory that, when executed by the processor determines downhole conditions based on the casing string design, wherein the downhole conditions comprise a downhole temperature, and a casing collapse strength modeling application stored in the non-transitory memory that, when executed by the processor, analyzes collapse strength of the casing string based on the downhole temperature and based on a UOE-type pipe collapse strength model and presents a collapse strength report on the casing string design based on analyzing the collapse strength of the casing string.