CASING PROPERTY ANALYSIS IN DEEP AND ULTRA DEEP WELLS

In conventional casing string design,only casing strength is considered.While in the development of some deep wells,ultra-deep wells and high pressure gas wells,new requests arise.More specifically,the casing must obtains gas sealing property,higher temperature tolerance,and sufficient tension strength and compressing strength for the coupling.In addition,the cement ring should enhance casing strength.By theoretical interpretation,finite element calculating,and large scale tests in kind,the casing properties in deep and ultra-deep wells were analyzed,with some valuable data and conclusions obtained.It points out that tests in kind simulating the deep and ultra-deep well conditions is an effective way to testify the casing properties.Combining with casing string design,a set of casing selection method was proposed,which is also suitable for tubular string design.