Difficulties and Countermeasures of Completion for HT/HP Gas Wells

For gas wells with high temperature,high pressure and rich H_3S,the geological condition is very complicated.Both risk and efficiency are the important consideration when well completion. So,it is necessary to formulate some relative countermeasures to overcome a certain difficulties existing in completion.In this paper,some completion technologies for these wells at home and abroad are investigated.It is considered that the main difficulties include obvious conflict between safety and economy,continuous leakage and plugging failure,complicated working status and downhole condition,high requirement for facility property.However, there are some countermeasures,for example,the packer completion, casing tie back,heavy casing,complex casing string,special screw connector,anti-sulphur wellhead,downhole safety valve can be applied to increasing the wellbore safety;and the anti -sulphur material and inhibitor can also increase the corrosion resistance;as a result,the safety during operation can be increased by whole management of wellbore and well control.