Papers by Author: Wen Fei Li

Abstract: PuGuang gas field is an acid gas field because of its high level of H2S and CO2, so it is important to evaluate its reliability of casing to make sure the safe exploiting. Based on the analysis of casing load mechanism, calculation model is researched. According to reliability theory, regard the casing as a series system, and consider the failure types of casing in acid gas field, reliability model of casing parts and whole are proposed. The analysis results show that reliability of whole casing of P101-2H well is 100% in the early days of exploitation, and casing design is right. Because some factors including corrosion, perforating and so on decreased the strength of casing, reliability of whole casing is decreased after 10 and 20 years.

Abstract: According to the geostress and casing structure data of Puguang gas field，mechanics and deformation law of nonstandard casing is studied on condition of non uniformity and high geostress. The results show that collapse strength has increased 51.75 MPa（270%）as thickness raise from 8.98 mm to 15.11 mm under uniform external loads. Under the nonuniform external loads, the collapse strength of casing has reduced 60% in some degree such as thickness is 13.84 mm. Application in site proves that nonstandard casing is feasible, which is significant for safe and efficient exploit in Puguang gas field.

Abstract: In the low-pressure pulse and cavitation jet compound drilling technology, pulse low-pressure and cavitation jet generator is installed on bit, water jet modulated by generator can generate pulse low-pressure, which will alternate rock mechanics, decrease rock breaking strength, increase rock-breaking efficiency. And cavitation jet generated can increase hydraulic power downhole. The results show that low-pressure pulse and cavitation jet generator has been run well from 5349m to 6162m for 129.36h-136.63h in TK1090 well, increasing drilling speed 40.6%～85.1%. The low-pressure pulse and cavitation jet compound drilling technology can increase drill speed and be deployment in deep well drilling.