Study On Segregated Completion And Segregated Steam Injection Technology For Horizontal Wells

Steam injection is one of the main production technologies for heavy oil horizontal wells.At present,most of horizontal wells adopt screen completion and commingled steam injection.Affected by anisotropic layer and surrounding injector producer wells,it is easy to cause producing uneven in horizontal section.Moreover,it limits the implementation of subsequent process measures,such as segregated steam injection,segregated water shutoff,sealing channeling,etc.In view of this problem,I carried out study on segregated completion and segregated steam injection technology for horizontal wells.Based on the investigation and analysis of the research status of the technology at home and abroad,and combine with the production characteristics of Liaohe Oilfield,I designed the string of segregated completion and segregated steam injection for horizontal wells.The main idea of this technology is that running high temperature external casing packer and thermal casing centralizer in the process of completion.According to the well drilling data,geological data and other related information,choose the appropriate separate position,and separate horizontal section by using high temperature external casing packer.The thermal casing centralizer can ensure the whole string in the middle to improve the reliability of sealing.Steam umbrella is used to separate casing tubing annul of horizontal section when running steam injection string.Tubing centralizer can make the string center as much as possible to ensure the sealing effect of steam umbrella.Segregated steam injection valve is selected in appropriate position in each section,and the steam injection volume of each section is reasonably distributed according to the test data.In the process of research,I developed its main supporting tools,including high temperature external casing packer,thermal casing centralizer,steam umbrella,tubing centralizer and segregated steam injection valve.Through theoretical calculation and a large number of laboratory tests,I constantly improved the tool structure,so that its technical parameters can meet the field demand.In addition,I developed a supporting steam injection analysis software,which can be used to design steam distribution and calculate the hole diameter of steam injection valve according to steam injection working condition and parameters.Up to now,the technology has carried out 164 Wells in Liaohe Oilfield,and the cumulative incremental oil production reaches 10.08x10~4t.Field application shows that the string has good mechanical performance,and it is safety and reliability with remarkable effect.The technology can effectively solve the problem of uneven utilization of horizontal sections,which has good application prospect and economic benefit.