深层稠油超临界压力注汽管柱设计

Design of Steam Injection Pipe Set for Producing Deep Heavy Oil under Over Critical Pressure

深层稠油油藏埋藏深、注汽压力高、注汽井筒热损失大,同时由于直井中隔热油管的最大下深只有1400m,目前常用的注汽管柱对于埋深超过2000m的深层稠油油藏不能实现全井筒隔热注汽,这会使注汽井筒热损失更大。为了提高深层稠油注汽井井筒隔热效果,在分析了超临界压力条件下深层稠油注汽井的井筒热损失的基础上,研究设计了分段组合式注汽管柱,实现了深层稠油全井筒隔热注汽,井筒热损失小于8%,达到了目前1000m井深油井的井筒隔热水平;设计的注汽配套工具保证了注汽工艺管柱的安全可靠。现场试验表明,深层稠油超临界压力注汽管柱隔热效果好,安全可靠,可以保证深层稠油的注汽质量,满足深层稠油的热采要求。

Because of great depth oi heavy oil reservoir, high steam injection pressure, huge well heat loss, and the only 1400m of maximal setting depth of heat isolating tubing in a vertical well, current normal steam-injection pipes cannot inject steam with heat insulation for deep heavy oil reservoir over depth of 2000m, which makes much more heat loss in steam injection wellbore. In order to improve the heat insulating effect of deep heavy oil well bore, the heat loss of deep heavy oil well bore is analyzed under the condition of super-critical pressure, and the segmented and combined steam-injection pipe string is studied, and the whole well bore heat insulating steam-injection is realized, and the heat loss of the well bore is less than 8%, up to par of the currently heat insulating; the tools of matching steam-injection is designed and the safety & credibility of the steam-injection pipe string arc guaranteed. The experimentation indicates that the heat insulating effect of deep heavy oil super-critical steam-injection is good, in addition, it is safe and credible, so the quality of deep heavy oil steam injection is guaranteed, and the thermal recovery demand of deep heavy oil is met.