摘要
针对蒸汽吞吐时发生汽窜、地层出砂及水泥环破裂掏空的情况,利用ANYSIS有限元分析的数值模拟,对井筒热应力和热膨胀进行了分析。注蒸汽井间发生汽窜时,易诱发地层出砂,最大热应力都发生在套管内壁,且超过了N80套管的热弹性屈服极限,最大热膨胀都发生在温度变化过渡区,是诱发热采井套管变形损坏的主要原因。套管周围地层掏空时,其热应变达到了2%,远超过材料弹性极限应变的0.3%,是热采井套管变形损坏的主要原因。提出套管保护对策,并开展了4项相应防治技术先导试验,取得了较好的保护套管效果,形成了稠油热采井套管保护配套技术。
Thermal stress and expansion of wellbore are analyzed through ANYSIS finite element analysis in accordance with the problems of steam channeling,sand production and broken and bailed cement sheath.Steam channeling between wells tends to induce sand production.The maximum thermal stress occurs on inside casing wall and exceeds the themoelasticity yield limit of N80 casing.The maximum thermal expansion occurs in temperature transition zone and is a reason of casing deformation and failure in thermal wells.When the formation around casing is bailed,thermal strain reaches 2%,far more exceeding the elastic limit strain of 0.3% of the material,and is another reason of casing deformation and failure in thermal wells.4 pilot tests on casing protection have been carried out and achieved good result.
出处
《特种油气藏》
CAS
CSCD
2007年第6期83-86,共4页
Special Oil & Gas Reservoirs
关键词
稠油热采
应力场
有限元法
套管损坏
防砂
heavy oil thermal recovery
stress field
finite element
casing failure
sand control
