高温高压井套管多环空压力体积耦合分析  

Analysis of Multiple Casing Annulus Pressure Buildup for HTHP Wells

作　　者：窦益华[1] 薛帅[1] 曹银萍[1] 

机构地区：[1]西安石油大学机械工程学院

出　　处：《石油机械》2016年第1期71-74,共4页China Petroleum Machinery

基　　金：国家科技重大专项"超深超高压气井油套管柱安全评价与控制技术研究"(2011ZX05046-7)

摘　　要：生产过程中,高温高压井套管环空温度上升,加热密闭环空液体,导致套管外载增大,威胁套管的安全。鉴于此,考虑多个套管环空压力体积耦合效应,基于Lame厚壁筒公式,建立了内外压作用下套管径向位移方程,分析了不同温差下套管径向热膨胀、套管径向压缩、环空流体热膨胀和环空流体压缩引起的环空体积变化量;依据PVT状态方程,建立了多环空的压力体积耦合计算模型,分析了典型高温高压井B、C密闭环空的压力。计算结果表明,随着温度的升高,B环空受热膨胀,引起C环空体积减小、压力升高;环空温度每升高10℃,B环空的压力上升5.3 MPa,C环空的压力上升5.7 MPa,与试验测量数据4.9 MPa较接近;随着温度升高,C环空压力增幅明显大于B环空。研究结果可以为套管环空压力管理提供依据,确保生产过程中井筒完整性。In the production process,the HPHT casing annulus temperature rises,heats the sealed annulus fluid,leading to increased casing load which could threatens the casing safety. To address the issue,on the basis of Lame thick-wall cylinder formula,the equation of the casing radial displacement under the internal and external pressure has been established considering the multiple casing annulus volume-pressure coupling effect. The casing volume changes caused by the casing radial thermal expansion,casing radial compression,annulus fluid thermal expansion and annulus fluid compression under different temperature difference have been analyzed. Based on the PVT equation of state,a multiple annulus volume-pressure coupling calculation model has been established to analyze the typical HPHT well's B,C sealed annulus pressure. The results show that,as the temperature rises,the B annulus has been thermally expanded,causing volume reduction and pressure increase of the C annulus. With each10 ℃ increase of annulus temperature,the B annulus pressure raises 5. 3 MPa,and the C annulus pressure raises5. 7 MPa,which are close to the experimental measurement of 4. 9 MPa. With the increase of temperature,the C annulus pressure increase was significantly greater than the B annulus. The results could provide bases for the casing annulus pressure management to ensure the wellbore integrity during production.

关 键 词：套管 环空压力 高温高压 耦合模型 压力预测 

分 类 号：TE244[石油与天然气工程—油气井工程]