水合物藏钻探中的环空多相流溢流特性研究  

Study on Annular Multiphase Flow Characteristic of Gas Kick During Hydrate Reservoir Drilling

作　　者：王志远[1] 孙宝江[1] 高永海[1] 马永乾[1] 宋荣荣[1] 

机构地区：[1]中国石油大学(华东)石油工程学院,山东东营257061

出　　处：《应用基础与工程科学学报》2010年第1期129-140,共12页Journal of Basic Science and Engineering

基　　金：国家"863"计划重大项目课题"深水钻完井关键技术"(2006AA09A106);教育部博士点基金"深水钻井井控水力参数计算理论"(20060425502);国家自然基金;含天然气水合物相变的三相多组分多相流动理论(50874116)

摘　　要：含天然气水合物相变的环空多相流动问题是天然气水合物藏钻探过程中井筒流体力学问题的一个关键.考虑天然气水合物的相变,建立了溢流期间环空各相流体的连续性方程、动量方程以及能量方程.模拟计算结果表明:溢流期间,天然气水合物的生成区域会随着循环流量的增大或抑制剂浓度的提高而减小,可通过增大流量和抑制剂浓度使水合物的生成区域脱离海底,减小防喷器管线被堵塞的危险;水合物的生成使环空中气体体积分数降低,泥浆池增量减小,给溢流检测带来延迟;当检测到有气侵发生时,水合物藏分解速率比较小时,井筒中生成水合物的可能性要比分解速率大的情况下更为严重;水合物相变对井底压力的影响较小,在工程中计算井底压力时可以忽略;由于天然气水合物的生成使得关井套压值不能真实反应气侵情况,而且随着时间的增加情况会更加严重.The annular multiphase flow, considering nature gas issue to wellbore hydrodynamics during hydrate reservoir hydrate phase transition, is the key drilling. The conservation of mass equations, momentum equation and energy equations are established considering of nature gas hydrate phase transition during gas kick. The conclusions can be drawn through numerical simulation： The hydrate-forming region becomes small with increasing circulation rate and inhibiter concentration, and it is possible to make the hydrate-forming region away from sea floor by increasing circulation rate and inhibiter concentration, thus preventing blowout preventer lines from hydrate plugging; the decrease in gas volume fraction in the annulus due to hydrate formation reduces pit gain, which can delay the detection of well kick; the possibility of hydrate presence at a relatively low gas production rate is much greater than that at a relatively higher production rate; the bottom hole pressure is affected little by hydrate phase transition, and it is allowable not to consider hydrate phase transition when the bottom hole pressure is calculated ; shut-in casing pressure cann＇t truly reflect gas kick due to hydrate formation and the situation is getting worse with time

关 键 词：环空多相流 相变 天然气水合物 溢流 

分 类 号：TE22[石油与天然气工程—油气井工程] P618.13[天文地球—矿床学]