气体钻水平井井径扩大环空流动特征的数值模拟  

Numerical simulation on the annulus diameter expansion in gas drilling horizontal well

作　　者：万里平[1] 孟英峰[1] 魏纳[1] 金雪梅 李孝军[1] 张华 

机构地区：[1]西南石油大学"油气藏地质及开发工程"国家重点实验室,成都610500 [2]川庆钻探安全环保质量监督检测研究,广汉618300 [3]西南油气田分公司蜀南气矿,泸州646001

出　　处：《应用力学学报》2011年第5期543-546,560,共4页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金(50974106)

摘　　要：由于气体钻水平井中岩屑受力状态与直井有很大不同,特别是遇到井径扩大,更是携岩的关键点。因此,在分析了气体钻水平井岩屑运移特点以及建立环空连续性方程和动能方程的基础上,以实际井为例考虑了不同井径扩大率,数值模拟了其扩径段气固两相的流动状态,包括气固速度、岩屑浓度、压力分布等。研究结果表明:气体在经历扩径段时环空压力有个降落又回升的过程,随着井眼扩径系数的增大,压力下降又回升,所经历的长度会逐渐增长;扩径系数大于一定值时,扩径变径处存在一定区域的零流动区;扩径系数越大,低速区和回流区就越大越长,扩径下部区域越容易堆积岩屑,填充井眼。The stress state of the gas drilling horizontal wells is very different from that of vertical wells,especially in face of hole enlargement,so it is the key point for carrying rocks.In this paper,the annular continuity equation and the momentum equation are established.Taking the actual well as an example,different hole enlargement rates are considered,the expanding gas-solid flow state is numerically simulated.The results show that: when passing through the gas annulus,the gas pressure experiences a descending and a recovery processes,with the increasing of the hole expanding coefficient,the pressure drops first and then rise again,the length experienced by the gas will gradually increase;when expanding coefficient exceeds a certain value,there exists certain zero flow zone in the expanding area;the larger the expanding coefficient is,the longer the low-speed zone and the recirculation zone are,the easier is to fill the hole.

关 键 词：气体钻水平井 井径扩大 关键点 气固两相流动 

分 类 号：TE2[石油与天然气工程—油气井工程]