考虑二次梯度项的非牛顿幂律流体试井分析  

Well test analysis of non-Newtonian power-law fluid by the consideration of quadratic gradient term

作　　者：张小龙 

机构地区：[1]中海石油(中国)有限公司上海分公司,上海200335

出　　处：《油气藏评价与开发》2016年第1期29-31,55,共4页Petroleum Reservoir Evaluation and Development

摘　　要：针对传统非牛顿幂律流体试井模型忽略二次梯度项的情况,建立了考虑二次梯度项的无限大地层非牛顿幂律流体试井模型。通过变量代换和Laplace变换,求得了Laplace空间的解析解,利用Stehfest数值反演得到实空间的解,绘制了相应的典型无因次压力曲线版图。分析了二次梯度项对非牛顿幂律流体渗流和试井曲线的影响,发现在井筒储集阶段井底压力几乎不受二次梯度项的影响,但在径向流动阶段随着无因次时间的增加,二次梯度项对井底压力的影响程度将会增大,在生产时间较长时,对于非牛顿幂律流体忽略二次梯度项将会比牛顿流体产生更大的误差,且这种误差随着幂律指数的减小而增大,所获得的结果有利于提高对非牛顿幂律流体渗流规律的认识。The traditional well test model of non-Newtonian power-law fluid neglects quadratic gradient term, so that the well test model of non- Newtonian power- law fluid in infinitely large system considering the quadratic gradient term is established. By means of variable substitution and Laplace transform, its analytic solution in Laplace space and the solution in the actual space utilizing the Stehfest numerical inversion method are acquired. Accordingly, the corresponding plots of typical dimensionless pressure curves are drawn. The influence of quadratic gradient term on non-Newtonian power law fluid and well test curves is analyzed to show that. The bottom hole pressure（BHP） is handly influenced by quadratic gradient term in wellbore storage period. However, in radial flow period, with the increase of dimensionless time, the influence degree of quadratic gradient term on BHP will increase. In long production time, the error of non-Newtonian power-law fluid which neglects quadratic gradient term is bigger than that of Newtonian power-law fluid. As power law index decreases, the error increases. The result is beneficial to improve the understanding of non-Newtonian power-law fluid percolation law.

关 键 词：非牛顿 幂律流体 二次梯度 数学模型 

分 类 号：TE312[石油与天然气工程—油气田开发工程]