速度管排水采气井筒压降模型的评价及优选

School of Petroleum and Gas Engineering, Southwest Petroleum University, Chengdu 610500, China State key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China Research Institute of Engineering and Technology, Huabei Company, SINOPEC, Zhengzhou 450006, China)

准确计算速度管中气液两相流压力降，是速度管排水采气工艺优化设计、生产动态及排液效果分析的基础。文中以Orville Gaither 1963年以天然气/水作为实验流动介质，在管径25.4，31.75 mm速度管中测试的单相液流、气液两相流的实验数据为基础，首先优选了摩阻系数计算方法，其次对速度管中气液两相流的压降模型进行评价和优选， 最后利用大牛地3口水平井速度管流压测试数据进行了验证。利用单相液流测压数据进行摩阻系数优选表明，AGA方法计算结果与实际情况最吻合，误差最小（压降平均绝对误差为22.37%）；8个常用气液两相管流压降模型评价表明，Gray模型准确性最好，其次为Ansari模型。这为速度管排水采气井优选出了可靠的两相流压降计算模型，有助于提高工艺设计及排液效果诊断水平。

Accurately calculating the pressure drop of two-phase flow in velocity string is the basis of optimizing design for drainage and gas recovery and analyzing production performance and drainage effect. In this paper, experiment data are from Orville Gather (1963) who carried out a single-phase and two-phase experiment in 25.4 and 31.75 mm velocity strings using natural gas/water as experimental medium. Firstly, the calculation method of friction factor is optimized. Secondly, the pressure drop of two-phase flow is evaluated and optimized. Finally, the optimum pressure drop of two-phase flow is verified by production data of three typical horizontal wells in Daniudi Gas Field after installing velocity string. Using the measured pressure data of pure liquid flow to optimize friction coefficient shows that the calculation of AGA method is the most consistent with actual results, whose error is the least（the average absolute error of pressure drop is 22.37%）. The evaluation of eight frequently-used two-phase flow pressure models shows that the priority selection to calculating wellbore pressure drop is Gray model and the second is Ansari model. This study can optimize a dependable calculation model of two-phase flow pressure drop for drainage and gas recovery by velocity strings and help to improve the technology design and the diagnosis level of drainage effect.

10.6056/dkyqt201501029