产液水平气井井下节流工艺参数优化及应用  

Optimization of Downhole Throttling Parameters of Liquid-producing Horizontal Gas Well

作　　者：周舰 Zhou Jian(Petroleum Engineering Technology Research Institute,Sinopec North China Petroleum Bureau)

机构地区：[1]中石化华北油气分公司石油工程技术研究院

出　　处：《石油机械》2018年第4期69-75,共7页China Petroleum Machinery

基　　金：国家科技重大专项"低丰度致密低渗油气藏开发关键技术"(2016ZX05048)

摘　　要：东胜气田现用井下节流工艺参数设计方法仅适用于气体计算,没有考虑含水对节流压差的影响,导致产液水平井采用井下节流工艺后节流器气嘴直径设计出现较大偏差,影响了产液水平井的连续稳定生产。鉴于此,通过引入滑脱因子K表征气液两相间滑脱效应,优化了气液两相嘴流压降模型,建立了产液水平井井下节流工艺参数优化方法。评价表明,新方法预测节流器入口压力与实测值非常接近,误差为6.23%,满足工程设计精度要求。现场应用结果表明:对于单井产液量低于5 m^3/d的水平井,井口压力控制在3 MPa左右,优化节流器嘴径和下深后,气井在井下节流+增压外输条件下防堵和排液效果明显改善,有效降低了气井临界携液流量,提高了气体举液能力,生产时率达99.2%,实现了产液水平井不注醇清洁开发。研究结果可为产液水平井井下节流工艺的现场应用提供参考。The downhole throttling parameter design method currently used in Dongsheng Gas Field is only suitable for gas well without considering the influence of water on the throttling pressure difference,resulting in dissatisfactory design of the nozzle diameter of the throtde in the application of downhole throttling process in the liquid producing horizontal well,which hinders the continuous and stable production of liquid producing wells.By introducing the slip factor K to characterize the slippage effect between gas-liquid phases,optimizing the pressure drop model of the gas-liquid two-phase nozzle flow,an optimization method for downhole throttling parameters of horizontal liquid producing wells is established.The evaluation shows that the predicted inlet pressure of throttle by the new method is consistent with the measured value with the error of 6.23%,which meets the engineering design accuracy requirements.Field application shows that,for a horizontal well with liquid production of less than 5 m3/d,given the wellhead pressure controlled at about 3 MPa,and with the optimization of the nozzle diameter and setting depth,the gas well anti-plugging and draining effects have been significantly improved under the condition of downhole throttling and pressurized transmission.The optimization method has effectively reduced the critical liquid carrying capacity of gas well,improved the gas lifting capacity,resulting increased production time rate of 99.2%,allowing the green development of horizontal liquid producing wells without alcohol injection.

关 键 词：产液水平井 井下节流 参数优化 排水采气 临界携液流量 

分 类 号：TE377[石油与天然气工程—油气田开发工程]