Most of gas wells in East China Sea produce water and are prone to liquid loading,leading to the reduced production or even halted production.It is necessary to implement water drainage and gas production measures to increase recovery.As an effective production technology,velocity string technology has been widely used in onshore gas fields,which is however limited by the large error of the conventional method and the high safety management requirements of the downhole safety valve,and thus has not yet been applied in China offshore gas field.Through selection of directional wellbore liquid carrying model,wellbore pressure drop analysis and production forecasting,a method for velocity string diameter optimization is established.The two-stage hanging method and supporting tools are applied to allow coiled tubing velocity string hanging while ensuring the proper functioning of downhole safety valve.An innovative snubbing operation method has been applied to avoid formation damage during kill well.The technology has been successfully implemented in the gas well A in the East China Sea with significant effect of water drainage and gas production.%东海气井普遍产水,易发生井筒积液,导致气井产量降低甚至停产,需要实施排水采气措施以提高采收率.速度管柱技术作为一种有效的排采工艺,已在陆地气田广泛应用.但受限于常规方法误差大和井下安全阀安全管理要求高等,其在国内海上气田尚未得到应用.通过优选定向井井筒携液计算模型、井筒压降分析及产量预测,建立了速度管柱管径优选方法;应用2级悬挂方法及配套工具,在保证井下安全阀正常工作的同时,实现连续管速度管柱全井筒悬挂;创新性实践不压井作业方法,有效避免了压井储层伤害.该工艺已在东海A气井成功实施,排采增产效果显著.
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