苏北油田CO_(2)驱油同心双管分层注气技术

A Stratified Gas Injection Technique with Concentric Double Pipe for CO_(2) Flooding in Subei Oilfield

为了解决苏北油田CO_(2)驱油常规笼统注气工艺在实际应用中存在的吸气剖面不均匀、高渗层气窜严重和低渗层动用程度低等问题,在分析常规分层注气工艺特点的基础上,通过设计双级锚定式管柱、优选防腐蚀材质和质量流量计、改进分注器等井下工具,形成了CO_(2)驱油同心双管分层注气技术。根据现场实际情况,研究解决了管柱失稳、封隔器失效等问题,实现了准确分层注气。该技术在草舍油田C1井进行了现场试验,利用地面装置调节分层注入量,各项指标均满足分层配注要求,取得了良好的现场应用效果。试验结果表明,该技术具有操作简单、可靠性高和调配精度高等优点,可有效实现精细注气,为苏北油田CO_(2)驱油有效开发提供了新的技术手段。

Conventional gas injection techniques of CO_(2)flooding in Subei Oilfield face uneven suction profiles,serious gas channeling in high permeability layers,and low production degrees in low permeability layers in the techniques’application.In order to address these issues,we analyzed conventional stratified gas injection techniques and developed a stratified gas injection technique with concentric double pipe for CO_(2)flooding.It contains a two-stage anchored pipe string design,anti-corrosion materials and a mass flowmeter selection,with optimization of a gas injection separator and other downhole tools.According to the actual situation of field,the instability of the pipe string and the failure of the packer were solved,and an accurate stratified gas injection was accomplished.The technique has been tested in Well C1 of Caoshe Oilfield,and all indexes met the design requirements of stratified gas injection by adjusting the stratified gas injection volume with ground devices.The good test results showed that the technique has the advantages of convenient operation,high reliability,and high dispensing accuracy.Therefore,it can bring about fine gas injection and provide a new technical method for effective development of CO_(2)flooding in Subei Oilfield.