含硫化氢储气库注采井环空带压分析与对策

Cause analysis and countermeasures of annular pressure in injection and production wells of Hydrogen Sulfide gas storage in North China

储气库注采井“大吞大吐”式高速双向注采运行模式和储气库应急调峰保供的客观属性,使得近年来储气库注采井环空带压井比例较高,对储气库高效运行和注采井井筒完整性带来了巨大风险挑战。通过对华北地区X含硫化氢储气库H2-4井环空带压分析,在深入剖析环空流体组分来源和原井筒固井质量分析基础上,运用分布式光纤监测漏点识别技术和声速法(回声波形)计算环空保护液液面深度相结合方法,开展储气库注采井环空带压机理研究,明确了不同环空位置带压主要原因及带压程度。通过分析H2-4井现状并进行深入入研究,提出平衡注采、加密动态监测、应急处置方案和择机更换完整井筒完井管柱的对策,实现控制和治理环空带压井,保障储气库全生命周期注采安全。

The high speed bidirectional injection-production operation mode of “big swallowing and big pumping” in injectionproduction Wells of gas storage and the objective attribute of emergency peak adjustment and supply guarantee of gas storage have resulted in a high well kill ratio in annulus of injection-production wells of gas storage in recent years, which has brought great risks and challenges to efficient operation of gas storage and wellbore integrity of injection-production wells. X containing hydrogen sulfide gas storage in north China by H2-4 wells annulus with pressure, analyzing the actual situation of the annulus fluid component source and deep insight into the wellbore, on the basis of cementing quality analysis using the method of distributed optical fiber monitoring funnelled identification technology and the speed of sound(echo waveform) computing annulus protection fluid method, the combination of liquid level depth for gas storage injection-production well annulus pressure mechanism research, The main reasons and the degree of pressure in different annulus positions are clarified. well H2-4 annulus packer at 2 805.6 ~ 2 806.5 m intermittent loss, large loss, is the source of annulus pressure. At the same time, the sound velocity method(echo waveform) calculated that the depth of the annulus protection in H2-4 well was 2 560.97 m, 244.63 m different from the packer setting position of 2 805.6 m, which also indicated that the sealing capacity of the packer decreased and the possibility of packer loss was high. The balanced injection-production, infusing dynamic monitoring, emergency treatment scheme and countermeasures of replacing complete wellbore completion string with selective machine are put forward to control and treat annulus kill and ensure injectionproduction safety in the whole life cycle of gas storage.