摘要
大牛地气田产出液矿化度、硬度、钙镁离子、硫酸盐含量及悬浮物含量的增加均导致气井结垢机率明显增大。针对大牛地气田气井结垢问题,开展了气井结垢机理及防除垢技术研究。从微观机理上,成垢离子浓度(Ca^2+、HCO3-)的增加对气井结垢起决定性作用,且随着开采年限的增加,地层压力逐步降低,导致结垢加剧,pH值、矿化度对结垢影响相对较小。根据压力、流速、流态变化推测,喇叭口附近、近井产层以及炮眼处最易结垢。化学除垢主要是将配制的酸液通过泵注装置加注到井内,使其与管柱、射孔段或近井地带垢质发生反应。连续油管除垢则是将除垢工具连接在连续油管管柱上,其中,水力喷射除垢是将沿除垢工具的径向布置一系列直径2mm的喷嘴,液体射流产生的反作用力带动喷头旋转冲击、除垢;机械除垢是采用不同外径的三翼合金除垢磨鞋除垢。结合大牛地气田前期除垢试验,三种除垢均取得效果,化学除垢较其他两种除垢方式具有明显优势,成功率高,适应性更广,增产显著,不仅能解决井筒结垢问题,还能解决近井产层、炮眼结垢问题,建议优先采用化学除垢技术。
The increase of salinity,hardness,calcium and magnesium ions,sulfate content and suspended matter content of produced fluid in Daniudi Gas Field all lead to the increase of scaling probability.Aiming at the gas well scaling in Daniudi Gas Field,the scaling mechanism and descaling technology of gas wellsare studied.From the micro-mechanism,the increase of Ca^2+and HCO3-plays a decisive role on scaling of gas wells,the formation pressure gradually decreases,which leads to more scaling and relatively little effect of p H value and salinity on the scaling with the increase of production time.According to the change of pressure,flow rate and flow pattern,the formation near the bell mouth,near the well and at the borehole are easy to scale.Chemical descaling is mainly to inject the prepared acid into the well through the pump injection de-vice,so that it reacts with the scale at the string,perforation section or near wellbore.Coiled tubing descaling is to connect the descaling tool to the coiled tubing string,among them,hydraulic jet descaling is to arrange a series of nozzles with a diameter of 2 mm along the radial direction of the descaling tool,and the reaction produced by the liquid jet drives the nozzle for rotary percussion and descaling.The mechanical scale removal is to use three wing alloy wear shoes with different outer diameter to remove scale.Combined with the pre-liminary descaling test in the Daniudi Gas Field,three descaling methods are effective,the chemical descaling has obvious advantages over the other two methods with high success rate,wider adaptability and significant production increase,which can not only solve the problem of wellbore scaling,but also solve the problem of that of the pays near wellbore and at perforation.It is suggested that the chemical descaling is prior to use.
作者
赵建军
Zhao Jianjun(No.1 Gas Production Plant,SINOPEC Huabei Company,Zhengzhou Henan 450006)
出处
《中外能源》
CAS
2020年第8期61-68,共8页
Sino-Global Energy
关键词
大牛地气田
产出液特征
气井结垢机理
防除垢工艺
Daniudi Gas Field
characteristics of produced liquid
scaling mechanism of gas wells
descaling technology
