作　　者： ; ; ; ; ;

机构地区： 中国石油天然气集团公司

出　　处： 《天然气工业》 2012年第4期69-71,125,共3页

摘　　要： 在对压力系数低、易漏地层,特别是裂缝型地层的固井作业中,采用常规密度的水泥浆进行固井极易引起井漏,造成固井失败或质量不合格。为此,根据准噶尔盆地西部隆起克百断裂带百口泉鼻隆构造上的百泉1井钻井复杂情况和地层情况,采用了2种超低密度水泥浆柱结构,以确保固井时上部防漏下部压稳,该井固井过程中无漏失,测井结果表明,低密度水泥浆固井质量合格。结论认为:①在压力系数低和有易漏地层存在的情况下,从固井设计到施工都应采用以"高效顶替、整体压力平衡"为核心的平衡压力固井工艺技术,控制环空形成的动液柱压力约大于地层压力和小于地层破裂压力;②正确选用和合理搭配固井施工压力、水泥浆密度和施工排量这3个参数,分析前期技术难点并制订合理的应对措施是保证固井成功的关键;③由于采用了超低密度水泥浆,降低了环空液柱压力与地层压力之间的正压差,减小了水泥浆的失水量,有利于保护油气层。 For the formations with low pressure coefficient and easy lost circulations,and especially for fractured formations,the conventional density slurry will usually lead to lost circulations,resulting in cementing failure or poor cementing quality.Through the study on the downhole drilling events and formation conditions in Well Baiquan 1 on the Baikouquan structure located at uplifted Kebai fracture belt in the west Junggar Basin,two cement slurry systems with ultra-low density are proposed and applied,to ensure no lost circulation in upper cementing and low kicks from the lower cementing.The final logging data shows that the cementing quality is good.The following conclusions are drawn.(1) For low-pressure thief zones,a balanced cementing technology,which has the core principle of high-efficiency displacement and overall pressure balance,can be applied during the cementing planning and operation to keep the dynamic hydraulic pressure in the annulus slightly above formation pressure and below the formation breakdown pressure.(2) Proper combination of operating pressure,slurry density and pump rate,and correct pre-job analysis and planning of countermeasures are critical for the success in cementing operation.(3) The application of ultra-low-density slurry will lower the positive pressure differential between the annulus hydraulic pressure and the formation pressure,reduce the water loss of the cement slurry,and be helpful for reservoir protection.

关 键 词： 准噶尔盆地 百口泉地区 固井 超低密度 水泥浆 技术措施 固井质量

领　　域： [石油与天然气工程]