零析水水泥浆配合双凝双压固井工艺在泽74-1X井固井作业中的应用

泽74－1X井是为评价泽74断块奥陶系潜山油气情况，在泽74－1井开窗侧钻的一口评价井，该井井斜变化大，井眼轨迹呈螺旋型，地层特性复杂。该井通过采用ZJ－2低失水、零析水水泥浆体系配合双凝双压固井工艺，固井施工顺利，全井主要封固段固井质量良好。现场应用表明，ZJ－2降失水水泥浆体系具有流动性好、水泥浆初始稠度低、析水为零等特点，稠化时间易于控制，十分适合大斜度井和井眼轨迹不佳的井的固井要求，能够很好地保护油气层；双凝双密度水泥浆体系应用于压力变化大的超长裸眼封固段固井，施工安全，固井质量好，只要水泥浆密度设计合理，工程上采取小排量替浆，可防止固井漏失，提高作业成功率。

Using cement slurry of zero water precipitation and two-stage setting and double densities for cementing in Well Ze74-lX

Well Ze74-lX is an evaluation well sidetracked in the original well of Ze74-1, for evaluating the oil and gas reserves in the buried hill of Ordovician system in block Ze74. The geological condition in Well Ze74 is very complex, while there are large-scale of deviation changes, and the hole profile is in spiral. By adopting cement slurry system ZJ-2 of low fluid loss and zero water precipitation, combining the use of cementing technique of two-stage setting and double killing, the cementing job is smoothly carried out with good cementing quality. Field using shows that the cement slurry system has such advantages as good flowability, low initial thickness and zero water precipitation, etc; its thickening time can be easily controlled, which is suitable for cementing the highly deviated hole and well with uncontrolled trajectory, and can meet the requirements of formation protection. When the two-stage setting and double-density cement slurry is used for isolating the ultra-long open hole with tremanderous pressure changes, smooth and safe cementing operation can be conducted with good cementing quality; by reasonably designing the cement slurry densities and adopting low flow rate for displacement, the problem of lost circulation can be effectively prevented.