摘要
理论研究与现场实践表明,注水泥顶替效率低主要是由套管偏心度过大、环空壁面上钻井液滞留层形成和注水泥顶替界面失稳造成的。针对上述三方面问题,调研了目前固井注水泥顶替机理的研究方法与成果,分析了研究中存在的不足,提出了注水泥顶替机理后续研究的相关目标:建立套管极限偏心度与井斜角、流体流变性能等参数的定量模型,进而指导下套管时扶正器安放设计(尤其是在大斜度井和水平井中);针对环空壁面上钻井液滞留层问题,理论分析其形成条件,确定无滞留层形成时流体性能参数之间满足的定量关系;为保证注水泥顶替界面的稳态,需研究适用于在不同井斜角的偏心环空中两相流体(非牛顿流体)之间顶替界面的理论模型,从而推导实现界面稳态的定量条件。通过对注水泥顶替机理开展系统的理论研究,可为提高顶替效果、改善固井质量提供一定的参考和依据。
Theoretical study and field practice show that low displacement efficiency results from high casing eccentricity, drilling mud stagnant forming on the annular wall or instable displacement interface. Aiming at these three problems, a lot of research methods and results were consulted, shortages were analyzed and research objectives following further study were given. The quantitative model, expressing the relationship between ultimate eccentricity and factors including deviation angle and fluid parameters, etc., needs to be built and then guides the centralizer design especially for highly-deviated or horizontal well.Considering the forming condition of drilling mud stagnant layer, determining the quantitative relationship to guarantee that no drilling mud stagnant layer exists on the wall is analyzed. To achieve a stable displacement interface, the mathematic model which can describe the displacement interface between non-newtonian fluids in the eccentric annulus suitable for wellbores with any deviated angle should be established; furthermore quantitative condition about stable displacement interface can be obtained. After the above systemic theoretical research, theoretical reference and basis for the displacement parameters adjustment to improve displacement efficiency will be got.
出处
《断块油气田》
CAS
北大核心
2016年第3期393-396,共4页
Fault-Block Oil & Gas Field
基金
中国石化石油工程技术服务有限公司"水平井细分压裂技术"项目子课题"鄂尔多斯油气田返排压裂液重复利用技术研究"(SG1312-05K)
关键词
固井
顶替效率
套管偏心
顶替界面稳定性
钻井液滞留层
cementing
displacement efficiency
casing eccentricity
displacement interface stability
drilling mud stagnant layer
