【作者】 杨立国；

【导师】 崔海清； 孙玉学；

【作者基本信息】 东北石油大学 ， 油气井工程， 2011， 博士

【摘要】 成膜钻井液具有半透膜的性能,能在井壁上形成一层隔离膜,在井壁的外围形成保护层,阻止钻井液滤液进入地层,从而有效地防止地层的水化膨胀,封堵地层裂隙,防止井壁坍塌,有效保护储层。本文从膜技术出发,研究了半透膜的固有性质,结合泥页岩的理化特性,研究泥页岩的成膜可能性,根据化学势平衡原理计算泥页岩的膜效率。在此基础上,系统地研究了活度、离子类型、阳离子交换容量、孔隙度、渗透率等因素对泥页岩膜效率的影响并进行了定性、定量的分析,最终提出了改善泥页岩膜效率的途径。本文建立了以泥页岩理化性能和组构特性为主的储层评价手段。采用X射线衍射分析、薄片分析、扫描电镜、CST测试等分析技术细致地研究伊通地区的储层理化性能并定性定量地分析了泥含量与定向度的关系,找出了导致该地区储层不稳定的因素。通过对吉林油田伊通地区储层进行岩芯浸泡实验、阳离子交换容量测定、ζ电位测定、膨胀率实验、滚动回收率实验、地层水活度测定等室内实验,综合分析实验结果可知,大部分评价指标均不高,处在弱到中等程度,故伊通地区的泥页岩属中等程度膨胀和中等程度分散。本文按照标准测试程序,对成膜钻井液体系的性能进行了一系列的测试。形成了以膜效率为主要评价指标、以井壁稳定性、储层保护效果等指标为辅的评价体系。评价结果显示该体系膜效率高达82%,实现了泥页岩成膜的理想化转换。此外,该体系能够有效地抑制粘土的水化分散膨胀、抗盐抗污染能力强、体系可抗180℃高温,性能易于调配。所研制的成膜钻井液体系在吉林油田进行了现场试验。结果表明,试验井井径规则,井壁稳定,能够有效地保护油气层。更多还原

【Abstract】 Membrane drilling fluid with the property of semi-permeable membrane can form a layer of isolating membrane on the sidewall face, which performs as a kind of protective layer in the outer area of the sidewall to prevent the drilling fluid from filtrating into the formation. In this way, the membrane drilling fluid can effectively avoid the formation hydration expansion, borehole wall sloughing and seal off the formation fracture, which can finally protect the reservoir.In this paper, properties of semipermeable membrane and possibility of membrane forming were studied both based on membrane technology and physicochemical properties of shale. Membrane efficiency was calculated according to the equilibrium principle of chemical potential. After that, influence factors related to membrane efficiency of shale such as activity, ionic types, CEC, porosity and permeability were analysed qualitatively and quantificationally. Finally, an approach of improving membrane efficiency of shale was concluded. This paper established a method of reservoir evaluation which mainly contains physicochemical properties of shale and petrofabric. With X-ray diffraction analysis, thin-section analysis, SEM and CST testing, physicochemical properties of Yitong area in Jilin Oilfield were carefully researched, and the relation between degree of orientation and shale content was analyzed. The factors that lead to wellbore unstable in this area were found. A lot of lab experiments were conducted to illustrate the properties of core in Yitong area, such as:Core soak experiment, CEC testing, Zeta potential test, swelling test, cuttings roller recovery test and formation water activity degree test, of which results showed that the most evaluating indicators are at a small to medium degree, therefore the dilatability and dispersity of shale in Yitong area is medium.A series of drilling fluid tests have been made according to standard test program. A drilling fluid evaluation system including some evaluating indicators was formed, of which the membrane efficiency is primary, wellbore stability and reservoir protection is as a supplement. The synthetic evaluation indicates that membrane efficiency is up to 82%, which idealizes shale membrane. Furthermore, this drilling fluid system restrains clay hydration effectively, it has a high salt resistance and strong anti-contamination ability, reachs a high temperature resistance of 180℃and its properties is easy to adjust as well. Some test wells in Jilin Oilfield were directed by membrane drilling fluid. It made the drilling succeed, kept the borehole gauge regular and consistent, stabilized wellbore, and protected the reservoir efficiently.更多还原