火烧油层工况下固井水泥材料及耐高温耐腐蚀性能研究

发布时间：2018-05-14 07:28

  本文选题：火烧油层技术 + 稠油油藏　； 参考：《西南石油大学》2017年硕士论文

【摘要】：采用火烧油层技术开采稠油油藏过程中,固井水泥环需要长期在高温和CO2腐蚀环境下服役,由此造成的水泥环层间封隔失效、套损等难题已成为影响稠油热采井效益的主要原因之一。因此,为提高固井水泥石的耐久性和完整性,确保固井质量及油井安全寿命,论文研究了火烧油层工况下固井水泥材料及其耐高温耐腐蚀性能。本文从材料科学角度出发,综合考虑稠油热采井火烧油层工况,通过力学性能测试、渗透率和孔隙度测试、物相组成分析、微观形貌观察,考察了加砂油井水泥石的耐高温性能及失效演化规律;通过测试粒度分布、化学组成、矿物组成等水泥物化参数,结合高低温条件下水泥石的强度发展,考察了三种型号铝酸盐水泥基材的性能;通过测试水泥浆基本性能、稠化时间、早期强度、长期强度,优选与铝酸盐水泥伍配性好的外掺料和外加剂,对铝酸盐水泥浆体系进行改性研究;通过力学性能测试、渗透率和孔隙度测试、物相组成分析、微观形貌观察,初步探索了改性铝酸盐水泥石的性能变化规律及耐高温、耐CO2腐蚀机理。结果表明:火烧油层工况下高温环境导致的物相和微观形貌变化是加砂油井水泥石劣化失效的本质原因。高温300℃时,水化产物C-S-H凝胶和Ca(OH)2轻微脱水分解,加砂水泥石强度衰退、渗透率增加,水泥石处在劣化失效的临界点。高温400℃时,加砂水泥石轻微开裂膨胀,水化产物大量脱水分解,水泥石劣化失效加剧,已经不能满足对固井水泥石完整性的要求。另一方面,改性铝酸盐水泥浆基本性能良好,稠化时间可控、可调。硬化水泥石的早期强度较高,长期强度稳定发展,渗透率和孔隙度较低,其耐高温性能明显优于加砂油井水泥石。低温50℃环境下,掺入矿渣使得铝酸盐水泥石生成六方板状水化产物C2ASH8,弥补了晶型转变造成的微裂纹和孔隙,改善了铝酸盐水泥石强度发展的温度敏感性。高温500℃时,改性铝酸盐水泥石内部重结晶反应生成C12A7,有助于水泥石抗压强度保持稳定,水泥石表现出极强的弹性变形能力。此外,改性铝酸盐水泥石展现出较强的抗CO2腐蚀能力。低温水溶性CO2腐蚀环境下,腐蚀时间由7d延长至28d,改性水泥石的抗压强度不降反增,腐蚀层中只发现少量腐蚀产物CaCO3和CaAl2(CO3)2(OH)4·3H2O。而高温气态CO2环境对改性水泥石的腐蚀作用微乎其微,可忽略不计,试样腐蚀内外层未发现具有腐蚀性特征的微观区域及碳化产物。使用改性铝酸盐水泥浆体系进行了 2口井的现场试验,其中,D-1井和J-1井固井质量都较好,具有较好的应用前景。
[Abstract]:In the process of exploiting heavy oil reservoir with burning oil layer technology, cementing cement ring needs to be in service under high temperature and CO2 corrosion environment for a long time, which results in the failure of sealing between cement rings. Casing loss and other difficult problems have become one of the main reasons that affect the efficiency of heavy oil thermal recovery wells. Therefore, in order to improve the durability and integrity of cemented cement stone and ensure the cementing quality and safety life of oil well, the cementing cement material and its high temperature and corrosion resistance under the condition of burning oil layer are studied in this paper. In this paper, from the point of view of material science, the working conditions of heavy oil thermal recovery well fire are considered synthetically. Through the testing of mechanical properties, permeability and porosity, phase composition analysis and microscopic morphology observation, The properties of high temperature resistance and failure evolution of cemented stone in sanding well were investigated, and the strength development of cement stone under high and low temperature was studied by testing the physical and chemical parameters of cement such as particle size distribution, chemical composition, mineral composition, etc. The properties of three kinds of aluminate cement substrates were investigated, and the basic properties of cement slurry, thickening time, early strength, long-term strength, excellent selection of admixtures and admixtures with good compatibility with aluminate cement were tested. The modification of aluminate cement paste system was studied, and the performance change and high temperature resistance of modified aluminate cement paste were preliminarily explored by means of mechanical property test, permeability and porosity test, phase composition analysis and microscopic morphology observation. CO2 corrosion resistance mechanism. The results show that the change of phase and micromorphology caused by high temperature environment is the essential reason for the deterioration and failure of cemented stone in sanded oil wells. At high temperature of 300 鈩，

本文编号：1886938