【作者】 杨枝；

【导师】 王成彪； 孙金声；

【作者基本信息】 中国地质大学（北京） ， 钻井工程， 2010， 博士

【摘要】 碳酸盐岩是极为重要的储集岩,占世界沉积岩总面积的20%,其油气储量占世界总储量的50%。近几年我国先后在塔里木、四川等地区取得了碳酸盐岩油气资源的重大发现。碳酸盐岩油气藏具有埋藏深,天然裂缝发育,物性差,非均质性强等特点,储层极易受到污染损害,其储层漏失导致的损害更是难以估量,严重制约着上述地区裂缝性碳酸盐岩储层的勘探开发效果。为此,国家科技重大专项《大型油气田及煤层气开发》项目21-深井钻录、测试技术和配套装备中专题2“碳酸盐岩、火成岩及酸性气藏高效安全钻完井技术”将裂缝性碳酸盐岩的储层保护技术作为重点研究内容。本文以塔里木盆地塔中地区为研究对象,开展了该地区裂缝性碳酸盐岩储层保护技术研究。通过对塔中地区裂缝性碳酸盐岩储层岩石性质、敏感性矿物含量、储层物性、储层流体组成和储层敏感性研究,揭示了该储层主要损害机理。实验结果表明,引起该储层损害的主要因素是钻井液固相及液相对储层的侵入、极强的应力敏感性和水锁效应。针对裂缝性碳酸盐岩储层损害的特殊性,建立了裂缝性碳酸盐岩储层损害评价新方法。采用新型人工造缝的天然岩心和模拟裂缝岩心的钢板模具来评价钻井液体系对裂缝性碳酸盐岩储层的损害程度和高效封堵型钻井液对裂缝性储层的保护效果。并将稳定井壁的力学理论“应力笼”有限元物理模型引入裂缝性碳酸盐岩储层保护,分析了裂缝性储层的漏失机理,形成了裂缝性碳酸盐岩储层防漏堵漏技术方法,即通过架桥材料在诱导裂缝处的封堵可形成压力隔离,从而增大井壁圆周应力,提高地层承压能力,将钻井液的侵入控制在最低限度。基于裂缝性储层损害机理和“应力笼”防漏堵漏技术方法,对于低孔低渗微裂缝储层,优选并研制了高效封堵隔离膜剂、高效防水锁剂和特殊纤维封堵剂,形成了一套“双膜”协同保护裂缝性储层的钻井液技术;对于漏失性裂缝储层,优选了防漏失封堵颗粒材料,形成了一套防漏失“双膜”协同保护裂缝性储层的钻井液技术。室内评价和现场先导性试验表明,“双膜”体系可迅速形成致密保护屏障,阻止钻井液中固相和液相侵入储层,可有效地封堵大孔喉、不同裂缝宽度的油气层,储层保护效果显著,是一套适合塔里木盆地塔中地区保护油气藏的钻井液技术,推广应用前景广阔。同时可为国内及海外相关油气田海相裂缝性碳酸盐岩储层保护提供技术支撑。更多还原

【Abstract】 The carbonate reservoir is the important reservoir rock, which is 20% of the all sedimentary rock areas in the world and its hydrocarbon reserve volume is the 50% of the all reserve volume of the world. In recent years, the major carbonate oil and gas resources are found in Tarim, Sichuan of China. The carbonate reservoir have many characteristics, such as the more deep buried reservoir, the growing natural fracture, the bad trait and the strong nonuniformity. So the heterogeneous formation is easily damaged, and the damage are hard to ponderate by the lost circulation. The effect of exploratory development is constrainted seriously in these regions. Therefore, relying on the major projects of national science technology, it is urgently necessary to do research on the reservoir protection of fractured carbonate reservoir. In this paper, the fractured carbonate reservoir protection technology is studied in Tarim Basin.The rock properties, the sensitivity of mineral content, reservoir properties, reservoir fluid composition and reservoir sensitivity of the fractured carbonate reservoir were studied, the main damage mechanism of reservoir is revealed, that it show us the main factors which are the invasion into the fractures by drilling fluid, the stress-sensitive, and water-blocking.On account of the special damages of fractured carbonate reservoir, a new damage assessment method of fractured carbonate reservoir is established. Using the new artificial fractured cores and steel mold to evaluate the damage extent on fractured carbonate reservoirs of drilling fluid and the protective effect on fractured carbonate reservoirs of efficient plugging-off drilling fluid.The mechanical theory which is called "stress cage" is applied into the reservoir protection technology, the leakaged mechanism is analyzed, a fractured carbonate reservoir plugging technical method is established. The method is that to form the pressure isolation through the bridge material blocking the cracks, thereby increasing the well wall hoop stress, improving the system bearing capacity and optimizating distribution particle size of the drilling fluid.Based on the damage mechanism of fractured reservoir and plugging technical method, the film former, the anti-water-locking agent and the special fiber blocking agent are selected and invented, the drilling fluid technology of“double membrane”collaborative protection is formed, and it is suitable for the low porosity and low permeability fractured reservoirs. The drilling fluid technology of lost circulation prevention is formed by selecting the the sealing materials.Laboratory evaluation and field test show that the "double membrane" system can quickly form a dense protective barrier to prevent the invasion of solid phase and liquid by drilling fluid, which can block a large pore, different crack width of reservoir effectively. The protective effect of this technology are significant. It is a set of drilling fluid technology on protection of oil and gas reservoir in Tarim Basin. It can meet the requirements of reservoir protection during drilling operations, and provide technical support for marine fractured carbonate reservoir protection technology of home and abroad.更多还原