【作者】 李月丽；

【导师】 伊向艺；

【作者基本信息】 成都理工大学 ， 油气田开发工程， 2010， 硕士

【摘要】 我国目前已投入开发的低渗透油气藏储量占总动用储量的三分之一以上,这些油气田大多数处于低产低效状态,而未动用油气地质储量中低渗透储量所占的比例更大,酸压是该类油气藏投产、建产、增产乃至稳产的主要技术手段。靖边气田下古生界碳酸盐岩储层具有低渗、低压、非均质性强的特点,储层改造难度较大,尤其是2000年大规模开发以来,常规酸化、酸压工艺都难以满足气田进一步勘探和经济高效开发的需要,因此2000-2003年开展了以提高单井产量为目的的变粘酸酸压工艺室内研究和现场试验。运用该工艺前期试验14口井,应用效果表明对于Ⅰ、Ⅱ类储层物性较好的井,变粘酸改造效果明显;对于物性差,但气源充足,区块储层连通性好的井,改造效果也较好;个别井由于现场配液不当,改造效果不好。后期推广应用9口井,保证配液质量和施工排量达到设计要求。通过对23口井的变粘酸现场试验效果分析,结果表明开发研制的变粘酸能较好地控制酸液滤失、延缓酸岩反应速度,实现了由常规稠化酸向变粘酸的转变,达到了预期试验效果,见效率达91.3%,平均无阻流量为39.7×104m3/d。本文运用灰色关联分析法研究了影响该地区酸压后产能的主控因素,研究表明施工排量、目的层电阻率、有效厚度、变粘酸酸液用量、孔隙度对该地区变粘酸压后产能的影响较大,结果可为该地区下一步选井选层和现场施工设计提供必要的指导。结合靖边气田的实际情况及所收集的现场实践资料提出了基于支持向量机的压后产能预测方法,通过对压后产能影响因素的排序分析,构建了靖边气田基于支持向量机的变粘酸压后产能预测模型,利用实际数据对此模型进行检验校正,预测结果表现出了良好的精度。利用经济净现值法分析评价了靖边气田23口变粘酸试验井的经济效益,通过计算投资回收期,内部收益率和财务净现值,结果表明采用变粘酸酸压工艺的经济效益相当明显。更多还原

【Abstract】 Currently, reserves of low-permeability gas and oil reservoirs which have being placed on production have made up more than one third of the total producing reserves of China. Most of these reservoirs are still in a state of low produce and low effect. Moreover, in unproduced reserves, reserves of low-permeability gas and oil reservoirs accounted for an even larger proportion. Therefore, acid fracturing techniques have become one of the main measures to make these low-permeability reservoirs put into production, increase production and even produce stably. The Lower Paleozoic carbonate reservoir of Jingbian Gas Field displayed the characteristics of lower permeability, lower pressure, higher heterogeneity and more difficult exploitation. It becomes difficult to satisfy the highly developing and economical requirement through conventional fracturing and acidizing methods after the wide development in the year of 2000, which consequently leads to the laboratory study and field testing of variable-viscosity acid targetted on improving the single well produivity in the year of 2000 to 2003. Based on the variable-viscosity acid fracturing technique, 14 wells had been constructed in the early stage, the result of which indicated that wells with a good physical property in the first and second type of reservoirs presented an obvious reconstruction effect; for wells with a bad physical property, if there was an enough gas sources and good connectivity, the effect was also relatively obvious. But, there were also some wells whose reconstruction effect was poor because of the improper acid compoundings. Hence, for the 9 wells tested in the later period, the liquid quality and construction displacement must meet the required design. According to the data & result analysis of the 23 wells’site testing, variable-viscosity acid showed a high quality of filtration control and reducing acid-rock reaction, which realized the initial goal, with the effective rate and the average open flow capacity reaching 91.3% and 39.7×104m3/d, respectively. In this paper, in order to analyse the main influencing factors and influencing degrees of all kinds of factors to deliverability after variable-viscosity acid fracturing, the grey correlation analytical method was applied, which showed that construction displacement, electrical resistivity, effective thickness, acid volume and porosity are the main influencing factors, which can provide an effective guidance for the later well and layer selection, fracturing design. Also in this paper, a production estimating model was established for variable-viscosity acid fracturing operation complying with the support vector machine(SVM). Verifying with prodution data, accurate performance on estimating was indicated by this model after proper organizing influence factors. Excellent ecnomical performance was demonstrated by computing the economic indexs such as payback period, internal rate of return and financial net present value.更多还原