全隐式化学驱油藏教值模拟研究

发布时间：2019-05-10 03:44

【摘要】：我国老油田普遍处于高含水开发阶段,平均含水已达到90%。化学驱技术是挖掘油田潜力,保证稳产的重要措施。目前,化学驱在国内主力油田已进入大规模工业化应用阶段。化学驱油藏流动机理十分复杂,伴随多种物理变化和化学反应。目前,了解化学驱主要物化机理,正确认识化学驱油藏开发规律,有效提高油藏采收率是石油开发领域研究的重点问题。国内外研究人员主要通过室内机理实验、数值模拟以及现场试验等手段来对影响化学驱开发效果的主要因素进行研究,掌握化学驱开发规律,指导化学驱现场实施。其中,化学驱数值模拟是联系室内机理实验和现场试验的纽带,也是化学驱项目可行性评价、方案优化和开发效果预测的重要工具,因而在化学驱研究领域受到广泛重视。本文围绕化学驱油藏数值模拟方法展开研究,在化学驱数学模型、计算方法等方面进行了研究和改进,并针对化学驱现场压力测试数据缺乏可靠分析手段的实际状况,开展了化学驱数值试井研究,提出了新的试井模型和参数解释方法,从而提高了聚-表二元驱试井解释的可靠性和现场压力测试数据的利用率,对准确评估油藏性质、掌握开发动态有着重要的意义。论文主要工作及创新如下:1.在考虑化学驱主要驱油机理和物化现象并合理简化的基础上建立了多相、多组分化学驱数学模型。基于PEBI网格采用有限体积离散建立了全隐式数值求解方法。使用C++语言自主研发了化学驱数值模拟软件。通过与UTCHEM对比验证了软件的正确性。2.应用变量替代算法处理表活剂驱相平衡计算问题。对各种相态变化情况推导不同的离散线性化方程组,并在求解时对饱和度和组分浓度进行替代处理,在不影响计算精度的前提下提高了计算速度。3.提出了聚驱渗透率下降新模型。利用已有实验研究结果,在聚驱数值模拟中引入聚合物浓度对相渗曲线影响的机理描述。该模型克服了现有DPR(disproportionate permeability reduction)模型的局限性。通过数值实验证明了考虑聚合物浓度对相渗曲线影响机理的必要性。在此基础上,提出了一种利用试井解释对注聚开发过程中由聚合物导致的地层固有渗透率损伤进行评估的方法。4.将自主研发的化学驱数值模拟软件应用于试井分析中。用数值试井方法研究了化学驱瞬态压力响应特征及相关因素的影响。着重研究了聚合物溶液非牛顿流变特性对瞬态压力响应的影响,发现剪切变稀会导致早期压力导数曲线出现明显的抖动。基于此提出一种利用试井分析获得地层中聚合物流变性的方法,并结合现场试验进行了验证。
[Abstract]:The old oil fields in China are generally in the stage of high water cut development, and the average water cut has reached 90%. Chemical flooding technology is an important measure to tap the potential of oil fields and ensure stable production. At present, chemical flooding in the main domestic oil fields has entered a large-scale industrial application stage. The flow mechanism of chemical flooding reservoir is very complex, accompanied by a variety of physical changes and chemical reactions. At present, understanding the main physical and chemical mechanism of chemical flooding, correctly understanding the development law of chemical flooding reservoir, and effectively improving reservoir recovery are the key problems in the field of petroleum development. Researchers at home and abroad mainly study the main factors that affect the development effect of chemical flooding by means of indoor mechanism experiment, numerical simulation and field test, master the law of chemical flooding development, and guide the field implementation of chemical flooding. Among them, the numerical simulation of chemical flooding is not only the link between laboratory mechanism experiment and field test, but also an important tool for feasibility evaluation, scheme optimization and development effect prediction of chemical flooding project, so it has been paid more and more attention in the field of chemical flooding research. In this paper, the numerical simulation method of chemical flooding reservoir is studied, and the mathematical model and calculation method of chemical flooding are studied and improved, and the actual situation that the field pressure test data of chemical flooding is lack of reliable analysis means is studied and improved. The numerical well test research of chemical displacement is carried out, and a new well test model and parameter interpretation method are put forward, which improves the reliability of cluster-table binary displacement well test interpretation and the utilization rate of field pressure test data, and accurately evaluates the reservoir properties. It is of great significance to master the development dynamics. The main work and innovations of the paper are as follows: 1. On the basis of considering the main flooding mechanism and physicochemical phenomena of chemical flooding and reasonably simplifying the mathematical model of multiphase and multicomponent chemical flooding is established. Based on PEBI grid, a fully implicit numerical method is established by finite volume discretization. The numerical simulation software of chemical flooding is developed by using C language. The correctness of the software is verified by comparison with UTCHEM. 2. The variable substitution algorithm is applied to calculate the phase equilibrium of surface active agent. Different discrete linear equations are derived for various phase state changes, and saturation and component concentration are replaced in the solution, which improves the calculation speed without affecting the calculation accuracy. A new model of polymer flooding permeability decline is proposed. Based on the existing experimental results, the mechanism description of the effect of polymer concentration on the phase permeability curve is introduced into the numerical simulation of polymer flooding. This model overcomes the limitation of the existing DPR (disproportionate permeability reduction) model. Numerical experiments show that it is necessary to consider the influence mechanism of polymer concentration on the phase infiltration curve. On this basis, a method for evaluating the formation natural permeability damage caused by polymer in the process of polymer injection development by well test interpretation is proposed. 4. The self-developed numerical simulation software of chemical drive is applied to well test analysis. The transient pressure response characteristics of chemical flooding and the influence of related factors are studied by numerical well test method. The effect of non-Newtonian Rheological properties of polymer solution on transient pressure response was studied. It was found that shear thinning would lead to obvious jitter of early pressure derivative curve. Based on this, a method of obtaining polymer logistics denaturation in formation by well test analysis is proposed and verified by field test.
【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TE357.46

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