复合溶剂-过热蒸汽联动开采机理及表征

By combined injecting heavy oil-extract compounded solvent and super-heated steam, the heat consumption and the costing can be reduced simultaneously. Nevertheless, the coupling mechanism of heavy oil-extract compounded solvent and super-heated steam injection in the heavy oil is still unclear. In this project, the dynamic phase state and asphaltene precipitation elimination characteristics will be defined by using PVT test and High Temperature High Pressure Reactor experiment respectively; Based on dynamic phase state and thermodynamic theory, the reaction parameters of asphaltene will be determined; Finally, based on micro-physical modeling and one-dimension physical modeling, the characteristics of residual oil saturation reduction and permeability improvement will be confirmed, the mathematical flowing model of heavy oil-extract compounded solvent and super-heated steam injection will be built and solved, evaluation methodology of production effect of ganged injecting heavy oil-extract compounded solvent and super-heated steam will be then established. The research achievement is of significance to the development of solvent/steam/heavy oil physico-chemical reaction theory, besides the heavy oil efficient development theory can be established.

基于现场产出稠油所抽提的复合溶剂和过热蒸汽联动注入，可以在降低成本的同时进一步提高地层热利用率，从而实现高效开采稠油油藏，但目前复合溶剂与过热蒸汽在稠油油藏中的耦合作用机制尚不明确。本项目拟采用动态PVT测试和高温高压热动力学反应实验，揭示复合溶剂与稠油的动态相态特征以及复合溶剂与过热蒸汽耦合作用下沥青质沉淀生成和消除机制；基于动态相态特征和过热蒸汽与稠油/沥青质的热动力学反应理论，建立复合溶剂-过热蒸汽联动方式下稠油/沥青质的热动力学参数间定量关系；最后，通过稠油热采的微观和一维物理模拟，明确复合溶剂和过热蒸汽耦合作用下储层残余油饱和度降低和渗透率改善特征，构建复合溶剂-过热蒸汽联动开采机理的流动数学模型，寻求模型的数值解法，形成复合溶剂-过热蒸汽联动开采稠油的效果评价方法。本项目研究成果对发展和完善稠油热采物理化学渗流理论具有重要意义，也为稠油油藏高效开发提供坚实的理论基础。

复合溶剂和过热蒸汽联动注入可以高效开采稠油油藏，但复合溶剂与过热蒸汽在稠油油藏中的耦合作用机制尚不明确。本项目针对复合溶剂与过热蒸汽在稠油油藏中的耦合作用机制，首先进行了动态PVT测试和高温高压热动力学反应实验研究，揭示了复合溶剂与稠油的动态相态特征，获得了正丁烷、正己烷、正辛烷等溶剂在不同测试条件下的相平衡常数，为复合溶剂-过热蒸汽联动开采机理的流动数学模型建立奠定了基础。其次，通过稠油热采的二维平面物理模拟，揭示了复合溶剂和过热蒸汽耦合作用下储层残余油饱和度降低和温度场改善特征，明确了复合溶剂-过热蒸汽对稠油的耦合作用机理。再次，基于复合溶剂与稠油的动态相态特征和溶剂-过热蒸汽热力学状态方程，建立了复合溶剂-过热蒸汽联动开采机理的流动数学模型，形成了表征复合溶剂-过热蒸汽波及范围内传质传热过程的计算方法，并基于表征方法分析了该过程对溶剂滞留和顶层热损失的影响。最后，基于复合溶剂-过热蒸汽联动开采机理的流动数学模型和数值模型，形成了复合溶剂-过热蒸汽联动开采稠油的效果评价方法。本项目研究成果为稠油油藏复合溶剂-过热蒸汽联动开发提供理论基础，对发展和完善稠油热采物理化学渗流理论也具有重要意义。