注烃混相驱提高石油采收率机理及其在葡北油田应用研究

【作者】 谭光天；

【导师】 杜志敏； 李国成；

【作者基本信息】 西南石油学院 ， 油气田开发工程， 2005， 博士

【摘要】 混相驱技术是提高原油采收率的一种非常重要的方法。在国外,由于混相驱技术比较成熟,随着对混相驱技术研究的重视及深入,取得了很大的成就。在国内,由于混相驱技术起步较晚,只在大庆、胜利、中原等油田进行过先导性试验,投入矿场实用的只有吐哈葡北油田的烃类混相驱及气水交替注入。 为了改善葡北油田注烃混相驱开发效果,本文开展了混相驱提高石油采收率机理及影响因素研究,系统总结了确定混相驱最小混相压力的方法,在数值模拟理论及应用研究基础上,开展了葡北油田混相驱开发效果跟踪模拟研究,为下一步的开发提供决策依据。 通过本文研究,取得的主要成果和认识如下: (1)系统研究了混相驱提高石油采收率的机理,注气过程中的相态变化特征,一次接触混相驱、多级接触混相驱、近混相驱的混相机理,混相驱影响因素以及改善混相驱开发效果的方法。 (2)系统研究了确定最小混相压力的实验室测定方法、经验公式和图版计算法、多级接触计算法、状态方程计算法、系线分析法、数值模拟法,并结合葡北油田的实际情况综合确定最小混相压力为33MPa。 (3)通过长岩心驱替实验和数值模拟研究,对葡北油田在注水、水气交替、气水交替、注气驱替方式下的开发效果进行了对比研究。从驱油效果来看,水驱效果最差,注气混相驱效果最好,气水交替混相驱油效果好于水气交替混相驱油效果。 (4)根据剖面模型研究,确定①气水交替混相驱过程中水气比1:2比水气比1:1和2:1驱油效果好;②注入段塞越小,驱替效率越高;③非混相驱替比混相驱油驱替效率低得多,突破时间也相对提前;④在气水交替混相驱过程中存在着较为明显的重力分异作用。 (5)葡北油田整体数值模拟结果显示:①随着开发的进行,位于西部高点的采油井,其油气比会普遍快速上升;但位于北东翼低点的采油井,其油气比上升速度较慢或保持初期水平;②停止注气,所有注气井转为注水井的开发效果明显变差;③新增两口开发井对整体开发效果的提高并不十分明显。 (6)生产动态分析显示,葡北油田东、西块间能量保持不平衡;高速开采是造成大部分单井见水及见水井含水上升速度加快的主要原因,稳油控水将成为葡北油田开发工作中最重要的环节。更多还原

【Abstract】 Miscible displacement is a very important technology of EOR. In abroad, Miscible displacement technology has been advanced for being attached importance to it and applied it. Due to the research of internal miscible displacement technology be too late, there have been only few pilot tests in DaQing, ShengLi, ZhongYuan oil field etc, and the practical oil-field application is only hydrocarbon miscible flooding and WAG in PuBei oil field of TuHa.In order to improve the development effect of hydrocarbon miscible flooding in PuBei oil field, in the paper, has studied the theory of enhancement oil recovery of hydrocarbon miscible flooding and affected factors, summarized the method to calculation MMP. Based on research results of numerical reservoir simulation theory and application, has been made a study, which trace simulated for the effect of hydrocarbon miscible flooding development in PuBei oil field. This provides the foundation for development next step.By the studies in the paper, could make some conclusions:Has studied the theory of enhancement oil recovery of hydrocarbon miscible flooding, the phase characters changes in the injection gas process, the theory of FCM, multi-contact miscible flooding, pseudo- miscible flooding, the effect factors of miscible flooding, and methods of the improvement effect of miscible flooding.Has studied the measure method of MMP in the lab, the experiential calculation method of it, the chart calculation method, multi-contact calculation method, the EOR calculation method, serial line analysis method, numerical simulation method, and has obtained the MMP of PuBei oil field by these methods.By long core displacement experiment and numerical simulation, has made comparative analysis of development effect for injection water, WAG, GAW, and injection gas in PuBei oil field. The effect of water flooding is the worst, but injection gas miscible flooding is the best, and GAW more than WAG, depends on effect of displacing oil,By studied section model, (1)in WAG and miscible flood process the water-gas ratio is 1:2, which have better displacement characteristics than the water-gas ratio is 1:1 and 2:1; (2) infuse lug more smaller, displacement more efficiency; (3)immiscible displacement has more smaller displacement efficiency than miscible displacement and the breakthrough time is brought forward too (4)the gravitational differentiation is obvious presented in WAG and miscible process.The numerical simulation results of whole PuBei oil field indicate: (1)with the exploitation, the oil-gas ratio in the oil wells which located in west high spot always quick climbed; but the oil-gas ratio in the oil wells which located in east low spot raised slowy or kept primary level; (2)stopping gas injection, and let all of gas input well tum to waterinjection well, the exploit effect will distinctness variation; (3)added two new development well have little effect to whole exploitation.(6) It shows energy has been kept a balance between east zone and west zone in PuPei to the production analysis. The main reason that the mainly wells have produced water and the water cut has raised up quickly is production beyond common scale. Therefore, it would be the most important schedule in the PuBei oil field development to produce oil steadily and decline water cut.更多还原