近临界挥发性生屑云岩油藏生产特征与开发模式研究
发布时间：2018-10-21 16:55
【摘要】：近临界区定义为油藏温度Tr介于0.95～1.05倍流体体系临界温度Tc。B油藏属于近临界挥发性油藏,初期采用溶解气驱衰竭式开发取得了较好的效果,但因地层断裂和储层砂体尖灭等地质因素影响,各井控制区域间连通性差。目前,许多井区面临地层能量不足、地层能量差异大、产量衰减快等问题,油田生产形势严峻。此外,在油田实际生产过程中表现出"地层压力较低时生产气油比依然保持稳定"、"井筒中流体压力梯度倒置"等与常规溶解气驱衰竭式开发理论动态不一致、与井筒中流体重力分异相悖的异常生产特征。针对B油藏目前存在的生产问题及异常现象,本文通过流体PVT实验以落实油藏流体相态特征;根据油藏生屑云岩储层实际地质情况,剖析了油田生产动态异常特征产生的原因;结合国内外类似油田开发经验,根据不同驱替介质实验结果和数值模拟结果,确定了后期改善油田开发效果的调整措施。本文完成了以下主要研究工作并取得了相应的研究成果:(1)归纳总结了 B油田生屑云岩储层地质特征与油藏特征,归纳国内外类似挥发性油田开发技术对策以及油藏开发规律,为开展B油田后续相关研究工作奠定了基础。(2)完成流体常规PVT实验,落实了油藏近临界流体相态特征,明确了 B油田(Tc-T地=1℃)属于近临界高挥发性油藏。在压力高于25MPa时,油气体系属于界面张力低于1mN/m的低张力体系。(3)在对油田基本生产动态特征进行总结基础上,结合近临界流体特性及油藏生屑云岩储层孔喉结构特点,剖析了生产气油比异常稳定与井筒流体压力梯度倒置现象产生的原因和机理。(4)开展了不同介质(水、地层气、CO2或N2)驱替实验,并根据实验结果优选了油藏合理开发方式。(5)建立了挥发性油藏组分机理模型,论证了挥发性油藏不同开发方式(衰竭式、注水、注气)下的原油采收率,并对油藏转注时机进行了优化,得出注伴生气是最经济可行的开发方式,且注气时间越早,原油采收率越高。研究结果对油田后期开发调整有十分重要的指导意义。
[Abstract]:Near-critical zone is defined as reservoir temperature (Tr) of 0.95 ~ 1.05 times fluid system critical temperature Tc.B reservoir belongs to near-critical volatile reservoir. However, due to geological factors such as formation fault and reservoir sand body pinning, the connectivity between well control areas is poor. At present, many well areas are faced with problems such as insufficient formation energy, large difference of formation energy, fast production attenuation and so on. In addition, in the actual production process of oil field, "the ratio of producing gas to oil is still stable when the formation pressure is low", and the "inversion of fluid pressure gradient in wellbore" is inconsistent with the theory of conventional dissolved gas drive failure development. Abnormal production characteristics contrary to fluid gravity differentiation in wellbore. In view of the production problems and abnormal phenomena existing in reservoir B at present, this paper uses fluid PVT experiment to carry out reservoir fluid phase characteristics, analyzes the causes of abnormal characteristics of production performance in oil field according to the actual geological conditions of reservoir bioclastic dolomite reservoir. Combined with the development experience of similar oilfields at home and abroad, according to the experimental results of different displacement media and numerical simulation results, the adjustment measures to improve the oilfield development effect in the later stage are determined. This paper has completed the following main research work and obtained the corresponding research results: (1) summed up the geological characteristics and reservoir characteristics of bioclastic dolomite reservoirs in B oilfield, summarized the technical countermeasures and reservoir development laws of similar volatile oil fields at home and abroad. It lays a foundation for the subsequent research work in B oilfield. (2) the conventional PVT experiment of fluid is completed, the near critical fluid phase behavior of the reservoir is confirmed, and the near critical high volatility reservoir (Tc-T = 1 鈩，
本文编号：2285759
[Abstract]:Near-critical zone is defined as reservoir temperature (Tr) of 0.95 ~ 1.05 times fluid system critical temperature Tc.B reservoir belongs to near-critical volatile reservoir. However, due to geological factors such as formation fault and reservoir sand body pinning, the connectivity between well control areas is poor. At present, many well areas are faced with problems such as insufficient formation energy, large difference of formation energy, fast production attenuation and so on. In addition, in the actual production process of oil field, "the ratio of producing gas to oil is still stable when the formation pressure is low", and the "inversion of fluid pressure gradient in wellbore" is inconsistent with the theory of conventional dissolved gas drive failure development. Abnormal production characteristics contrary to fluid gravity differentiation in wellbore. In view of the production problems and abnormal phenomena existing in reservoir B at present, this paper uses fluid PVT experiment to carry out reservoir fluid phase characteristics, analyzes the causes of abnormal characteristics of production performance in oil field according to the actual geological conditions of reservoir bioclastic dolomite reservoir. Combined with the development experience of similar oilfields at home and abroad, according to the experimental results of different displacement media and numerical simulation results, the adjustment measures to improve the oilfield development effect in the later stage are determined. This paper has completed the following main research work and obtained the corresponding research results: (1) summed up the geological characteristics and reservoir characteristics of bioclastic dolomite reservoirs in B oilfield, summarized the technical countermeasures and reservoir development laws of similar volatile oil fields at home and abroad. It lays a foundation for the subsequent research work in B oilfield. (2) the conventional PVT experiment of fluid is completed, the near critical fluid phase behavior of the reservoir is confirmed, and the near critical high volatility reservoir (Tc-T = 1 鈩，
本文编号：2285759
本文链接：https://www.wllwen.com/kejilunwen/shiyounenyuanlunwen/2285759.html
