【作者】 时宇；

【导师】 黄延章； 杨正明；

【作者基本信息】 中国科学院研究生院（渗流流体力学研究所） ， 流体力学， 2008， 博士

【摘要】 本文以海-塔盆地四类低渗透储层为研究对象,结合物理模拟、渗流力学、数值分析等方法,对比了低渗透砂岩、低渗透凝灰质砂岩及低渗透砂砾岩等不同岩性低渗透储层孔隙结构特征,并在此基础上对低渗透油藏单相和两相流体渗流规律进行了系统研究。研究结果表明1.低渗透砂岩、低渗透凝灰质砂岩储层在孔隙结构类型、喉道与渗透率关系、分选性与渗透率关系等方面较为接近,而与低渗透砂砾岩相差较大。海塔盆地储层可动流体百分数、平均喉道半径等在大庆外围低渗透油田中处于中等偏上水平。表明其开发效果将优于其余外围低渗透油藏。其中塔木察格砂岩的常规压汞、恒速压汞以及核磁共振数据表明该储层好于其它海塔低渗透储层。2.建立了新的变形介质油藏非线性渗流产能方程,结果表明储层非线性渗流的程度越大,介质的形变程度越大,油井的产能越低;在变形介质条件下增大生产压差,油井产能增加。但渗透率的降低幅度也增大,采油指数随生产压差的变化曲线上存在一个最大值,这为低渗透油藏产能优化提供了理论参考。3.建立了新的描述低渗透油藏非线性渗流机理模型。结果表明流度与启动压力梯度是形成非线性渗流的主要因素。并确定了产生非线性渗流的压力梯度区域。定量的研究了启动压力梯度、流度及微观孔隙结构对非线性渗流作用的影响。4.提出了不同低渗透储层可动油和残余油在地层孔喉中的分布规律。各储层残余油分布在大于储层流动孔喉下限半径的孔喉空间中,而不仅局限于小喉道。不同储层渗吸采油的比例不同,应据此制定合适的注水速度。5.建立了考虑低渗透渗流影响的油水相渗理论新模型。分析了非线性作用对油水相渗的影响。结果表明在非线性渗流区域范围内,压力梯度越高油相相渗越高,水相相渗越低。6.提出了新的油水两相驱替模型。研究了油水活塞式、非活塞式水驱油非线性渗流规律。与Darcy渗流相比,非线性渗流条件下油井所需生产压差更大,含水率更高,采出程度更低。更多还原

【Abstract】 Combining with the physical simulation, mechanics of fluid flow in porous medium and numerical analysis, the paper studied the pore structure characteristics of low permeability sandstone, low permeability tuffaceous sandstone and low permeability glutenite. Then, based on the above research, the seepage flow law of the single phase fluid and two phase fluids seepage were studied.1. Compared with low permeability glutenite, pore structure, relation of throat radius and permeability and separation of low permeability sandstone and low permeability tuffaceous sandstone is similar. Compared to other Daqing low permeability reservoirs, the movable fluid percent and average throat radius of Halar-tamuchage reservoir is in the mid to upper level. It showed that the development results will be better than other reservoirs. Meantime, the results of mercury injection, constant rate mercury injection and NMR presented that the tamuchage reservoir is better than other low permeability reservoir of Halar-tamuchage basin2. Non-linear seepage flow deliverability equation of deformation reservoir was established. The results presented that more serious non-linear seepage flow degree and bigger deformation resulted in lower deliverability. Increasing drawdown will decrease the non-linear effect impact on the seepage flow, and improve the deliverability. However, the decreased extent of the permeability will be enlarged. So, production index have a maximum with the drawdown on the condition of low permeability deformation reservoir. It afforded a reference for the deliverability optimization of low permeability reservoir.3. New model for describing the mechanism of non-linear seepage flow was presented. The results showed that mobility and start-up pressure gradient are the main reasons of non-linear seepage flow effect. Meantime, the pressure gradient region, which producing the non-linear seepage flow, was calculated. Impact of start-up pressure gradient, mobility and microscopic pore structure on seepage flow has been researched.4. The distribution character of movable oil and irreducible oil in low permeability reservoir was presented. The irreducible oil distributes not only in small pore-throat, but also in the pore throat that is bigger than the cut-off pore-throat. Proportion of imbibition produced oil to the overall produced oil is different in different low permeability reservoir of Hailar-tamuchage basin. So, the reasonable flooding rate can be obtained by the proportion.5. The oil/water relative permeability model with non-linear seepage flow was established. The non-linear seepage flow impact on the oil/water relative permeability was analysed. The result showed that bigger pressure gradient will result in higher oil relative permeability and lower water relative permeability.6. Displacement model of non-linear seepage flow was showed. Research on the piston like displacement and non-piston like displacement was presented. Compared with Darcy seepage flow, on the condition of non-linear seepage flow, the drawdown is higher; the water cut is bigger; degree of reserve recovery is lower.更多还原