节点文献
机械式防砂管原油渗流试验及数值模拟
Experimental and Numerical Simulation Research on Crude Oil Seepage of Mechanical Sand Screen
【作者】 王静;
【导师】 闻建龙;
【作者基本信息】 江苏大学 , 流体力学, 2009, 硕士
【摘要】 机械式防砂是目前针对稠油疏松砂岩油藏采油工艺中广泛运用的防砂采油技术,但稠油疏松砂岩油藏的高粘性,低流动性,易吸附性等特点使防砂管极易发生堵塞,不能维持较长时间的防砂工作,给油藏的开发带来极大的困难。因此对机械式防砂管性能的改进是机械式防砂管采油要解决的重要问题,本文将地层多孔介质渗流理论和机械式防砂管采油技术联合进行研究,以设计新型适合稠油疏松砂岩油藏的防砂管和捡测新型防砂管性能为重点,开展了以下几方面的工作:1.以渗流力学、两相流体力学为基础,研究稠油疏松砂岩油藏地层原油渗流运动,从而推导含泥砂稠油流体在地层渗流运动的数学模型方程。2.以油气井出砂理论和防砂方法为基础,对现行防砂管在采油作业中的实际情况进行分析,归纳总结现行防砂管在防砂渗流作业中存在的问题。3.从改进防砂管结构和过滤材料两个方面拟定出新型防砂管的设计方案,并加工制作新型防砂管样品,进行防砂渗流试验研究。4.以还原油藏中真实情况为目标设计和搭建机械式防砂管原油渗流试验台,使渗流试验满足高温高压及地层出砂等地层中的原油渗流环境,并以此为基础进行原油渗流试验。5.通过防砂管基本性能试验、新型防砂管性能对比试验和压力极限状态下的堵塞试验得到:防砂管的渗透率受压差影响明显;含粘土等固体颗粒的原油在渗流过程中更容易使防砂管发生堵塞;在相同的渗流环境下经滤材改进设计的新型防砂管渗透率最高,阻力系数最小,渗流流量最大,并且渗透率随时间降幅最小,渗透性能最好;同时在极限压力状态下,相同的实验时间内,原防砂管已经堵塞,而经结构改进设计的新型防砂管渗流流量最大,能够维持长时间稳定渗流状态,试验结束后,绕丝完好,没有大量泥沙淤积吸附现象。6.采用CFD相关软件进行几种有代表性的数值模拟,即在防砂管未堵塞和堵塞两种情况下,对原油单相流体和含粘土颗粒的液固两相混合流体的渗流运动进行模拟计算,计算结果表明在地层原油渗流经过防砂管周围的多孔介质时,压力变化明显,流体流速缓慢,在原油中含粘土渗流的情况下上述情况更为明显。由此分析得到:适用于稠油疏松砂岩油藏的新型防砂管的进一步研制应着重考虑由于较大压力变化造成的防砂管结构形变,低流速摇曳力造成的矿物颗粒对渗流孔隙的堵塞等因素。
【Abstract】 Mechanical sand control is a widely used sand control technology for unconsolidated sandstone heavy oil reservoir, but the high viscosity, low liquidity, and so easy to adsorption characteristics for unconsolidated sandstone heavy oil reservoir make the mechanical sand screen can easily be blocked up, unable to maintain a longer working time for sand controlling, and create great difficulties for the reservoir development. Therefore, the important issues will be solved for mechanical sand control production is the improvement of mechanical properties of sand screen. This articlel combined study on Porous Media Formation Theory and the mechanical sand control techniques ,take designing a new type sand control screen for unconsolidated sandstone heavy oil reservoir and testing the new sand control screen performance as the focus, the following aspects:1. Based on seepage mechanics and two-phase fluid dynamics to study the crude oil seepage movement in unconsolidated sandstone heavy oil reservoir, conclude the mathematical model equations of the crude oil with sand seepage movement in unconsolidated sandstone heavy oil reservoir.2. Based on oil and gas wells in the sand theory and methods, analyze the actual situation on oil sand operations of the existing sand screen, and summarized problems of the existing sand screen in the sand control seepage.3. Make a designing method for new sand control screen from next aspect: improve the structure and filter material, then manufacture into new sand control sample, carried out experimental study of sand control seepage.4. Designning and building the crude oil seepage experimental setupt aim at restoring the real seepage situation in reservoir, such as the essential high temperature, high pressure and so on, and as a basis for the crude oil seepage experiment.5. Through the permeability comparative experimental and seepage experiment under pressure to limit state, showed that the differential pressure affected penetration rate significantly obviously; the mixed fluid with clay and other solid particles in the flow more easily formed the sand tube plug; in the same seepage environment, the new type of sand control had the highest penetration rate, the minimum drag coefficient, the largest seepage flux , the smallest penetration rate decline over time and the best permeability; under the same situation of pressure to limit state and time, old sand control have formed sand tube plug, but the new structure designed sand control have the lagest seepage flux, and be able to maintain a long steady-state flow condition, at the end of the experiment, the winding wire intact, without adsorption phenomena of a large number of sediment deposition.6. Adopted CFD software for several representative numerical simulation, that had formed tube plug and not, then establish the heavy oil wells seepage flow model in loose sandstone reservoir and the surrounding area for single-phase flow of crude oil and liquid-solid two-phase flow of mixed fluid with clay and other solid particles. The results show that show that crude oil flow through the porous media around the sand, pressure changed significantly, flow slowly, silt deposition seriously around tubular upper and lower ends, at the same time, all tose will be worse for the mixed fluid with clay and other solid particles. Those show that: the improvements of new sand screen should concentrate on the question of mineral particles on the pore blockage caused by the low seepage flow swaying force; a larger seepage pressure change and the sand screen structure deformation caused by the uneven distribution of sediment deposition, as well as the resulting effect of sand screen without ideal shorter working hours and so on.
【Key words】 seepage; sand control; mechanical sand screen; permeability; seepage resistance; porous media; numerical simulation;