【作者】 孙茂盛；

【导师】 李兆敏；

【作者基本信息】 中国石油大学 ， 油气田开发工程， 2007， 博士

【摘要】 通过室内实验的方法,对油田常用的几种发泡剂进行了筛选,从发泡能力、抗盐性、抗油性和抗温性等几个方面综合评价,实验结果显示LJH-03发泡剂具有良好的性能,将5‰作为LJH-03发泡剂的最佳发泡浓度。并且通过实验的方法确定(0.4-0.6)%CMC-HV+(0.3-0.5)%PAM作为稳定剂体系。通过落球法测得了泡沫流体的静态粘度随泡沫质量的变化关系。论文以直井、斜井、水平井冲砂洗井的正循环方式为研究对象,利用FLUENT软件中的离散相模型对泡沫流体在油套环空中的携砂能力进行了数值模拟研究,得到了不同直径的砂粒在泡沫流体中的携砂率和停留时间随环空管道倾角和泡沫流体流速的变化关系,与相同条件下水的性能进行了比较,并进行了定性分析。从模拟结果可以看出泡沫流体具有良好的携砂能力,而且更适合于水平井的冲砂洗井。环空偏心使得泡沫流体的携砂率降低,而对接近水平段的影响尤为突出,对接近竖直段的影响较小。在现场泡沫流体冲砂作业中应尽量减小油管的偏心,保证较高的携砂率。根据质量守恒方程、动量守恒方程和能量守恒方程建立了泡沫流体冲砂洗井的数学模型,该模型可以用于冲砂洗井井口参数设计。编制了相应的计算程序,通过算例对井筒内泡沫流体循环过程进行了模拟,得到环空回压与井口注入压力、井底压力、井口注入气体流量、泡沫基液的流量之间的关系。从计算结果可以看出,环空回压对其它各参数的影响较大,现场应用时应注意对环空回压的控制。通过现场实验可以看出,该程序能够满足直井、斜井、水平井冲砂洗井的要求,泡沫冲砂有效防止了冲砂液漏失,能够顺利建立起油套循环,并且冲砂洗井后能够迅速恢复生产,产量还有一定的增加。泡沫流体冲砂洗井技术是清除低压油井井底出砂的一项有效措施。论文的结论对完善泡沫流体冲砂洗井理论,指导现场应用具有重要的意义。更多还原

【Abstract】 Through laboratory experiment, several kinds of foaming agents which are often usedin oil field are researched. The abilities of foaming, salt resistance, oil resistance, andtemperature resistanceof the agents were extimated. The result shows that LJH-03 hasgood performance, and the best concertation of LJH-03 is 0.8%. The composition ofstabilizer system is (0.4-0.6)%CMC-HV+(0.3-0.5)%PAM. Rheology and static viscosityof foam fluid were gained.Sand-flushing of direct well, inclined well and horizontal well was resezrched.Discrete phase mode in FLUENT was used to simulate sand carrying capability of foamfluid, and relations of sand carrying rate and residence time in foam fluid to inclinationangle of annular pipe and fluid velocity were researched. The simulation results of foamfluid were compared with that of water on the same condition, and qualitative analyseswere provided. It can be seen that sanding carrying capability of foam fluid is muchbetter, and it is especially suitable for sand-flushing of horizontal well. Sand carrying rateis increased with the increase of foam fluid velocity, and it is decreased because of annular spaceeccentricity. The impact of annular space eccentricity on horizontal segment is fiercer than that onvertical segment of oil well.Based on mass and momentum conservation equations, mathematical model forsand-flushing of direct well, inclined well and horizontal well was established, whichcan be used for sand-flushing parameter design. Corresponding computer program wasdesigned, and foam fluid cyclic process in wellbore was simulated. Through thecalculated example, the relations of annular back-pressure to injection pressure,bottom-hole pressure, volume flux of injection gas under stander condition and injectionfluid were analyzed. Other parameters were fiercely influenced by back-pressure, whichshould be paid more attention to during site application.It can been seen that from field experiments, the program can meet the needs ofdifferent kinds of oil wells, sand-flushing with foam fluid can effectively preventleaking, and set up cycle of oil tube and annular space successfully. After sand-flushingoperation, oil production can be recovered soon, and output of oil wells can be increased. In conclusion, sand-flushing with foam fluid is a kind of effective method to removebottom-hole sand of low pressure oil wells. The thesis results are significant to perfectthe sand-flushing theory with foam fluid and instruct field application.更多还原