初探油气田开发中物理采油技术

油气田开发的任务就是尽可能经挤、合理地提高地下油气的采出程度，即提高石油采收率．纵观原油生产的垒过程，其实就是一个不断提高采收率的过程。在原油生产的第一阶段（一次采油），原油是利用天然能量来开采的，其最终采收率一般只能达到15％左右。当天然能量衰竭时，通过注水向油层提供补充能量，即开始了开采的第二阶段（一次采油）。它的采收率远比能量衰竭法高，最终采收率通常为30％～40％。当该油田的水油比接近作业的经济极限时，即产出油的价值与水处理及其注入费用相差太小，而使纯收益减少时，则进入了三次采油的阶段，这个阶段被称为提高原油采收率。     

毛家河油田注水开发可行性研究

毛家河油田利用天然能量开发,其驱动方式主要包括弹性驱动和溶解气驱动,这两种驱动方式的最终采收率只有10%,当压力降到一定程度以后,就要采用注水补充能量保持油藏压力的开发方式。文中首先对地层能量进行了分析,随后对注水开发可行性进行了分析,分析表明毛家河井区采用注水开发的方式是可行的。     

陕北油田注水开发对油层的损害及保护的综合探究

以陕北油田定边采油厂油房庄油区为研究对象,研究注水开发过程对影响效果的主要因素进行分析,注水技术是把水注入油层,以补充和保持油层压力的措施。为了弥补原油采出后所造成的地下亏空,保持或提高油层压力,实现油田高产稳产,并获得较高的采收率,必须对油田进行注水。     

浅析子长油矿降沟站注水工作

一个油田油层是根本,压裂是手段,注水是关键。依靠注水开发可以有效的补充地层能量,提高单井产量和最终采收率。降沟区注水井网还不规范,直接影响到注水的整体效果,还必须完善注采井网充分发挥注水的作用,进一步提高原油采收率。     

河川南湾油区长6油层注水开发的可行性分析

河川南湾油区位于鄂尔多斯盆地西部,其主力油层为长6油层。截至目前,区块未进行注水等措施补充地层能量,地层能量亏空严重,压力下降快,从而造成储层天然及人工裂缝闭合,油流不能有效进入井筒,单井产油能力下降,含水上升。为能够进行区块高效开发、进一步提高区块采收率,急需对区块进行注水开发。本次对研究区长6储层注水开发可行性进行论证,为下一步注水开发奠定理论基础。研究区储层砂体连通性好,胶结物以方解石、绿泥石为主要成分,菱铁矿和硅质胶结物占次要。敏感性试验结果表明,本区属于中等速敏、弱水敏、中等偏弱盐敏、弱酸敏、弱碱敏、弱亲水性特征。水驱油试验显示该区长6油层无水期驱油效率平均41.8%,最终驱油效率平均58.2%,有利于注水开发。根据理论计算及相关邻区注水开发实践预测本区水驱采收率比天然能量采收率高9%。由此可见,本区域储层适合注水开发,采用注水开发,可有效地提高研究区长6油层最终采收率,为油田带来可观的经济效益。     

鄂尔多斯盆地王渠则地区延安组延9油藏注水开发论证及部署

鄂尔多斯盆地王渠则区侏罗系延安组延9油层组为研究对象,在油藏地质条件研究、精细储层描述及油藏开发中存在的问题研究基础上,通过注水开发适应性、注水方式和注水时机的分析,对延9油藏进行了注水开发部署,以期提高油藏最终采收率。研究认为：王渠则区延9油藏自然能量较低,天然能量采收率不到13％,而理论计算水驱采收率为30％左右,明显优于采用天然能量开采。同时该区储层连通性较好及中等酸敏、弱或无速敏、中等水敏,有利于注水进入地层。本次方案共新部署采油井32口,注水井5口,转注采油井23口。     

油田注水开发方面后期提高采油率的有效途径及方法研究

通过注水井把水注入油层，以补充和保持油层压力的措施称为注水；油田实际开发后，会在开采时间的延长下，油层本身能量将不断被消耗，进而引起油层压力不断下降，地下原油大量脱气，粘度增加，降低了油井产量，严重者将发生停喷停产，致使地下残留的死油无法采出，为了有效处理原油采出后而引起的地下亏空，稳定或提高油层压力，确保油田的高产量及良好的采收率，就需要对油田进行注水。     

葡南扶余特低渗透油田注水开发规律探讨

葡南扶余油田注水开发实践表明:油层吸水能力差,注水压力高,注水开发效果差,采收率低;又由于该类油层中天然裂缝的普遍发育,加剧了油层平面的非均质性,给油田注水开发带来了许多因难,本文针对扶余油层开发中的主要矛盾,对注水开发问题进行了探讨,提出了适合扶余油层开发特点的注水调整对策,改善注水状况,优化水动力学驱油方法,为下一步开发扶余油层做好工作。     

通达山区长6油层注水开发可行性论证

通达山区长6油层目前主要以自然能量开采为主,仅在区块南部有15口注水井。区块注采井网不完善,地层压力保持水平低,仅为35.4%,地下亏空严重。研究区目前日产油量小于0.1t的油井占开井数的58.3%,低产低效井比例大。大量的低产低效井导致区块采油速度低,采出程度小,目前仅为5.33%。储层有丰富的剩余油及可观的开发潜能。区块油层连通性好,储层敏感性试验显示适合注水开发。因此,区块急需开展注水开发工作,尽早补充地层压力,提高油井采油速度,最终达到提高采收率的目的。     

油田注水开发工艺技术探讨

油田注水开发是为油层补充能量的方式,通过水驱油的作用,提高油井的产能,达到油田开发的目标.因此有必要研究油田注水开发的工艺技术措施,达到最佳的水驱开发效果,满足油田开发的需要,不断提高油田的产能,为油田开发创造最佳的经济效益。     

Experimental study of secondary and tertiary modes combined low salinity water and polymer flooding in sandstone porous media

Combined low salinity water (LSW) and polymer (LSP) flooding is the most attractive method of enhanced oil recovery (EOR). Considerable research has investigated effective mechanisms of LSP flooding. In this study, 10 laboratory core flood tests were carried out to evaluate the effects of LSW injection into samples without any clay particles, the timing of LSW injection, and the advantages of adding polymer to the injection water for EOR. Secondary and tertiary LSW injections were performed on sandpack samples with different wettability states and water salinity. Tertiary LSW injection after secondary synthetic seawater (SSW) injection in oil-wet samples resulted in 13% more oil recovery, while the water-wet sample showed no effect on the oil recovery. Secondary LSW injection in oil-wet porous media improved oil recovery by 8% of the original oil in place (OOIP) more than secondary SSW injection. Tertiary LSP flooding after secondary SSW injection in the oil-wet sample provided a recovery of 67.3% of OOIP, while secondary LSW injection followed by tertiary LSP flooding yielded the maximum ultimate oil recovery of about 77% of OOIP. The findings showed that the positive EOR effects of LSW and LSP flooding were the results of wettability alteration, pH increase, improved mobility ratio, better sweep efficiency, and oil redistribution. In addition, results showed that wettability alteration is possible without the presence of clay particles. The findings of this study can help for a better understanding of fluid propagation through the porous media and an investigation of delays in reaching ultimate oil recovery.     

注蒸汽热采技术研究进展

在研究大量文献的基础上,总结了注蒸汽采油的机理,概述了稠油注蒸汽热采的研究现状与发展趋势,着重探讨了稀油注蒸汽热采的应用前景、研究现状以及稀油注蒸汽热采还需要深入研究的课题。研究认为：稠油注蒸汽热采已是比较成熟的技术,在稠油开发中占有重要的地位,其发展趋势为利用天然气、溶剂、高温泡沫、聚合物等来改善注蒸汽热采效果;稀油油藏水驱、聚驱后转注蒸汽热采具有可行性,今后需重点解决的问题包括采用煤或核能生产蒸汽、采用水汽交注、蒸汽泡沫等方法提高稀油油藏注蒸汽热采的采收率。     

牛圈湖油田西山窑低压油藏超前注水矿场试验研究

牛圈湖油田西山窑油藏是低孔特低渗低压油藏,油井自然产能低,通过压裂、水平井技术不能有效提高单井产量,达不到经济开发的要求。随着近几年研究的深入,决定以超前注水为主体思路,对牛圈湖西山窑油藏的开发开展重点评价,通过超前注水,提高地层压力系数,辅助水平井、压裂等增产措施,提高单井产量,单井初期产量从1．8t／d提高到11t／d,产能提高了6．1倍,达到经济界限要求,使难采储量得到经济有效动用,为三塘湖盆地低压油藏储量升级动用奠定了基础。     

注N_2开发有水气藏中的微观实验研究

有水气藏的水侵造成大量气体封存在储层中,其采收率仅为30～50%。本文从微观实验角度出发,探索注N2提高有水气藏采收率方法。在均质孔隙模型中进行N2驱天然气和水实验,气驱前沿主要表现形式为跳跃式的运移和粘性指进。实验中,平均气驱效率为68.62%。在裂缝～孔隙模型中进行N2驱天然气和水实验,N2优先选择较好的渗流通道流动,可以有效补充模型中天然气的能量,形成气体活塞,驱动裂缝中的水流动。实验中,平均气驱效率为64.63%。认为注N2开采能有效提高有水气藏的开采效果。     

二氧化碳驱波及系数和驱油效率研究

油田开发中注入介质的驱替效率和波及系数决定了最终采收率,目前二氧化碳驱替能够明显提高油田采收率,所以采用物理模拟和数值模拟的方法对比水驱和二氧化碳驱替中二者的不同,加深认识二氧化碳驱油机理.     

SIMULTANEOUS HEAT AND FLUID FLOW IN POROUS MEDIA: CASE STUDY: STEAM INJECTION FOR TERTIARY OIL RECOVERY

Heat transfer and fluid flow in porous media occur simultaneously in thermal enhanced oil recovery and significantly increase the rate of energy transfer. The purpose of this investigation was to take advantage of such contemporary transfers and to study heavy oil recovery efficiency using hot-water flooding, cold-water flooding, and steam injection into porous media. A set of multistage laboratory tests was performed to find the temperature profile during steam injection as a means of tertiary oil recovery. Sand-packed models were utilized to investigate the oil recovery efficiency during cold and hot water injection as well as steam flooding for both secondary and tertiary oil production stages. An oil bank was formed in steam injection during the tertiary oil recovery from a vertical standing sand-packed model, resulting in very high oil recovery efficiency. Steam injection was found to be very effective, compared to cold- and hot-water flooding, for the recovery of heavy oil. Based on the principles of transport phenomena in porous media, a mathematical model was developed to predict the temperature profile during the steam injection process. Satisfactory agreement is achieved between the temperature profile predicted from the model and the experimental results.     

SIMULTANEOUS HEAT AND FLUID FLOW IN POROUS MEDIA: CASE STUDY: STEAM INJECTION FOR TERTIARY OIL RECOVERY

Heat transfer and fluid flow in porous media occur simultaneously in thermal enhanced oil recovery and significantly increase the rate of energy transfer. The purpose of this investigation was to take advantage of such contemporary transfers and to study heavy oil recovery efficiency using hot-water flooding, cold-water flooding, and steam injection into porous media. A set of multistage laboratory tests was performed to find the temperature profile during steam injection as a means of tertiary oil recovery. Sand-packed models were utilized to investigate the oil recovery efficiency during cold and hot water injection as well as steam flooding for both secondary and tertiary oil production stages. An oil bank was formed in steam injection during the tertiary oil recovery from a vertical standing sand-packed model, resulting in very high oil recovery efficiency. Steam injection was found to be very effective, compared to cold- and hot-water flooding, for the recovery of heavy oil. Based on the principles of transport phenomena in porous media, a mathematical model was developed to predict the temperature profile during the steam injection process. Satisfactory agreement is achieved between the temperature profile predicted from the model and the experimental results.     

Microfluidic study of surfactant flooding of heavy oil in layered porous media containing fractures

Surfactant injection is a promising method for enhanced oil recovery (EOR) due to its effective micro-displacement mechanisms. However, understanding the interaction of a surfactant solution with heavy oil in porous media is neither straightforward nor well understood, particularly in heterogeneous systems. By enabling in-situ real-time monitoring of flow transport, microfluidic studies have provided novel insights into the underlying multiphase physics of flow at the pore scale. This paper examines the two-phase displacement efficiency of a new surfactant in layered–fractured porous microfluidic patterns, a topic seldom discussed in the literature. To evaluate the performance of the proposed surfactant, we considered several heterogeneous media with varying layer and fracture geometrical characteristics, quantifying displacement efficiency for each case. Based on the analysis of pore-scale snapshots, it was inferred that the primary mechanisms responsible for EOR during surfactant flooding into heavy oil include pore wall transportation, emulsifications, the deformation of residual oil, inter-pore or intra-pore bridging, and wettability alteration. Macroscopic displacement experiments revealed that the width of the swept area from surfactant injection significantly exceeded that of water injection, resulting in a substantially higher oil recovery. Furthermore, it was demonstrated that the direction of fluid flow in relation to fracture orientation plays a critical role in the dynamics of surfactant solution movement and, consequently, the ultimate oil production.     

改善复杂河流相稠油油田水驱开发效果对策

复杂河流相油田由于先天地质条件复杂,砂体连通性难以把握,同时海上开发这类油田仍以大井距多层合采为主,加剧了注采间矛盾。以渤海B油田为例,通过油藏工程方法评价油田注水开发存在的问题,然后选取典型井组通过油藏数值模拟方法,开展注水井排液时间及合理转注时机、合理注采比、合理油水井数比等方面优化工作,提出该类油田设计注水井排液1~2年后应适时转注,合理注采比应保持在0.9左右,油水井数比保持在1.4左右,同时应优化注采井网,考虑在物性较差的河道边部部署注水井,在物性较好的河道中部部署采油井,提高注入水利用效率改善水驱开发效果。