元284区块长6油藏多轮次调驱技术研究与应用

发布时间：2018-11-10 13:08

【摘要】：长庆油田元284区块长6油藏为超低渗透裂缝性油藏,基质渗透率在0.34-1.53mD之间,储层段砂岩裂缝视密度介于0.02-2.94条/m之间。该油藏在注水开发过程中油井单井产量低、产量递减快、井组见水方向性明显,且在实施深部调剖技术后,爬坡压力低,井组含水率下降不明显,现场应用效果不理想。本文针对区块开发现状,研究了适用于该油藏的多轮次调驱技术。对多轮次调驱体系进行优选与性能评价；利用数值模拟技术优化多轮次调驱注入参数并通过岩心流动实验对其进行评价；制作两种平面可视化模型对多轮次调驱机理进行初步探讨；对典型井组开展多轮次调驱的方案设计,并实施现场应用。本文取得以下研究成果： (1)调驱体系为预交联颗粒和弱凝胶的复合段塞。其中优化后的弱凝胶配方为：聚合物HPAM浓度1500mg/L+交联剂浓度100mg/L+调节剂TJ浓度100mg/L,成胶时间2-3d,成胶强度可控。室内评价实验表明,预交联颗粒和弱凝胶调驱体系具有良好的抗温性、抗盐性和较好的吸水剖面改善能力。体系注入方式和段塞尺寸为先注0.15PV预交联颗粒后注0.3PV弱凝胶。 (2)调驱参数优化实验中,在中含水阶段(40%-70%)进行多轮次调驱,井组增油效果会更好,所注弱凝胶在后续水驱的推动下沿高渗带不断突破并即将失效时开始下一轮次调驱,调驱效果最佳,最佳调驱轮次为三轮调驱。 (3)岩心流动实验中,多轮次调驱较单次调驱产生的爬坡压力更高、吸水剖面更均匀、调驱剂运移更规律、提高采收率更高(单次调驱可提高采收率17.98%、多轮次调驱可提高采收率26.8%)。 (4)多轮次调驱机理中,减小单轮调驱剂用量可提高封堵微小裂缝的几率、有效改善驱油路径并扩大波及效率。 (5)对元294-53井组进行了调驱方案设计并实施现场应用后,含水率从措施前的89.8%下降到措施后的79.8%,单井平均日产量从0.6t增加到1.14t。本文取得的多轮次调驱技术研究成果,对元284区块长6油藏提高采收率技术的现场应用具有一定的指导意义,并可对同类油藏调驱方案设计提供一定的借鉴作用。
[Abstract]:Chang6 reservoir in Yuan284 block of Changqing oilfield is an ultra-low permeability fractured reservoir with matrix permeability between 0.34-1.53mD and apparent fracture density of sandstone between 0.02-2.94 / m. In the process of water injection development, the single well production is low, the production decreases rapidly, the directivity of the well group is obvious, and after the deep profile control technology, the slope climbing pressure is low, the water cut of the well group is not obvious, and the field application effect is not ideal. In view of the current situation of block development, this paper studies the multi-cycle flooding technology suitable for this reservoir. The optimal selection and performance evaluation of multi-cycle control flooding system are carried out, and the injection parameters of multi-cycle modulation flooding system are optimized by numerical simulation technology and evaluated by core flow experiment. Two kinds of plane visualization models are made to discuss the mechanism of multi-cycle modulation flooding, and the scheme design of multi-round control drive for typical well groups is carried out, and the field application is carried out. In this paper, the following results have been obtained: (1) the control flooding system is a composite slug of pre-crosslinked particles and weak gels. The optimized weak gel formula is as follows: polymer HPAM concentration 1500mg/L crosslinking agent concentration 100mg/L modifier TJ concentration 100 mg / L gelation time 2-3 d gel strength controllable. The laboratory evaluation results show that the pre-crosslinked particles and the weak gel modified flooding system have good temperature resistance, salt resistance and the ability to improve the water absorption profile. The injection mode and slug size of the system were pre-mixed 0.15PV particles and then 0.3PV weak gel. (2) in the experiment of adjusting and flooding parameters optimization, in the middle water cut stage (40% -70%), the oil increasing effect of well group will be better, Under the promotion of subsequent water flooding, the injected weak gel continuously breaks through along the high permeability zone and is about to fail. When the next round of adjusting and flooding is started, the effect of adjusting and flooding is the best, and the best cycle is three rounds of modulation and flooding. (3) in the core flow experiment, the climbing pressure, the water absorption profile and the oil recovery are higher and more regular, and the oil recovery is higher in the multi-cycle modulation flooding than in the single modulation flooding, and the oil recovery is increased by 17.98%, the oil recovery is 17.98%, and the oil recovery is higher than that of the single modulation flooding, the water absorption profile is more uniform, and the displacement of the flooding agent is more regular. The oil recovery can be increased by 26.8%. (4) reducing the amount of single wheel control agent can improve the probability of plugging tiny fractures, improve the displacement path and expand the sweep efficiency. (5) the water cut of Yuan294-53 well group has been reduced from 89.8% before the measure to 79.8%, and the average daily output of single well has been increased from 0.6 t to 1.14 t. The research results obtained in this paper have a certain guiding significance for the field application of oil recovery enhancement technology in Chang6 reservoir of Yuan 284 block, and can be used for reference to the design of similar reservoirs.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE357

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