B21井区优势通道判别及对策研究

发布时间：2018-05-25 07:29

本文选题：注水开发 + 含水率高　；参考：《西南石油大学》2015年硕士论文

【摘要】：经过十几年到几十年的注水开发,目前大多数油田总体上都已进入高含水高采出程度阶段。在长期注水开发过程中,受储层非均质性、水油流度比及注采不平衡等因素的影响,注水开发油田储层中极易形成大孔道。在大孔道发育的地层中,注入水优先沿大孔道流动,驱油效率低甚至起不到驱油的作用而直接从油井中生产出来,造成注入水窜流和油井的过早水淹,而其它一些低渗部位很难受效,严重影响驱油效率,致使平面上剩余油饱和度差异明显。因此,砂岩油藏大孔道对储层渗透率及注采工艺有着重要的影响,严重影响了注水开发效果。因此发现和识别储层中的水流优势通道,并采取相应措施,对于改善注水开发效果,提高原油采收率具有重要的意义。本文针对B21井区百口泉组油藏注水开发过程中出现的一些矛盾,如储层非均质性较强、水窜严重等,在广泛调研大量国内外文献的基础上,综合前人的研究成果,通过深化地质认识,结合生产动态资料,对B21井区B1层系的优势通道的成因、识别及相应对策进行了研究,获得了以下成果： 1、百口泉组高含水区近年由于注水井井况变差,分注率、分注级别低,导致平面、剖面压力分布不均,潜力层动用程度降低,含水上升加快,递减加大,开发效果变差。 2、优势通道形成机理的核心是储层原始高孔、高渗透层段在高压水流冲刷、驱动力作用下,使储层岩石颗粒表面吸附的粘土矿物及粒间填隙物或胶结物发生溶蚀、剥离、携带、迁移的过程,并使粒间孔喉壁表变光滑、孔道扩大变粗,最终形成更高的孔、渗分布带。 3、结合优势通道在实际油藏开采中的表现,分析其形成机理、成因类型。影响优势通道形成的因素包括储层微观结构、储层物性、沉积相、油藏非均质性和开采方式等因素。优势通道形成的类别有：沉积微相控制、微裂缝网络连通、岩性沉积界面、储层改造、长期注水微颗粒迁移。 4、提出采用非均质综合指数、孔隙半径、沉积韵律和产(吸)液强度分析优势通道的方法,对百口泉组油藏水驱优势通道进行分析。先通过生产状况和产吸液剖面初步评判优势通道的发育情况,再通过沉积韵律、非均质综合指数和孔隙半径明确优势通道的发育等级,最后利用示踪剂监测和试井资料验证发育等级的准确性。B1层系优势通道主要集中在B12和B13砂组,其中1020A井组优势通道发育较好。 5、提出1020A井和1133井的调剖思路,并制定施工方案,进行了现场施工,措施后日产油增加了15.t/d,含水率下降6.4个百分点,两井组累计增油3116.1t从而验证识别结果的准确性。
[Abstract]:After more than ten years of water injection development, most oilfields have generally entered the stage of high water cut and high recovery. In the process of long-term water injection development, it is easy to form large pore channels in waterflooding oilfield reservoir due to the factors such as reservoir heterogeneity, water / oil mobility ratio and injection-production imbalance. In the formation with large pore development, injection water flows first along the large pore channel, and the oil displacement efficiency is low or even unable to play the role of oil displacement and is produced directly from the oil well, resulting in injection water channeling and premature flooding of the oil well. Some other low permeability parts are very uncomfortable, which seriously affect the oil displacement efficiency, resulting in significant difference in the remaining oil saturation on the plane. Therefore, the large pore passage of sandstone reservoir has an important influence on reservoir permeability and injection-production technology, which seriously affects the water injection development effect. Therefore, it is of great significance to find and identify the dominant channel of water flow in the reservoir and take corresponding measures to improve the effect of water injection development and oil recovery. In view of some contradictions in water injection development of Baikouquan formation reservoir in B21 well area, such as strong heterogeneity of reservoir, serious water channeling and so on, based on extensive investigation of a large number of domestic and foreign literature, this paper synthesizes the previous research results. By deepening geological understanding and combining with production dynamic data, the causes, identification and corresponding countermeasures of the dominant channel of B1 system in B21 well area are studied, and the following results are obtained: 1. In the high water-cut area of Baikouquan formation, due to the poor well condition, low injection rate and grade of injection in recent years, the plane and profile pressure distribution is uneven, the production degree of potential layer is decreased, the water cut rise is accelerated, the decline is increased, and the development effect becomes worse. 2. The core of the formation mechanism of the dominant channel is the original high porosity of the reservoir, the high permeability layer is washed by the high pressure water flow, and under the action of the driving force, the clay minerals adsorbed on the surface of the reservoir rock particles and the intergranular interstitial or cemented matter are dissolved, stripped off and carried. In the process of migration, the surface of the throat wall of the intergranular pore becomes smooth, the pore channel is enlarged and thickened, and finally a higher pore and permeability distribution zone is formed. 3. Combined with the performance of dominant channel in actual reservoir production, the formation mechanism and genetic type are analyzed. The factors affecting the formation of dominant channels include the microstructure of reservoir, reservoir physical properties, sedimentary facies, reservoir heterogeneity and exploitation methods. The types of dominant channels are: sedimentary microfacies control, microfracture network connectivity, lithologic sedimentary interface, reservoir transformation, long-term water injection microparticle migration. 4. The method of heterogeneity comprehensive index, pore radius, sedimentary rhythm and liquid intensity analysis is put forward to analyze the dominant channel of water drive in Baikouquan formation reservoir. First, the development of dominant channels is judged by production status and liquid absorption profile, and then the development grade of dominant channels is determined by sedimentation rhythm, heterogeneity comprehensive index and pore radius. Finally, the tracer monitoring and well testing data are used to verify the accuracy of the development grade. The dominant channel of the B1 series is mainly concentrated in the B12 and B13 sand groups, and the dominant channel of the 1020A well group is well developed. 5. The idea of profile control for well 1020A and well 1133 is put forward, and the construction scheme is worked out. The daily oil production is increased by 15.t / d, the water cut is decreased by 6.4 percentage points, and the accuracy of the recognition result is verified by the cumulative increase of 3116.1t in the two well groups.
【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】：TE357.6

【参考文献】