低渗强水敏油藏注水开发防膨工艺研究

【作者】 胡学雷；

【导师】 张烈辉； 张学鲁；

【作者基本信息】 西南石油学院 ， 油气田开发工程， 2003， 硕士

【摘要】 车排子油田车2区齐古组油藏属于低渗透率强水敏油藏。从目前国内外低渗透率油藏和强水敏油藏的开发来看，由于低渗透率油藏比中高渗透率油藏的物性差很多，在其开发过程中会遇到更多的难题。对于象车2区齐古组这样低渗强水敏油藏的开发，在新疆油田范围内没有可借鉴的先例。因此高效地开发该油田，提高最终采收率，获得最大的经济效益，是我们全体开发人员共同的奋斗目标。 本文主要阐述了车排子油田车2区齐古组油藏注水开发的可行性和注水开采的工艺技术的研究，注水开发方案的实施及开发效果评价。本文应用地层层序学、地质统计学及地球物理勘探三大地质理论，进行了高精度三维地震解释和油藏精细描述等工作，对油藏构造、断裂、沉积相、储层、储量、油水分布等进行了解释，最终建立了油藏三维地质模型。运用美国LANDMARK公司的VIP4.0黑油模型软件作为模拟器，从注水开采与天然能量开采、不同注水井点、不同注水强度、油藏的防膨等方面对对注水开发的可行性进行了模拟研究，结果表明该油田应立足于注水开发，且早注比晚注采出程度高，最终采收率对渗透率很敏感，注水应进行防膨，尽量减小渗透率损失。在该油藏的注水开采工艺技术方面：本文阐述了注入水水质标准的制定方法；从理论上研究得出了该油藏的破裂压力和最大注入压力；借助室内岩芯实验和现场实验进行了水敏性储层的保护与解堵技术研究，摸索出了水敏性储层保护和解堵的有效措施；运用常规油藏工程方法和室内岩芯物理实验、现场试注，对防膨剂添加浓度和方式进行了优化研究。新疆油田勘探开发研究院在没有相关注水开发资料的情况下，根据室内岩心试验，提出该油藏注水开发时注入水中需加入0.6％的防膨剂GY-2的建议，注入水仅加入的防膨剂成本就达57.6元／方；我们通过室内岩心试验、理论研究和现场的试注效果，大胆地提出0.6％、0.3％、0.15％的阶梯式加药方式，从现场的实施情况来看，收到了好的防膨效果，注水成本下降了43.2元/方，年节约注水成本357.1万元。我们还研究并提出了钻井、完井、修井等过程中的油藏保护措施，以及有效的油水井增产、增注措施。 经过三年的注水开发，车排子油田生产形势也得到扭转，车2区块日产水平稳中有升，由最低时的日产水平215吨上升到2001年底的262吨，自然递减由注水前的43%下降到2001年的一10.1%，注水开发取得了好的效果;同时也证明了注水的防膨工艺和油水井的增产、增注措施是成功的。更多还原

【Abstract】 Reservoir of Che 2 district Qigu formation in Chepaizi field has low permeability and strong water sensitivity. Reservoirs of this type encountered more difficulties during development because its characteristics were quite different between low permeability and high permeability. As no precedent could be used for reference in Xinjiang field, we had the very same aim to develop this field effectively, enhance ultimate recovery and acquire the maximum economy benefit.This article mainly depicted the feasibility, techniques research, application and evaluation of water injection scheme in Che 2 district Qigu formation of Chepaizi field. Using three geologic theories, stratigraphic sequence, geostatisties and geophysical exploration, we performed high-accuracy 3D seism explanation and precise reservoir description to explain reservoir constitution, rupture, sedimentary phase, oil layer, reserves and oil water distribution. And finally we established 3D reservoir geologic model. Simulation researches of water injection feasibility were carried out with LANDMARK’S VIP4.0 black-oil simulator from such aspects as waterflood and natural recovery, different water injection well and intensity, and reservoir swelling prevention. The results showed that development of this field should base on water injection and it is better to inject earlier than later. It also shows that ultimate recovery rate was closely related to the permeability. So measures should be taken to prevent the reservoir from swelling to reduce the loss of permeability. Also, this article depicted the method to draw up the standard of injected water quality, educed the fracture-pressure and maximum injection pressure of the reservoir through theoretical research, proceeded protection and breaking down techniques research of water-sensing reservoir through indoor core experiment and in situ experiment, achieved effective measures to protect and break down water-sensing reservoir, and performed consistency and mode optimization research of the swelling resistant medicament using general method of reservoir engineering as well asindoor core physical experiment and in situ trail-injection. Based on indoor core experiment and without related waterflood information, Xinjiang Oil Field Exploration and Development Research Institute gave the advice of adding swelling resistant chemical GY-2 with 0.2% to injected water when waterflood is required for the reservoir, and only the cost of the chemical would reach ￥57.6/m3. By indoor core experiment, theoretical research and in situ effect of trail-injection, we boldly address the step chemical injection scheme with the percentage 0.6%, 0.3% and 0.15%. In situ application results showed that due to this scheme, good antiswelling effect was achieved, injection cost reduced ￥43.2/m3 and ￥3,571,000 of injection cost were saved. Additionally, we addressed after research the measures of reservoir protection during drilling, completion and repairing, as well as effective measures of increasing production and injection.After 3 years’ waterflood, the situation of Chepaizi field’s production had been turned round. Exceeding from the lowest 215t/d to the end of 2001’s 262t/d, production became stable and increasing in Chepaizi district. Natural reduction declined from 43% before injection to 2001’s -10.1%, which indicated the good effect of waterflood. Also, it make known that the antiswelling techniques of waterflood and the measures of increasing production and injection were successful.更多还原