蒙古林油田调驱后进一步改善水驱开发效果研究

发布时间：2018-04-03 10:00

  本文选题：蒙古林油田　切入点：弱凝胶调驱　出处：《成都理工大学》2015年硕士论文

【摘要】：弱凝胶调驱技术可以提高注水开发效果,近年来在油田获得了广泛应用。蒙古林砂岩油藏于1989年10月投入开发,到2002年12月底,累积产油258.14×104t,综合含水为92.90%。自2002年5月开始,油田采用弱凝胶调驱来提高采收率,直至08年10月完成调驱。调驱后,采出程度仅增加3.26%,剩余可采储量189.52×104t,区块仍有大量剩余油存在,具有进一步改善水驱开发效果的潜力。因而,在室内试验的基础上,利用数值模拟手段,对比研究调驱前后纵向及平面剩余油分布特征,并结合地质特征及油田开发实际,提出进一步改善水驱开发效果的方案,以提高最终采收率。弱凝胶调驱室内试验结果表明,弱凝胶对单个油层的封堵能力随油层渗透率增大而减小,当渗透率小于20×10-3μm2时,对油层的封堵能力达到了98%以上;随着渗透率级差增大,弱凝胶对高渗层封堵能力增大,对低渗层封堵能力减小,当渗透率级差大于4.3时,低渗管分液量大于高渗管分液量;弱凝胶对油相有一定程度的封堵,但封堵能力远小于对水相的封堵能力,当水驱至30PV时,水相封堵率下降;随着胶体老化,弱凝胶封堵性能降低,当老化时间大于80d时,弱凝胶封堵率下降明显。纵向及平面剩余油及剩余油分布特征研究表明,调驱后总体上吸水剖面得到改善,这也与室内试验得出的结论一致,但改善效果不明显。也正因为如此,才有很多剩余油且分布不均,使调驱后有改善水驱开发效果的改善条件及潜力。T1ys1-1小层剩余地质储量相对较少,为82.89×104t,且目前含水率高,为90.22%,不是进一步水驱开发的主力层;T1ys1-2-1小层剩余地质储量略高于T1ys1-1小层,为95.15×104t,但目前含水率低,为81.64%,可考虑作为进一步开发的主力层;T1ys1-2-2小层及T1ys2-1小层剩余地质储量较多,分别为176.70×104t及251.21×104t,且含水率不高,分别为91.18%及91.97%,是进一步开采的主力层;T1ys2-2小层及T1ys2-3小层剩余地质储量最多,分别为251.21×104t及278.81×104t,但含水率较高,分别为94.82%及95.46%,要在控制含水上升率的情况下进一步开采。平面上剩余油主要分布在小断层遮挡带附近、局部构造高部位、南部边部及井网未受控制区。预测结果表明,周期注水与完善井网增油效果较好,为此将周期注水与完善井网叠加后形成综合开发方案,进一步研究对全区最终采收率及水驱开发效果的影响。预测结果表明,到2054年9月21日综合含水上升到98%时,全区累积注水5599.45×104m3、累积产油489.22×104t、最终采收率33.65%。2014年5月27日到2054年9月21日期间,全区阶段注水2574.31×104m3、阶段产油108.44×104t、阶段采出程度7.46%、阶段含水上升率1.00%、阶段平均综合递减率6.40%、阶段平均自然递减率6.40%。与2013年相比,阶段平均综合递减率下降3.63个百分点,阶段平均自然递减率下降8.14个百分点。与未进行综合开发相比,累积注水量增加979.81×104m3、增油71.82×104t、最终采收率增加4.94%。
[Abstract]:Weak gel control flooding technology can improve the effect of water injection development and has been widely used in oil fields in recent years.The Mongolian sandstone reservoir was put into development in October 1989, and by the end of December 2002, the cumulative oil production was 258.14 脳 10 ~ 4 t, and the comprehensive water cut was 92.90 t.Since May 2002, weak gel flooding has been used to improve oil recovery, until October 2008.After adjusting and flooding, the recovery degree increases only 3.26%, the remaining recoverable reserves are 189.52 脳 10 ~ 4 t, and a large number of remaining oil still exist in the block, which has the potential to further improve the development effect of water flooding.To improve the final recovery.The results of laboratory test of weak gel flooding show that the plugging ability of weak gel decreases with the increase of reservoir permeability. When permeability is less than 20 脳 10 ~ (-3) 渭 m ~ (2), the plugging ability of oil layer reaches more than 98%, and the plugging ability increases with the increase of permeability.When the permeability difference is greater than 4.3, the liquid fraction of the low permeability tube is larger than that of the high permeability layer, and the weak gel has a certain degree of plugging to the oil phase, while the plugging ability of the weak gel to the high permeability layer increases, and the plugging ability of the weak gel to the low permeability layer decreases.However, the plugging ability is much less than that of water phase. When water drives to 30PV, the plugging efficiency of water phase decreases, and with the aging of colloid, the plugging performance of weak gel decreases, and when the aging time is more than 80 days, the plugging rate of weak gel decreases obviously.涓，

本文编号：1704706