泥灰岩储层缝网裂缝导流能力优化研究

发布时间：2018-04-05 10:25

  本文选题：泥灰岩　切入点：体积酸压　出处：《中国科学院研究生院(渗流流体力学研究所)》2015年硕士论文

【摘要】：华北油田束鹿凹陷泥灰岩致密油储层埋藏深、岩性复杂、天然裂缝发育,既不同于北美bakken致密油,又不同于国内松辽、鄂尔多斯长7储层特征,储层改造的难度极大,在以往井改造中呈现“见效明显,难稳产”的特点,需要探索一套适合泥灰岩储层的体积改造模式。鉴于以上问题,本论文以泥灰岩储层缝网裂缝导流能力优化作为研究对象,围绕着缝网裂缝导流能力形成、保持和匹配三方面展开系统的研究,取得以下研究成果：(1)利用考虑启动压力梯度的油藏数值模拟方法开展了泥灰岩储层特性与缝网系统主、支缝导流能力匹配关系优化研究；依据泥灰岩储层实际地质模型,优化出泥灰岩储层最优主缝半缝长为180m,最优的主、支缝导流能力分别为30pm2.cm和2pm2.cm。(2)利用旋转圆盘仪器开展了泥灰岩与普通酸、VES自转向酸和胶凝酸三种酸液体系酸岩反应动力学研究,建立了130℃高温条件下三种酸液体系与泥灰岩的酸岩反应动力学方程,较纯灰岩酸岩反应级数低1-2数量级。(3)以裂缝充填程度为主线,利用岩心流动实验结合CT扫描及电镜扫描技术研究了完全充填裂缝(钙质充填)、部分充填及复杂裂缝条件下酸液对裂缝沟通特征。认识到单纯的酸液溶蚀作用很难实现非连通裂缝体统的沟通,需要水力造缝与酸溶蚀相结合以实现最大程度的缝网改造。(4)研究了VES自转向酸不同注入速率下泥灰岩酸蚀裂缝导流能力及保持能力。认识到泥灰岩储层单纯依靠酸压改造难以形成足够的裂缝导流能力,应该采取体积酸压+加砂压裂复合改造模式,且应遵循“压裂为主,酸压为辅”的设计理念。(5)建立了复杂缝网下主、支缝支撑裂缝导流能力研究新方法,开展了泥灰岩储层在不同裂缝宽度、不同规格支撑剂组合、不同支撑剂铺置方式下支撑裂缝导流能力研究。认识到对于支缝(1mm缝宽表征),采用70/100目实现天然裂缝堵与疏的结合；对于主缝(3mm和5mm表征),采用多种粒径支撑剂组合的方式进行充填,以提高主缝导流能力及保持能力稳定性。
[Abstract]:The dense oil reservoir of mudstone in Shulu sag of North China Oilfield is deeply buried, complex lithology and natural fracture development, which is different from bakken tight oil in North America and the characteristics of Songliao reservoir in China and Chang7 reservoir in Ordos Basin, so it is very difficult to reconstruct the reservoir.In the former well reconstruction, the characteristics of "obvious effect and difficult stable production", need to explore a suit of volume transformation model suitable for marl reservoir.In view of the above problems, this paper takes the optimization of fracture conductivity in marl reservoir as the research object, focusing on the formation, maintenance and matching of fracture conductivity.The following research results are obtained: 1) based on the reservoir numerical simulation method considering the starting pressure gradient, the optimization of the matching relationship between the shale reservoir characteristics and the main and branched fracture conductivity of the fracture network system is carried out, and according to the actual geological model of the marl reservoir,The kinetic equation of acid rock reaction between three acid systems and marl at 130 鈩，

本文编号：1714364