双重交联凝胶型堵剂的配方优选与选择性堵水机理研究

发布时间：2018-02-04 02:34

本文关键词： 双重交联选择性堵剂堵水机理　出处：《东北石油大学》2017年硕士论文　论文类型：学位论文

【摘要】：我国油田现在己进入高含水开发后期,油井出水现象严重,产油量剧减,含水率上升,从而导致“水淹”。针对低渗透性裂缝油藏堵水成功率低,选择性差等问题,提出用双重交联聚合物凝胶的观点进行选择性堵水剂的设计,提高堵剂交联度,增加堵剂的选择性,指导与优化内网络聚合物在地面条件下,进行一次交联,而后注入地层在高温下外网络聚合物进行二次交联,最终形成了高强度的双重交联凝胶型选择性堵水剂。本文首先对双重交联凝胶体系进行研究筛选,选择有机铬交联剂作为一次交联凝胶体系的交联剂,超支化聚丙烯酰胺作为一次交联体系聚合物主剂,酚醛树脂体系作为二次交联凝胶体系的交联剂,阳离子聚丙烯酰胺作为二次交联凝胶体系的交联主剂。经过实验配方优选,得到双重交联凝胶型堵剂配方:1000mg/L超支化聚丙烯酰胺+300mg/L内网络交联剂+800mg/L稳定剂+2000mg/L阳离子聚丙烯酰胺+2000mg/L外网络交联剂+150mg/L增强剂,并对体系性能进行评价。最后,本文对双重交联凝胶型堵剂的选择性堵水机理进行分析:1.双重交联体系网格孔隙较密、结构层次丰满,外网络填充在内网络的空隙中,凝胶的保水性和粘弹性非常好;2.并联岩心模拟实验得知,双重交联凝胶可以根据裂缝渗透率的大小而选择性进入,有良好的选择性,主要封堵大裂缝地层,该体系的堵水率远远大于堵油率;3.该凝胶体系的高封堵性能来自物理堵塞和表面吸附,岩石表面润湿性主要影响凝胶体系的表面吸附;4.双重交联凝胶在模拟地层水中具有很高的膨胀度,吸水膨胀后的凝胶在原油中具有很高的收缩率。通过分析双重交联凝胶体系初始阶段及最终阶段的成胶效果和高效封堵机理,探讨其选择性堵水机理,为双重交联凝胶型堵剂的应用提供理论支持,为油田的高产稳产提供技术支撑。
[Abstract]:At the late stage of high water cut development in China's oil fields, the phenomenon of oil well effluent is serious, the oil production is greatly reduced, and the water cut is increased, which leads to "water flooding". The success rate of water shutoff in low permeability fractured reservoirs is low. In order to improve the crosslinking degree of water plugging agent, improve the selectivity of plugging agent, and guide and optimize the inner network polymer under the ground conditions, this paper puts forward the idea of using double crosslinked polymer gel to design the selective water plugging agent. The first crosslinking is carried out, and the secondary crosslinking is carried out by injecting the formation into the outer network polymer at high temperature. Finally, a high strength double crosslinked gel selective water plugging agent was formed. Firstly, the double crosslinked gel system was studied and screened, and organic chromium crosslinking agent was selected as the crosslinking agent of the primary crosslinking gel system. Hyperbranched polyacrylamide was used as the main polymer agent of the primary crosslinking system and phenolic resin system as the crosslinking agent of the secondary crosslinked gel system. Cationic polyacrylamide was used as the main crosslinking agent in the secondary crosslinking gel system. The formulation of double crosslinking gel plugging agent:: 1000mg / L hyperbranched polyacrylamide 300mg / L network crosslinking agent 800 mg / L stabilizer. 2000mg / L Cationic Polyacrylamide 2000mg / L external Network Crosslinking Agent 150mg / L Enhancement. Finally, the selective water plugging mechanism of double crosslinked gel type plugging agent was analyzed. The gel has good water retention and viscoelasticity when the outer network is filled in the inner network. 2. The parallel core simulation experiment shows that dual crosslinked gel can selectively enter according to the size of fracture permeability, and has good selectivity, mainly plugging the formation of large fracture. The water plugging rate of this system is much higher than that of oil plugging rate. 3. The high plugging performance of the gel system comes from physical plugging and surface adsorption, and the wettability of rock surface mainly affects the surface adsorption of the gel system. 4. Double crosslinked gel has high swelling degree in simulated formation water. The gel after water absorption and expansion has a high shrinkage in crude oil. The mechanism of selective water plugging is discussed by analyzing the gelation effect and high efficiency plugging mechanism in the initial and final stages of the double crosslinked gel system. It provides theoretical support for the application of double crosslinked gel plugging agent and provides technical support for high and stable oil production.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE358.3

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