高温高盐产水气藏微胶堵水封堵特性实验  

Blocking characteristics of microgel in high-temperature and high-salinity water producing gas reservoirs: An experimental study

作　　者：林仁义 罗平亚[1] 孙雷[1] 潘毅[1] 焦宝雷 

机构地区：[1]西南石油大学 [2]中国石油化工股份有限公司西北油田分公司

出　　处：《天然气工业》2018年第3期69-75,共7页Natural Gas Industry

基　　金：国家科技重大专项"超深层低渗气藏有效开发技术"(编号:2016ZX05015-005)

摘　　要：针对我国西北地区THN、S3、KL等深层高温高盐(井深超过5 000 m,温度140℃,矿化度20×10~4 mg/L)砂岩有水气藏,现有的常规堵水和选择性堵水技术难以有效解决气井排水采气和有效堵水恢复气井产能的问题。为此,有针对性地研制和筛选了能够在高温高盐条件下实现二次交联的丙烯酰胺微胶体系WJ-1,并进行了一系列堵水性能评价实验,包括注入压力、阻力系数、耐冲刷性及对气水两相渗透率的影响等。通过实验证实了微胶体系WJ-1成胶后的抗温抗盐特性良好,能达到THN、S3、KL等高温高盐深层产水气藏深部堵水的要求,该堵剂成胶后能有效封堵高渗孔道中的水侵,让气体的通过能力明显大于水的通过能力,表明注入微胶体系WJ-1能起到一定的"堵水不堵气"的效果。此外,进一步对WJ-1微胶体系的孔隙结构特征开展了核磁共振实验分析,测试了岩心中注入WJ-1微胶体系封堵后的T2谱图,结果显示其对水的封堵强度明显大于对气的封堵强度,进一步证实了所研制堵剂的选择性封堵能力。The effective countermeasures of drainage gas recovery and water blocking for productivity recovery of gas wells in wa- ter-bearing high temperature, high salinity （HT/HS） deep gas reservoirs （well depth greater than 5 000 m, temperature 140℃ and salinity 20×10^4 mg/L） in the northwestern China, such as THN, $3 and KL cannot be realized by the existing conventional means. In this paper, an acrylamide microgel system WJ-1 that can realize the secondary cross linking in such conditions like high temperature and high sa- linity was specially developed and screened. Then, a series of experiments were conducted to test its capacity of water shut off, including injection pressure, resistance coefficient, flushing resistance and their influence on the gas-water two-phase permeability. It is experi- mentally confirmed that this microgel system WJ-1 after gelling behaves well at high-temperature and high-salinity resistance and can realize in-depth water blocking in deep HT/HS water producing gas reservoirs, such as THN, $3 and KL. After gelling, it can block the water invasion of high-permeability pore passages effectively, and consequently the gas passing capacity is much higher than water pass- ing capacity. It is indicated that the microgel system WJ-1 can, to some extent block water instead of gas. In addition, nuclear magnetic resonance experiment was conducted to study the pore structure characteristics of microgel system W J-l, and the T2 curves after WJ-1 was injected into the core for blocking were verified. It is shown that its water blocking strength is stronger than its gas blocking strength, which further demonstrated that the microgel system WJ-1 is effective in selective blocking.

关 键 词：产水气藏 高温高盐 微胶堵水 封堵强度 核磁共振 实验堵水不堵气 选择性封堵 

分 类 号：TE358.3[石油与天然气工程—油气田开发工程]