致密气藏储层“干化剂”抗盐作用改进与效果评价  

Study on Improvement and Effect Evaluation of Salt Resistance of“Drying Agent”in Tight Gas Reservoir

作　　者：熊钰[1] 傅希桐 张烈辉[1] 孙阳[1] XIONG Yu;FU Xitong;ZHANG Liehui;SUN Yang(National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu,Sichuan 610500,China)

机构地区：[1]油气藏地质及开发工程全国重点实验室·西南石油大学,四川成都610500

出　　处：《西南石油大学学报（自然科学版）》2023年第4期85-93,共9页Journal of Southwest Petroleum University(Science & Technology Edition)

基　　金：四川省应用基础研究项目(2019YJ0424)。

摘　　要：目前,储层含水饱和度高是导致致密气藏渗透率低的主要原因,已有研究指出,向致密储层孔隙中注入能与地层水发生化学反应的干化剂可以降低含水饱和度。但通过注入干化剂降低含水饱和度的方式可能会遇到反应所产生的固相盐析物,造成孔隙的堵塞,因此,在前期研究干化剂的基础上降低盐析物的生成,改进干化剂配方尤为重要。研究引用了一种含锂离子的金属碳化络合物LCN作为协同剂,参与复合干化剂配方的干化反应,主要作用于改进干化剂配方的抗盐效果,减少干化反应后的固相盐析物,并通过分析反应中各种化学物质的反应热,结合实验,对比改进后的复合干化剂与原干化剂在反应后的热效应及其干化效果变化。并且通过对盐析物进行XRD的物相分析结果,选择能与金属阳离子络合的EDTA与DTPA作为抗盐辅助剂,分别在常温常压与模拟地层高温高压的实验条件下进行了抗盐效果研究,实验结果表明,通过加入协同剂LCN与抗盐辅助剂使得干化剂体系达到较为理想的抗盐效果,即在耗水最多的同时产生的固相盐析物最少,使得干化剂体系更加完善。At present,the high water saturation of the reservoir is the main reason for the low permeability of the tight gas reservoir.It has been pointed out that the desiccant which can react with the formation water to reduce the water saturation has been injected into the pores of the tight reservoir.However,the way of reducing water saturation by injecting desiccant may encounter the solid salting out produced by the reaction,resulting in pore blockage,so it is particularly important to reduce the formation of salting out on the basis of the previous study of desiccant.It is particularly important to improve the formula of desiccant.A metal carbonization complex LC containing lithium ion was used as a synergistic agent to participate in the drying reaction of the compound drying agent formula,which mainly improved the salt resistance effect of the drying agent formula,greatly reduced the formation of solid phase salting-out after the drying reaction,and analyzed the reaction heat of various chemical substances in the reaction.Combined with the experiment,the thermal effect and drying effect of the improved composite drying agent and the original drying agent were compared.Based on the results of XRD phase analysis of the salting out,EDTA and DTPA,which can complex with metal cations,were selected as salt resistance auxiliaries,and the salt resistance effects were studied under the experimental conditions of normal temperature,normal pressure and simulated formation high temperature and high pressure.the experimental results show that the desiccant system can achieve ideal salt resistance effect by adding synergist LC and salt resistance auxiliaries.That is to say,when the water consumption is the most,the solid salting out is the least,which makes the drying agent system more perfect.

关 键 词：致密气藏 水锁 干化剂 抗盐改进 协同剂 

分 类 号：TE39[石油与天然气工程—油气田开发工程]