砾岩低渗透油藏注入水中固体悬浮物的伤害实验  

Damage experiment of suspended solids in injected water in low-permeability conglomerate reservoirs

作　　者：许世京 伍家忠[2,3] 史永兵 陈兴隆[2,3] XU Shijing;WU Jiazhong;SHI Yongbing;CHEN Xinglong(General Administration Department of China Petrochemical Corporation,Beijing City,100083,China;PetroChina Research Institute of Petroleum Exploration&Development,Beijing City,100083,China;State Key Laboratory of Enhanced Oil Recovery,Beijing City,100083,China;Chemical and Engineering Group Co.,Ltd.,PetroChina Changqing Oilfield Company,Xi’an City,Shaanxi Province,710018,China)

机构地区：[1]中国石化油田综合管理部,北京100083 [2]中国石油勘探开发研究院,北京100083 [3]提高石油采收率国家重点实验室,北京100083 [4]西安长庆化工集团有限公司,陕西西安710018

出　　处：《油气地质与采收率》2022年第4期116-121,共6页Petroleum Geology and Recovery Efficiency

基　　金：国家科技重大专项“低渗-超低渗油藏提高采收率新方法与关键技术”(2017ZX05013-003);国家自然科学基金青年基金项目“多孔介质内油-水-岩石多界面体系微观作用机理及应用研究”(51606222);中国石油天然气股份有限公司“十三五”重大科技项目“功能性水驱技术”(2016A-0903)。

摘　　要：砾岩低渗透油藏储层非均质性强、孔喉半径小、矿物成分复杂,在注水开发中,回注水中固体悬浮物含量和粒径大小成为导致储层伤害的主要因素,而现有碎屑岩低渗透油藏注水水质推荐指标难以满足砾岩低渗透油藏,因此,需根据砾岩低渗透油藏储层特点,制定科学的注水水质指标。根据砾岩低渗透油藏储层孔隙结构及黏土矿物特性,采用CT扫描、扫描电镜及X射线衍射等实验方法,多角度分析了该类油藏潜在的注水伤害主要因素,同时根据颗粒堵塞理论,在注入过程中注入水中的固体悬浮物(SS),会堵塞孔喉通道导致渗透率下降,从而对砾岩低渗透岩心造成严重伤害。实验结果表明,SS质量浓度和粒径中值对不同渗透率的砾岩岩心的储层伤害差异较大,若要实现目标区块储层伤害率≤20%,当储层渗透率小于等于9.28 mD时,SS质量浓度≤1.43 mg/L,粒径中值≤1.9μm;当储层渗透率大于9.28 mD但小于46.9 mD时,SS质量浓度≤3.1 mg/L,粒径中值≤2.6μm;而储层渗透率大于等于117 mD时,可放宽到SS质量浓度≤5.1 mg/L,粒径中值≤4.8μm。Low-permeability conglomerate reservoirs are characterized by strong heterogeneity,small pore throat radius,and complex mineral components.In water injection development of the reservoirs,the content and particle size of suspended solids in reinjection water are main factors leading to reservoir damage.However,the recommended indicators of injection water quality for low-permeability clastic reservoirs are unsuitable for conglomerate reservoirs.Therefore,injection water quality indicators for low-permeability conglomerate reservoirs should be formulated based on the characteristics of the reservoirs.According to the pore structure and clay mineral properties of low-permeability conglomerate reservoirs,this paper employed CT scanning,scanning electron microscopy,and X-ray diffraction to analyze the main factors causing potential damage in water injection from a multitude of perspectives.Additionally,according to the particle plugging theory,suspended solids(SS)in injection water will block the pore throat channel during the injection,resulting in a decrease in permeability and serious damage to low-permeability conglomerate cores.The experimental results show that there are large differences in the damage incurred by concentrations and median particle sizes of SS to the conglomerate cores.To achieve the goal of damage to the target reservoir less than 20%,SS concentration have to be≤1.43 mg/L and median particle size≤1.9μm in the reservoir when the permeability is≤9.28 mD;SS concentration≤3.1 mg/L and median particle size≤2.6μm in the reservoir when the permeability is in the range of 9.28-46.9 mD;SS concentration≤5.1 mg/L and median particle size≤4.8μm in the reservoir when the permeability is≥117 mD.

关 键 词：砾岩低渗透油藏 固体悬浮物 注入水堵塞 粒径 储层伤害 

分 类 号：TE348[石油与天然气工程—油气田开发工程]