川中地区保护裂缝性致密砂岩储层屏蔽暂堵技术室内研究  

Study of Shielding Temporary Plugging Technology for the Fractured Sandstone Reservoir Protection in the Center of Sichuan Basin

作　　者：杨建[1] 康毅力[1] 兰林 胡永东[2] 陈家明[2] 

机构地区：[1]"油气藏地质及开发工程"国家重点实验室.西南石油大学 [2]西南油气田川中油气矿

出　　处：《钻井液与完井液》2006年第4期25-27,87-88,共5页Drilling Fluid & Completion Fluid

基　　金：四川省青年科技基金项目(编号:02ZQ026-042)资助

摘　　要：川中地区上三叠系致密砂岩气藏,粘土矿物含量高达15%,平均孔隙度为4.2%,平均渗透率为0.05×10-3μm2,其中50%的喉道半径在0.25μm以下,微裂缝一定程度发育,漏失严重,钻井液的侵入往往对储层造成不可挽救的永久损害,致使气藏开发效率极低。通过对气藏地质特征的深刻认识以及对原钻井液进行粒度分析、暂堵效果评价,提出原工作液粒径主要分布在60~110μm之间,粗颗粒含量已能达到屏蔽暂堵的要求,但是细颗粒和堵裂缝的纤维状粒子不够,因此形成的屏蔽环致密程度不够、渗透率高。对原钻井液进行了改性,加入了适当的架桥粒子、填充粒子以及变形粒子。评价实验结果表明,改性钻井完井液的自然返排恢复率可达89.02%,形成的屏蔽环能承受15 MPa以上的返排压差,因此能有效保护好储层。指出,采取对原钻井液改性来使其达到保护储层的要求的方法,可有效节约作业成本。The tight sandstone gas reservoir of the upper Triassic was in the center of Sichuan basin,the clay mineral content reached as high as 15.3%,the average porosity was 4.2%,and the average permeability was 0.05×10^(-3)μm^2,50% throat radius below 0.25 μm.Micro fractures grew in this gas reservoir,and the working fluid droped out seriously during drilling process,the working fluid invasion usually caused the permanent harm which cannot be saved to this reservoir,this maybe the reason why the gas reservoir deve...

关 键 词：致密砂岩气藏 裂缝性储层 防止地层损害 临时性封堵 钻井液配方 

分 类 号：TE258[石油与天然气工程—油气井工程]