高渗砂岩油藏水平井储层保护钻井完井液

塔里木盆地三叠系储层为中孔中–高渗储层，孔隙结构呈强非均质性，潜在固相侵入、微粒运移、出砂、流体敏
感性损害严重，水平井完井投产后自喷、气举困难，甚至没有产量。原井浆粒度分析、动态损害评价实验表明，原井浆
对渗透率100 mD 以上的储层保护能力不佳，返排恢复率低于50%。根据屏蔽暂堵原理对原井浆进行改性，并开展了
改性浆粒度分析及动态损害评价；利用FEI Quanta 450 环境扫描电镜观察了原井浆及改性浆的滤饼结构，借助分形几
何理论分析了滤饼孔隙率、孔径和分形维数等结构参数。结果表明：改性钻井完井液能形成致密的滤饼，有效封堵储
层孔喉，返排恢复率达90% 以上。将改性配方应用到工区水平井钻井现场试验，投产后实现了开井高产自喷。

Drillng and Completion Fluids for High Permeability SandstoneReservoir Protection in Horizontal Well

The Triassic reservoir with medium porosity and medium-high permeability in the Tarim Basin，exhibits intensively
heterogeneous pore structure，and serious potential damage of solid invasion，particle migration，sanding，fluid sensitivity.
After completion，horizontal wells can not produce through natural power or gas-lift. The results of granularity analysis and
dynamic damage evaluation experiments present that the original drilling and completion fluids can not protect the reservoir
with permeability of more than 100 mD，while the percentage of regained permeability is less than 50%. According to the
mechanism of shielding temporary plugging technology，the original drilling and completion fluids are optimized，and the
granularity analysis and dynamic damage evaluation experiments of optimized fluids are carried out. The structure of filter
cakes，both the original and optimized drilling and completion fluids，are observed through the FEI Quanta 450 environment
scanning electron microscope，then the porosity，pore size and fractal dimension of the filter cakes are analyzed with fractal
geometry theory. All results indicated that the optimized drilling and completion fluids can form tight filter cakes，plug the
pore of reservoir effectively，and enhance the percentage of regained permeability of core samples up to 90%. After applying
optimized drilling and completion fluids，horizontal wells achieved production through natural power and got high production
after completion.