钻井液与完井液2017，Vol.34Issue(1)：16-22,7.DOI:10.3696/j.issn.1001-5620.2017.01.003
裂缝性气藏封缝堵气技术研究
Plugging Micro-fractures to Prevent Gas-cut in Fractured Gas Reservoir Drilling
摘要
Abstract
The Ordovician carbonate rock reservoirs drilled in Tazhong area (Tarim Basin) have complex geology and developed fractures,50％ of which with widths between 20 μm and 400 μm.These fractures have led to frequent lost circulation,well kick and severe gas cut,which in turn resulted in well control risks.Complex distribution of fractures and high formation temperatures (180 ℃) make bridging with sized particles less effective in controlling mud losses.In laboratory experiment,commonly used testing methods for evaluating the performance of plugging drilling fluids are unable to effectively simulate the real fractures,and hence there is a big discrepancy between the laboratory evaluation and practical performanceof the plugging agents.To solve this problem,a new method has been presented based on the idea of plugging micro-fractures to prevent gas-cut.In this method,natural/artificial cores are used to make test cores with fractures of 20 μm-400 μm in width and roughness that is closely simulating the fractures encountered in the reservoirs drilled.Included in the new method are a device used to evaluate the performance of a drilling fluid in plugging micron fractures,and an evaluation procedure.With this method,particle,fiber and deformable LCMs sized in microns and nanometers were selected and an LCM formulation compatible with polymer sulfonate drilling fluid and ENVIROTHERM NT drilling fluid developed.This plugging PCM formulation,having acid solubility of greater than 70％,does not render contamination to reservoir.关键词
气藏/微裂缝/岩心/封缝堵气/评价方法Key words
Gas reservoir/Micro fracture/Rock core/Plug micro-fracture to prevent gas-cut/Evaluation procedure分类
能源科技引用本文复制引用
韩子轩,林永学,柴龙,李大奇..裂缝性气藏封缝堵气技术研究[J].钻井液与完井液,2017,34(1):16-22,7.基金项目
国家重大专项“彭水地区常压页岩气勘探开发示范工程”(2016ZX05061) （2016ZX05061）
国家自然科学基金重大项目“页岩油气高效开发基础理论研究”(51490650). （51490650）
