摘要
页岩气储层渗透率非常低,采用常规压力恢复测试方法评价储层时需要很长时间才能探测到径向流动,导致效率非常低,而微注入压降测试方法可以使页岩气储层在较短时间内出现拟径向流,从而实现储层的快速评价。在分析微注入压降测试方法快速评价页岩气储层原理的基础上,针对涪陵页岩气储层特点,从设备选择、注入排量、总注入量和注入液体选择等方面对微注入压降测试施工参数进行了优化设计。研究结果发现,涪陵页岩气田可以采用150~500L/min排量注入清水进行微注入压降测试,待地层破裂后再持续泵注10~30min,注入总量控制在5~15m3,就可以获得较好的测试结果。采用微注入压降测试方法对涪陵页岩气田6口页岩气井储层进行了评价,通过对压降测试曲线进行G函数分析获得了原始地层压力和储层有效渗透率,其与试验分析和压力测试结果相吻合。这表明,采用微注入压降测试方法可以实现对页岩储层的快速评价。
Shale gas reservoirs are characterized by extremely low permeability. Conventional build-up tests used for reservoir assessments have extremely low efficiencies due to the prolonged time required for detection of radial flows. On the other hand,pre-frac injection/falloff diagnostic test（also known as Diag- nostic Fracture Injection Test,DFIT）can detect pseudo-radial flow in a short time, and consequently may quickly assess reservoir conditions. Based on that, design optimization was performed for shale gas reservoirs in the Fuling Area with consideration to equipment selection, injection flow rates, overall injection volume and properties of injection fluids. Research results showed that satisfactory test results could be ob- tained by using a flow-rate of 150-500L/min and by bumping for 10-30 min after formation fractured. The total volume of injection fluids should be maintained at 5-15 m^3. DFIT had been conducted in 6 wells to as- sess the properties of shale gas reservoirs. Through G-function and ACA analysis using the acquired data, original formation pressures and effective reservoir permeability were determined and it was discovered that relevant results coincided well with formation test results. It had been verified that the DFIT could be used for rapid assessment of shale reservoirs.
出处
《石油钻探技术》
CAS
CSCD
北大核心
2017年第3期107-112,共6页
Petroleum Drilling Techniques
基金
国家自然科学基金重大国际(地区)合作项目"页岩气藏水平井完井与多级压裂增产的基础研究"(编号:51210006)
国家自然科学基金石油化工联合基金(A类)项目"深层高温高压油气井安全高效钻完井基础研究"(编号:U1562212)联合资助
关键词
页岩气
微注入压降测试
试井解释
储层评价
G函数
涪陵页岩气田
shale gas
DFIT
well test data interpretation
reservoir evaluation
G-function
Fuling Shale Gas Field
