摘要
我国页岩气资源量丰富,与美国页岩气资源量相当。压裂改造形成复杂裂缝是页岩储层获得工业油气流的关键。针对页岩的非均质性特征,页岩水平井均匀改造技术主要通过封堵已改造区域,进一步改造未压裂区域,实现改造段全覆盖,增加裂缝接触面积,提高裂缝复杂程度与作业时效的改造技术。结合组合粒径暂堵球、暂堵球+暂堵剂、暂堵颗粒+暂堵粉末等多种技术手段,优化相关关键参数,形成了3种不同的页岩储层均匀改造工艺模式:段内均匀改造工艺模式、多段均匀改造工艺模式、加密射孔均匀改造工艺模式。暂堵剂较暂堵球到位响应弱,封堵效果显著,泵送排量与封堵效果无直接关系。暂堵压力响应值最高达9 MPa。压裂施工曲线与微地震监测显示,井段均匀改造效果明显,高/低应力区域得到有效改造,监测事件响应点覆盖率100%,单段SRV体积提高40.2%~44.8%,微地震事件数量增长30.4%~53.6%。
In China,there is abundant shale-gas resources equivalent to those in USA.Complex fracturing-induced fractures are crucial to obtain commercial oil and gas flow from shale reservoirs.Due to reservoir heterogeneity,some technologies to plug stimulated segments and stimulate unfractured segments may realize full coverage of stimulated segments,enhance contact area among fractures,and increase fracture complexity and fracturing efficiency.So,with the combination of temporary plugging ball with different size,temporary plugging ball+temporary plugging agent,and temporary particles+temporary plugging powder,some corresponding key parameters were optimized,and three stimulation modes were established,including intra-segment,multi-segment,and uniform stimulation with closely spaced perforation.Compared with temporary plugging ball,temporary plugging agent is weaker in terms of position response,and has more remarkable plugging effect;there is no relationship between pumping displacement and effect;its maximum pressure response may achieve 9 MPa.Moreover,it is shown from fracturing curves and microseismic monitoring that,uniform stimulation may gain an obvious effect,especially in some zones with high or low stress;coverage rate is 100%for those monitoring event response points;and SRV per segment and microseis events increase by 40.2%～44.8%and 30.4%～53.6%,respectively.
作者
曾凌翔
Zeng Lingxiang(Downhole Operation Company,CNPC Chuanqing Drilling Engineering Company Limited,Chengdu,Sichuan 610051,China)
出处
《天然气勘探与开发》
2018年第3期95-101,共7页
Natural Gas Exploration and Development
关键词
页岩气
水平井
均匀改造
暂堵工艺
Shale gas
Horizontal well
Uniform stimulation
Temporary plugging
Technology
