摘要
页岩气藏低孔超低渗的储层特征决定其只有通过水平井压裂改造才能获得经济产能,而压后产量预测对施工优化设计和经济评估结果都具有重要影响。在总结前人研究的基础上,基于修正后的Warren&Root模型,考虑解吸附、滑脱流动、微裂缝应力敏感等多因素,建立了一个不稳定渗流早期的页岩气产量预测模型,利用拉普拉斯变换和试井方法得到拟压力的解析解,并进行了实例验证与敏感性因素分析。结果表明:该模型计算得出的单井平均日产量与实际值十分接近,证实了该模型的准确性;解吸附和滑脱流动对产量有较大影响,解吸附是页岩气开发过程中重要的产气机制;微裂缝的应力敏感性也会在一定程度上影响产量大小,但影响幅度不及前两个因素。研究结果对页岩气产气机理研究以及早期产量预测具有一定的积极意义。
The property of low porosity and ultra-low permeability of shale gas reservoirs decide that only by the horizontal well fracturing can we obtain the economic productivity, and the forecast of the production after fracture have a great influence on opti.mal plan of treatments and economical estimation. On the basis of summarizing the previous researches, a novel model for produc.tion forecast in the unsteady early period was established based on the corrected Warren ＆ Root model and considered about the desorption, slippage and stress sensitivity of micro fractures. Then the analytical solution for pseudo pressure was obtained by La.place transformation and well-test method. Lastly, the practical production data was used to verify the accuracy of this model, and the factors affecting production were analyzed. The conclusion showed that the computed value and actual value of average daily production for single well in shale gas reservoir were similar to each other, demonstrating the validity of the model. Desorption and slippage had noticeable effects on the production and it also revealed that desorption played an important role in gas output. Howev.er, stress sensitivity could also affect the production in some extent, but the extent of the influence was less than that of desorption and slippage. The conclusions were meaningful for the study of output mechanism of shale gas and early production forecast.
作者
赵金洲
游先勇
李勇明
蒲璇
Zhao Jinzhou;You Xianyong;Li Yongming;Pu Xuan(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu,Sichuan 610500,China)
出处
《油气藏评价与开发》
CSCD
2018年第6期70-76,共7页
Petroleum Reservoir Evaluation and Development
基金
国家自然科学基金重大项目"页岩地层动态随机裂缝控制机理与无水压裂理论"(51490653)
四川省青年科技创新研究团队专项计划项目"页岩气体积压裂排液控制技术研究"(2017TD0013)
关键词
页岩气
不稳定早期
产量预测
解析解
解吸附
shale gas
unsteady period
production forecast
analytical solution
desorption
