低渗透气藏压裂井产能公式推导与分析
Derivation and Analysis on Productivity Formula in Low Permeability Gas Reservoir Fracturing Well Development
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- 引用格式:
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谭,苗,张志全,韩,鑫,陈,菲.低渗透气藏压裂井产能公式推导与分析[J].天然气与石油,2013,31(1):0.doi:
.Derivation and Analysis on Productivity Formula in Low Permeability Gas Reservoir Fracturing Well Development[J].Natural Gas and Oil,2013,31(1):0.doi:
- DOI:
- 作者:
- 谭 苗 张志全 韩 鑫 陈 菲
- 作者单位:
- 长江大学石油工程学院
- 关键词:
- 低渗透气藏；启动压力梯度；滑脱效应；压裂；基质渗透率；气井产能；流入动态；页岩气
Low permeability gas reservoir； Start-up pressure gradient； Slippage effect； Fracturing； Matrix permeability； Gas well productivity； Inflow performance； Shale gas
- 摘要:
- 低渗透气藏一般具有极低的孔隙度和基质渗透率，受滑脱效应和启动压力梯度的影响更为突出。为了更精确地预测低渗透气藏的产能，指导低渗透气藏的合理有效开发，有必要弄清滑脱效应和启动压力梯度对低渗透气井产能的影响大小。针对低渗透气藏特征，基于非达西渗流理论，根据保角交换原理，推导了考虑启动压力梯度、滑脱效应和人工压裂影响的低渗透气井产能方程。分析了不同启动压力梯度和滑脱效应下各流入动态曲线，以及不同的基质渗透率下滑脱效应对气井产能的影响大小。结果表明：随着启动压力梯度的增加，压裂气井产量下降，但下降不明显；随着滑脱系数的增加，压裂气井产量增大；井底流压越低，气井产量随滑脱系数的增加变化越明显；气藏的基质渗透率越低，滑脱效应的变化对气井产能的影响越大。因此，对于特低渗气藏，在低压情况下，滑脱效应的影响不可忽略。
Low permeability gas reservoirs are characterized by low porosity and permeability of matrix， influence of slippage effect and start-up pressure gradient is more outstanding. In order to predict low permeability gas reservoir capacity accurately and develop low permeability gas reservoirs reasonably and effectively， it is necessary to further make clear influence of slippage effect and start-up pressure gradient on low permeability gas well productivity. Analyzed are various inflow dynamic curves under the conditions of different start-up pressure gradients and slippage effects and the influence of slippage effect on gas well productivity under the conditions of different matrix permeability. The results show that fracturing gas well productivity will decrease as start-up pressure gradient increases， but the productivity will decrease significantly and the productivity will increase as slippage effect increases. For very low permeability gas reservoirs， the influence of the slippage effect shall not be neglected in low pressure conditions.
