非线性渗流低渗气藏压裂井的产能方程
Analysis on Productivity Equation of Fractured Well in Low Permeability Gas Reservoir with Non-Linear Seepage
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- 引用格式:
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熊健,于路均,郭平.非线性渗流低渗气藏压裂井的产能方程[J].天然气与石油,2012,30(6):0.doi:
.Analysis on Productivity Equation of Fractured Well in Low Permeability Gas Reservoir with Non-Linear Seepage[J].Natural Gas and Oil,2012,30(6):0.doi:
- DOI:
- 作者:
- 熊 健1 于路均2 郭 平1
- 作者单位:
- 1.西南石油大学“油气藏地质及开发工程”国家重点实验室,2.新疆油田公司采气一厂
- 关键词:
- 低渗气藏;椭圆流;压力梯度;滑脱效应;应力敏感;垂直裂缝井;产能方程
Low permeability gas reservoir; Elliptical flow; Pressure gradient; Slippage effect; Stress sensitivity; Vertical fracture well; Productivity equation
- 摘要:
- 大量研究表明,气体渗流特征受到启动压力梯度、滑脱效应、应力敏感等因素影响,针对低渗气藏特征,基于椭圆流模型,根据稳态流理论,引入新的拟压力形式,推导建立了低渗气藏有限导流能力垂直裂缝井产能预测方程。结果表明:启动压力梯度和应力敏感使气井产能下降,随着启动压力梯度和应力敏感系数增大,气井产能不断降低,而滑脱效应使气井产能增大,随着滑脱因子增大,气井产能不断增加;低渗气藏压裂设计中,增加裂缝长度比增加裂缝导流能力更重要,且一定裂缝长度下,存在一个最佳的裂缝导流能力。通过实例计算说明推导的产能预测方程具有可靠性。
A lot of research shows that gas seepage characteristics may be affected by start-up pressure gradient, slippage effect and stress sensitivity. In view of characteristics of low permeability gas reservoir, based on elliptical flow mode and steady seepage theory, introduced is a new quasi pressure form and established is a productivity prediction equation for the finite conductivity vertical fracture well in low permeability gas reservoir and prediction results show that start-up pressure gradient and stress sensitivity may affect gas well production capacity, the capacity will continuously drop along with increase of start-up pressure gradient and stress sensitivity coefficient. However, slippage effect may increase gas well production capacity, the capacity will continuously rise along with increase of slippage coefficient. In low permeability gas reservoir fracturing design, increase of fracture length is more important than increase of fracture flow conductivity and optimal fracture flow conductivity exists in certain fracture length condition. Example calculation results show that above derived productivity prediction equation is reliable.