摘要
致密油藏由于渗透率低,表现出很强的非线性渗流特征,因此多采用水平井多级压裂技术提高单井产量。基于此,考虑了应力敏感和启动压力梯度的影响,根据物理模型建立裂缝性致密油藏多级压裂水平井试井模型,通过Laplace变换和有限余弦Fourier变换对数学模型进行求解,离散压裂裂缝并结合压降叠加原理,求得有限导流多级压裂水平井井底压力解。将文中的简化模型解与Saphir模型数值解进行对比,验证了简化模型的准确性;根据压力导数曲线特征,将裂缝性致密油藏多级压裂水平井井底压力响应特征曲线分为9个流动阶段,并分析了每个阶段渗流特征及各参数(裂缝分布、窜流系数等)对曲线的影响。该模型可以为裂缝性致密油藏多级压裂水平井试井资料解释和压裂方案设计提供理论依据。
Since the permeability is very low,tight reservoir leads strong non-linear seepage characteristics,and the horizontal well multi-stage fracturing technology is used to improve the single well production.Therefore,according to the physical model,a well test mathematical model of the multistage fractured horizontal well(MFHW)with stress sensitivity and threshold pressure gradient in naturally fractured tight reservoir is established and solved by Laplace transform and finite cosine Fourier transform.The fracture is discretized and the bottom hole pressure solution of the MFHW with finite conductivity is obtained by the pressure drop superposition principle.Compared the simplified model with the numerical solution of the Saphir model,comparison results verify the accuracy of this model.According to the characteristic of pressure derivative curve,the characteristic curve of well bottom pressure response of multi-stage fractured horizontal well in fractured tight reservoir can be divided into nine flow stages.The seepage characteristics of each stage and the influence of parameters(fracture distribution and crossflow coefficient)on the curve are analyzed.The model can provide theoretical basis for well test data interpretation and fracturing design of multi-stage fractured horizontal well in fractured tight reservoir.
作者
何吉祥
徐有杰
高阳
刘启国
HE Jixiang;XU Youjie;GAO Yang;LIU Qiguo(Exploration and Development Research Institute,Xinjiang Oilfield Company,PetroChina,Karamay 834000,China;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu 610500,China)
出处
《断块油气田》
CAS
CSCD
北大核心
2021年第2期241-246,共6页
Fault-Block Oil & Gas Field
基金
国家科技重大专项课题“低渗-致密油藏高效提高采收率新技术”(2017ZX05009-004)
中石油重大专项“陆相中高成熟度页岩油勘探开发关键技术研究与应用”(2019E-2607)。
关键词
多级压裂水平井
有限导流
应力敏感
启动压力梯度
试井
multi-stage fractured horizontal well
finite conductivity
stress sensitivity
threshold pressure gradient
well test
