由于对气藏直定井温度剖面影响规律认识不清,导致基于分布式光纤温度监测(distributed temperature sensing,DTS)定量评价气藏直定井产出剖面仍十分困难。鉴于此,通过建立考虑多种微量热效应和非等温渗流的多产层气藏直定井温度剖面预...由于对气藏直定井温度剖面影响规律认识不清,导致基于分布式光纤温度监测(distributed temperature sensing,DTS)定量评价气藏直定井产出剖面仍十分困难。鉴于此,通过建立考虑多种微量热效应和非等温渗流的多产层气藏直定井温度剖面预测模型,模拟分析了多个单因素对多产层气藏直定井温度剖面的影响规律,通过正交试验分析,评价出了各单因素对多产层气藏直定井温度剖面的影响程度依次为:渗透率>产量>含水饱和度>井筒倾斜角>天然气相对密度>储层导热系数>井筒半径,确定了影响多产层气藏直定井温度剖面的主导因素为渗透率、产量和含水饱和度。建立的温度剖面预测模型及温度剖面主控因素的确定,为实现基于DTS定量解释气藏直定井产出剖面奠定了理论基础。展开更多
由于缺乏可靠的温度剖面预测模型导致多产层油藏直定井温度剖面影响规律认识不清,使得基于分布式光纤温度监测(distributed temperature sensing,DTS)定量解释多产层油藏直定井产出剖面仍十分困难。鉴于此,通过建立考虑多种微量热效应...由于缺乏可靠的温度剖面预测模型导致多产层油藏直定井温度剖面影响规律认识不清,使得基于分布式光纤温度监测(distributed temperature sensing,DTS)定量解释多产层油藏直定井产出剖面仍十分困难。鉴于此,通过建立考虑多种微量热效应和非等温渗流的多产层油藏直定井温度剖面预测模型,模拟分析了不同单因素变化对多产层油藏直定井温度剖面的影响规律,并通过正交试验分析评价了油藏直定井温度剖面对各影响因素的敏感性程度,依次为:单井产量>渗透率>含水饱和度>井筒直径>原油密度>井筒倾斜角>储层导热系数,确定了影响油藏直定井温度剖面的主导因素为单井产量、渗透率和含水饱和度。研究结果为实现基于DTS数据定量解释多产层油藏直定井产出剖面、储层特征参数等奠定了理论基础。展开更多
It has been known that the productivity of artesian wells is strongly dependent on the rheological properties of crude oils. This work targets two deep artesian wells(>5000 m) that are producing heavy crude oil. Th...It has been known that the productivity of artesian wells is strongly dependent on the rheological properties of crude oils. This work targets two deep artesian wells(>5000 m) that are producing heavy crude oil. The impacts of well conditions including temperature, pressure and shear rate, on the crude oil rheology were comprehensively investigated and correlated using several empirical rheological models. The experimental data indicate that this heavy oil is very sensitive to temperature as result of microstructure change caused by hydrogen bonding. The rheological behavior of the heavy oil is also significantly impacted by the imposed pressure, i.e., the viscosity flow activation energy(Eμ) gently increases with the increasing pressure. The viscosity–shear rate data are well fitted to the power law model at low temperature. However, due to the transition of fluid feature at high temperature(Newtonian fluid), the measured viscosity was found to slightly deviate from the fitting data. Combining the evaluated correlations, the viscosity profile of the heavy crude oil in these two deep artesian wells as a function of well depth was predicted using the oilfield producing data.展开更多
The Jingjiang Reach is experiencing continuous channel degradation owing to operation of the Three Gorges Project （TGP） in 2003. Significant retreat processes at composite riverbanks have occurred at local sites of ...The Jingjiang Reach is experiencing continuous channel degradation owing to operation of the Three Gorges Project （TGP） in 2003. Significant retreat processes at composite riverbanks have occurred at local sites of this reach, which may influence the stability of the fiver regime and the effect of existing river training works. Therefore, bank retreat plays a key role in fluvial processes of the Jingjiang Reach, and it is necessary to predict the long-term processes of bank retreat at typical sections in the reach. In this study, various factors influencing bank retreat in the Jingjiang Reach are investigated, based on bank erosion processes at four sections and the corresponding flow and sediment conditions. It is discovered that fluvial erosion intensity is a dominant factor in controlling the processes of bank retreat in the reach, although other factors, such as bank soil properties, can also influence bank retreat. The bankfull width at a section with severe bank erosion since 2002 is defined as being equal to the sum of the bankfull width in 2002 and the accumulated bank retreat distance after 2002. The magnitude of the bankfull width can be expressed as an exponential function of the previous 5-year average fluvial erosion intensity during flood seasons. The accumulated distances of bank retreat at four sections over the period 2002-2012 are predicted using the proposed empirical relationships, with the calculated bank retreat processes agreeing well with observed data.展开更多
文摘由于对气藏直定井温度剖面影响规律认识不清,导致基于分布式光纤温度监测(distributed temperature sensing,DTS)定量评价气藏直定井产出剖面仍十分困难。鉴于此,通过建立考虑多种微量热效应和非等温渗流的多产层气藏直定井温度剖面预测模型,模拟分析了多个单因素对多产层气藏直定井温度剖面的影响规律,通过正交试验分析,评价出了各单因素对多产层气藏直定井温度剖面的影响程度依次为:渗透率>产量>含水饱和度>井筒倾斜角>天然气相对密度>储层导热系数>井筒半径,确定了影响多产层气藏直定井温度剖面的主导因素为渗透率、产量和含水饱和度。建立的温度剖面预测模型及温度剖面主控因素的确定,为实现基于DTS定量解释气藏直定井产出剖面奠定了理论基础。
文摘由于缺乏可靠的温度剖面预测模型导致多产层油藏直定井温度剖面影响规律认识不清,使得基于分布式光纤温度监测(distributed temperature sensing,DTS)定量解释多产层油藏直定井产出剖面仍十分困难。鉴于此,通过建立考虑多种微量热效应和非等温渗流的多产层油藏直定井温度剖面预测模型,模拟分析了不同单因素变化对多产层油藏直定井温度剖面的影响规律,并通过正交试验分析评价了油藏直定井温度剖面对各影响因素的敏感性程度,依次为:单井产量>渗透率>含水饱和度>井筒直径>原油密度>井筒倾斜角>储层导热系数,确定了影响油藏直定井温度剖面的主导因素为单井产量、渗透率和含水饱和度。研究结果为实现基于DTS数据定量解释多产层油藏直定井产出剖面、储层特征参数等奠定了理论基础。
基金Supported by the National Key Science&Technology Projects during 13th Five-Year Plan(2016ZX05053-003)Young Scholars Development fund of SWPU(201499010121)
文摘It has been known that the productivity of artesian wells is strongly dependent on the rheological properties of crude oils. This work targets two deep artesian wells(>5000 m) that are producing heavy crude oil. The impacts of well conditions including temperature, pressure and shear rate, on the crude oil rheology were comprehensively investigated and correlated using several empirical rheological models. The experimental data indicate that this heavy oil is very sensitive to temperature as result of microstructure change caused by hydrogen bonding. The rheological behavior of the heavy oil is also significantly impacted by the imposed pressure, i.e., the viscosity flow activation energy(Eμ) gently increases with the increasing pressure. The viscosity–shear rate data are well fitted to the power law model at low temperature. However, due to the transition of fluid feature at high temperature(Newtonian fluid), the measured viscosity was found to slightly deviate from the fitting data. Combining the evaluated correlations, the viscosity profile of the heavy crude oil in these two deep artesian wells as a function of well depth was predicted using the oilfield producing data.
基金supported by the CRSRI Open Research Program(Grant No.CKWV2014204/KY)the National Natural Science Foundation of China(Grant Nos.51079103 and 51339001)the National Basic Research Program of China("973" Project)(Grant No.2012CB417001)
文摘The Jingjiang Reach is experiencing continuous channel degradation owing to operation of the Three Gorges Project （TGP） in 2003. Significant retreat processes at composite riverbanks have occurred at local sites of this reach, which may influence the stability of the fiver regime and the effect of existing river training works. Therefore, bank retreat plays a key role in fluvial processes of the Jingjiang Reach, and it is necessary to predict the long-term processes of bank retreat at typical sections in the reach. In this study, various factors influencing bank retreat in the Jingjiang Reach are investigated, based on bank erosion processes at four sections and the corresponding flow and sediment conditions. It is discovered that fluvial erosion intensity is a dominant factor in controlling the processes of bank retreat in the reach, although other factors, such as bank soil properties, can also influence bank retreat. The bankfull width at a section with severe bank erosion since 2002 is defined as being equal to the sum of the bankfull width in 2002 and the accumulated bank retreat distance after 2002. The magnitude of the bankfull width can be expressed as an exponential function of the previous 5-year average fluvial erosion intensity during flood seasons. The accumulated distances of bank retreat at four sections over the period 2002-2012 are predicted using the proposed empirical relationships, with the calculated bank retreat processes agreeing well with observed data.
