Dynamic threshold pressure gradient in tight gas reservoir and its influence on well productivity

2018 ◽  
Vol 11 (24) ◽  
Author(s):  
Jingchen Ding ◽  
Shenglai Yang ◽  
Tongsheng Cao ◽  
Jianbiao Wu
Keyword(s):  
Pressure Gradient ◽  
Dynamic Threshold ◽  
Threshold Pressure ◽  
Tight Gas ◽  
Gas Reservoir ◽  
Threshold Pressure Gradient ◽  
Well Productivity ◽  
Tight Gas Reservoir

Dynamic threshold pressure gradient in tight gas reservoir

2014 ◽  
Vol 20 ◽  
pp. 155-160 ◽  
Author(s):  
Jingchen Ding ◽  
Shenglai Yang ◽  
Xiangrong Nie ◽  
Zhilin Wang
Keyword(s):  
Pressure Gradient ◽  
Dynamic Threshold ◽  
Threshold Pressure ◽  
Tight Gas ◽  
Gas Reservoir ◽  
Threshold Pressure Gradient ◽  
Tight Gas Reservoir

scholarly journals Mathematical Simulation about Gas Transport in a Dual-Porosity Tight Gas Reservoir considering Multiple Effects

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Jing Chen ◽  
Xinmin Song ◽  
Baozhu Li ◽  
Wuguang Li ◽  
Changlin Liao ◽  
...  
Keyword(s):  
Pressure Gradient ◽  
Stress Sensitivity ◽  
Gas Production ◽  
Dual Porosity ◽  
Threshold Pressure ◽  
Tight Gas ◽  
Gas Reservoir ◽  
Threshold Pressure Gradient ◽  
Gas Slippage ◽  
Tight Gas Reservoir

Threshold pressure gradient, gas slippage, and stress sensitivity have important effects on the production of a tight gas reservoir. But previous studies only focused on one or two of these effects. In this study, a mathematical model considering these three effects was established to describe gas transport in a dual-porosity tight gas reservoir. Threshold pressure gradient, gas slippage, and stress sensitivity are simultaneously considered in the velocity term of continuity equation which is mainly different from the previous research results. The partial differential equation and definite solution condition are discretized by a central difference method. A finite difference procedure was compiled and applied to solve this numerical model and predict the productivity of a production well in a dual-porosity tight gas reservoir. The difference between the predicted and tested cumulative production is less than 10%, which indicates that the proposed mathematical model can be used to describe the characteristics of gas flow in the dual-porosity tight gas reservoir. Then, gas productivity of five different scenarios considering these effects was compared. Results show that both stress sensitivity and threshold pressure gradient are negatively correlated with gas production, while gas slippage is positively correlated with gas production. Among them, stress sensitivity has the greatest impact on the production of a dual-porosity tight gas reservoir. Overall, these three effects have great influence on the development of the dual-porosity tight gas reservoir, which should be considered in the production prediction.

Study on the Unstable Seepage Flow Model and the Productivity Characteristics in Tight Gas Heterogeneity Reservoir

2013 ◽  
Vol 868 ◽  
pp. 465-472
Author(s):  
Jia Deng ◽  
Wei Yao Zhu ◽  
Qian Ma ◽  
Huai Jian Yi
Keyword(s):  
Pressure Gradient ◽  
Gas Flow ◽  
Flow Model ◽  
Seepage Flow ◽  
Threshold Pressure ◽  
Tight Gas ◽  
Low Velocity ◽  
Threshold Pressure Gradient ◽  
Tight Gas Reservoir ◽  
Matlab Programming

In this paper, considering on the real threshold pressure gradient (TPG), the mathematical model for low velocity non-Darcy unstable gas flow was established for the tight gas reservoir. Based on the low velocity non-Darcy unstable gas flow model, the gas flow model in heterogeneity formation was developed, and the analytical solution was obtained on the condition of constant production for inner boundary. Then we calculated the model numerically by Matlab programming. Its analyzed that the pressure distribution and the influencing factors such as production rate, producing time, reservoir thickness and the threshold pressure gradient. We compared the heterogeneity formation with the homogeneous formation by the heterogeneity low velocity non-Darcy unstable gas flow model, which shows great difference and illustrate the significance of research on heterogeneity.

scholarly journals Investigation of productivity decline in inter-salt argillaceous dolomite reservoir due to formation damage and threshold pressure gradient: Laboratory, mathematical modeling and application

2016 ◽  
Vol 35 (1) ◽  
pp. 33-53 ◽  
Author(s):  
Dan Wu ◽  
Binshan Ju ◽  
Shiqiang Wu ◽  
Eric Thompson Brantson ◽  
Yingkun Fu ◽  
...  
Keyword(s):  
Pressure Gradient ◽  
Effective Stress ◽  
Stress Sensitivity ◽  
Microscopic Model ◽  
Oil Well ◽  
Threshold Pressure ◽  
Threshold Pressure Gradient ◽  
Well Productivity ◽  
Sensitivity Experiments ◽  
The Impact

The inter-salt argillaceous dolomite reservoirs in the central region of China contain large abundance of oil resources with ultra-low permeability and porosity. However, the oil wells in this area show a very quick reduction with the decline of formation pressure. This article aims to investigate the main possible reasons that affect oil well productivity in the target oilfield. This study begins with analysis of capillary microscopic model, core stress sensitivity experiments, and non-Darcy percolation experiments. The impact of effective stress on permeability and porosity of the reservoir was revealed in this article. The novel productivity model and productivity evaluation model which couples stress sensitivity and threshold pressure gradient were proposed. The analysis of capillary microscopic model shows stress sensitivity of permeability to be much greater than that of porosity during the process of depressurization. The core stress sensitivity experiments results indicate that permeability and effective stress show index relationship while porosity and effective stress show binomial relationship. Damage rate and recovery rate of permeability and porosity were put forward to describe the degree of influence of stress sensitivity on permeability and porosity. The models were used to investigate the factors that affect single well productivity for the target oilfield. Application of the proposed model to this tight oilfield indicates that, the degree of influence of stress sensitivity is much greater than that of threshold pressure gradient. In addition, the greater the stress sensitivity coefficient and threshold pressure gradient are, the greater the productivity reduction will be.

scholarly journals Pressure Performance of Highly Deviated Well in Low Permeability Carbonate Gas Reservoir Using a Composite Model

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5952
Author(s):  
Qinwen Zhang ◽  
Liehui Zhang ◽  
Qiguo Liu ◽  
Youshi Jiang
Keyword(s):  
Pressure Gradient ◽  
Stress Sensitivity ◽  
Composite Model ◽  
Darcy Flow ◽  
Low Permeability ◽  
Threshold Pressure ◽  
Gas Reservoir ◽  
Threshold Pressure Gradient ◽  
Effects Of Stress ◽  
Deviated Wells

It is commonly believed that matrix and natural fractures randomly distribute in carbonate gas reservoirs. In order to increase the effective connected area to the storage space as much as possible, highly deviated wells are widely used for development. Although there have been some studies on the composite model for highly deviated wells, they have not considered the effects of stress sensitivity and threshold pressure gradient in a dual-porosity gas reservoir. In this paper, a semi-analytical composite model for low permeability carbonate gas reservoir was established to study the effect of non-Darcy flow. By employing source function, Fourier transform and the perturbation method, the pressure performance and typical well test curves were obtained. Eight flow regimes were identified, and their characteristics were discussed. As a result, it can be concluded that the effects of stress sensitivity and threshold pressure gradient would make pseudo-pressure and derivative curves rise, which is the characteristic of non-Darcy flow to determine whether there is stress sensitivity or threshold pressure gradient.

Sign in / Sign up

Export Citation Format

Share Document