scholarly journals A Novel Mathematical Model Considering Real Gas PVT Behavior to Estimate Inflow Performance Relationship of Gas Well Production

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3594
Author(s):  
Shuang Zhang ◽  
Huiqing Liu ◽  
Yanwei Wang ◽  
Ke Sun ◽  
Yunfei Guo

Inflow performance relationship (IPR) is one of the most important methods for the analysis of the dynamic characteristics of gas reservoir production. The objective of this study was to develop a model to improve the accuracy of the IPR for evaluating and predicting the production of gas reservoirs. In this paper, a novel mathematical model, taking into account the real gas PVT behavior, is developed to accurately estimate the inflow performance relationship. By introducing a pseudo-pressure function and a real gas properties database, this model eliminates the error caused by the linearization method and improves the calculation accuracy. The results show that more than 90% of the energy in the flow field is consumed by inertial forces, which leads to significant high-velocity non-Darcy effects in the gas reservoir. The reservoir permeability, original reservoir pressure, stress sensitivity coefficient, and skin factor have a great impact on the inflow performance relationship of gas reservoir production. This model predicts gas IPR curves with excellent accuracy and high efficiency. The high-precision gas well inflow performance relationship lays a solid foundation for dynamic production analysis, rational proration, and intelligent development of the gas field.

2013 ◽  
Vol 868 ◽  
pp. 737-741 ◽  
Author(s):  
Feng Wang ◽  
Ji Nan Zhang ◽  
Chong Xi Li

The phenomenon of hydrate freeze-plugging is very widespread in Jilin oilfield M gas field exploitation. Freeze-plugging tends to occur in winter, mainly including ground pipeline, wellhead and wellbore freeze-plugging, etc, which affects the normal production of gas well, also has restricted the gas reservoir development and will cause huge economic losses. In order to prevent the freeze-plugging occurred in gas well, methyl alcohol is used to inject into single well at the rate of 600 to 3080 L/day. The field condition shows that the result of injecting methanol is not obvious, besides, the toxicity of methanol and its high cost already cannot satisfy the oilfield actual demand. Therefore, we need to research and develop new hydrate inhibitors with low cost and high efficiency to solve the problem of freeze-plugging.


2014 ◽  
Vol 962-965 ◽  
pp. 570-573
Author(s):  
Jian Yan ◽  
Xiao Bing Liang ◽  
Qian Wu ◽  
Qing Guo

Because of the gas slippage, the testing methods of stress sensitivity for gas reservoir should be different from that for oil reservoir. This text adopts the method that imposing back pressure on the outlet of testing core to weaken the gas slippage effect and tests the stress sensitivity of low permeability gas reservoirs, then analyzes the influence of permeability and water saturation on stress sensitivity. The results show that: low permeable and water-bearing gas reservoirs have strong stress sensitivity; the testing permeability has the power function relationship with net stress, compared to the exponential function, the fitting correlation coefficient is larger and more suited to the actual; the lower the permeability is and the higher water saturation is, the stronger the stress sensitivity is. The production of gas well is affected when considering the stress sensitivity, so the pressure dropping rate should be reasonable when low permeable gas reservoirs are developed. The results provide theoretical references for analyzing the well production and numerical simulation.


Author(s):  
Tao Zhu ◽  
Jing Lu

Many gas reservoirs are with bottom water drive. In order to prevent or delay unwanted water into the wellbore, the producing wells are often completed as partially penetrating vertical wells, and more and more horizontal wells have been drilled in recent years in bottom water drive gas reservoirs to reduce water coning and increase productivity. For a well, non-Darcy flow is inherently a near wellbore phenomenon. In spite of the considerable study that non-Darcy behavior of fully penetrating vertical wells, there has been no study of a partially penetrating vertical well or a horizontal well in a gas reservoir with bottom water drive. This paper presents new binomial deliverability equations for partially penetrating vertical gas wells and horizontal gas wells, assuming that only radial flow occurs in the near wellbore non-Darcy’s flow domain. The inflow performance of a vertical gas well is compared with that of a horizontal gas well. The proposed equations can account for the advantages of horizontal gas wells.


2014 ◽  
Vol 1073-1076 ◽  
pp. 592-596
Author(s):  
Pei Luo ◽  
Yu Ming Luo ◽  
Kai Ma ◽  
Biao Zhang ◽  
Sha Sha Song

In the process of high sulfur gas field development, the sulfur will separate out from the mixed gas when the pressure near wellbore area drops to a critical pressure of H2S. This will reduce the reservoir porosity greatly and decrease the gas well productivity as well. This paper discusses the characteristics of pressure transient testing plots when sulfur deposition occurs based on the redial composite reservoir model. And introduce an approach to determine the sulfur deposition radius near the wellbore with pressure transient testing interpretation in high sulfur gas reservoir. The method has been applied in some high sulfur gas field in eastern Sichuan Basin. The result shows that the method is simple and practical.


2020 ◽  
Vol 213 ◽  
pp. 02001
Author(s):  
Quan Hua Huang ◽  
Hong Jun Ding ◽  
Xing Yu Lin

At present, multiphase flow productivity calculation requires many parameters, and most of them only consider oil and gas two-phase flow, which is complicated and limited. Therefore, a reasonable productivity formula of condensate gas reservoir with producing water is needed. The three-zone model of condensate gas reservoirs is generally applied to the physical model for inferring productivity. On this basis, an improved model is established, which includes that different seepage characteristics are considered for different zones. Moreover, the effects of inclined angle and water production on gas wells are regarded as pseudo-skin factors and additional-skin factors. In addition, Zone I considers the effects of high-speed nonDarcy effect(HSND), starting pressure gradient, stress sensitivity, inclined angle and water production; Zone II is the same way excepting starting pressure gradient and stress sensitivity ; Zone III only considers the effects of inclined angle and water production. As a result, a productivity equation with multiple factors for condensate gas wells is established. Through analysing cases and influences in H gas reservoir X1 well, the HSND, starting pressure gradient, stress sensitivity and water production have a negative impact on gas well productivity, but the inclined angle is opposite. Founded that the starting pressure gradient impacts on productivity is less than the HSND because of the limited radius of Zone I; the impact of the HSND on productivity increases with the decreasing of bottom hole pressure; the impact of water production on gas well productivity is much higher. When the angle is over 60°, the effect of gas


2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Xiaoliang Huang ◽  
Xiao Guo ◽  
Xiang Zhou ◽  
Xinqian Lu ◽  
Chen Shen ◽  
...  

The development process of a dipping gas reservoir with an aquifer considering stress sensitivity is complex. With gas development, formation pressure decreases, stress-sensitive effect decreases permeability and porosity, and formation water could flow into the development gas well and gather in the wellbore. The accumulation of water may lead to a lower gas rate. Simultaneously, the gravity action of fluid caused by formation dip angle affects gas well productivity. However, few studies have investigated a deliverability model for a water-producing gas well with a dipping gas reservoir considering stress sensitivity. For this reason, it is important to determine the relationships between gas well productivity and stress sensitivity, formation angle, and water production. In this research, a new mathematical model of deliverability was developed for a water-producing gas well with a dipping gas reservoir considering stress sensitivity. Additionally, a new equation was developed for gas well productivity. By analyzing a typical dipping gas reservoir with an aquifer, the level of influence on gas well productivity was determined for stress sensitivity, formation angle, and water–gas ratio (WGR). The work defined the relationships between gas well productivity and stress sensitivity, formation angle, and WGR. The results indicate that deliverability increases with an increase in formation angle, and growth rate hits its limit at an angle of 40 deg. Due to the influence of formation angle, fluid gravity leads to production pressure differences in gas wells. When bottom-hole flow pressure equaled formation pressure, gas well production was not 0 × 104 m3/d, the angle was large, and gas well production was greater. Deliverability and stress sensitivity hold a linear relationship: the stronger the stress sensitivity, the lower the deliverability of the gas well, with the stress sensitivity index from 0 to 0.06 MPa−1 and the deliverability decrease rate at 37.2%. Deliverability and WGR hold an exponential relationship: when WGR increased from 0.5 to 15.0 m3/104 m3, the deliverability decrease rate was 71.8%. The model and the equations can be used to predict gas deliverability in a dipping gas reservoir with an aquifer considering stress sensitivity. It can also be used to guide the development process for a dipping gas reservoir with an aquifer.


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