Immediate Gas Production from Shale Gas Wells: A Two-Phase Flowback Model

2014 ◽  
Author(s):  
O.A. Adefidipe ◽  
H. Dehghanpour ◽  
C.J. Virues
Keyword(s):  
Shale Gas ◽  
Gas Production ◽  
Gas Wells ◽  
Two Phase

Lithology and sedimentary heterogeneity of the Longmaxi Shale in the southern Sichuan Basin, China

2021 ◽  
pp. 1-49
Author(s):  
Boling Pu ◽  
Dazhong Dong ◽  
Ning Xin-jun ◽  
Shufang Wang ◽  
Yuman Wang ◽  
...  
Keyword(s):  
Continental Shelf ◽  
Deep Water ◽  
Shale Gas ◽  
Sichuan Basin ◽  
Sedimentary Environment ◽  
Gas Production ◽  
Carbonaceous Shale ◽  
Gas Wells ◽  
Longmaxi Shale ◽  
Siliceous Shale

Producers have always been eager to know the reasons for the difference in the production of different shale gas wells. The Southern Sichuan Basin in China is one of the main production zones of Longmaxi shale gas, while the shale gas production is quite different in different shale gas wells. The Longmaxi formation was deposited in a deep water shelf that had poor circulation with the open ocean, and is composed of a variety of facies that are dominated by fine-grained (clay- to silt-size) particles with a varied organic matter distribution, causing heterogeneity of the shale gas concentration. According to the different mother debris and sedimentary environment, we recognized three general sedimentary subfacies and seven lithofacies on the basis of mineralogy, sedimentary texture and structures, biota and the logging response: (1) there are graptolite-rich shale facies, siliceous shale facies, calcareous shale facies, and a small amount of argillaceous limestone facies in the deep - water shelf in the Weiyuan area and graptolite-rich shale facies and carbonaceous shale facies in the Changning area; (2) there are argillaceous shale facies and argillaceous limestone facies in the semi - deep - water continental shelf of the Weiyuan area and silty shale facies in the Changning area; (3) argillaceous shale facies are mainly developed in the shallow muddy continental shelf in the Weiyuan area, while silty shale facies mainly developed in the shallow shelf in the Changning area. Judging from the biostratigraphy of graptolite, the sedimentary environment was different in different stages.

Numerical Simulation Study on the Key Influencing Factors of Water-Invasion Performance for the Gas Wells with Bottom-Water

2014 ◽  
Vol 884-885 ◽  
pp. 104-107
Author(s):  
Zhi Jun Li ◽  
Ji Qiang Li ◽  
Wen De Yan
Keyword(s):  
Numerical Simulation ◽  
Influencing Factors ◽  
Bottom Water ◽  
Simulation Method ◽  
Gas Production ◽  
Production Performance ◽  
Gas Wells ◽  
Two Phase ◽  
Gas Well ◽  
Water Gas

For the water-sweeping gas reservoir, especially when the water-body is active, water invasion can play positive roles in maintaining formation pressure and keeping the gas well production. But when the water-cone break through and towards the well bottom, suffers from the influencing of gas-water two phase flows, permeability of gas phase decrease sharply and will have a serious impact on the production performance of the gas well. Moreover, the time when the water-cone breakthrough will directly affect the final recovery of the gas wells, therefore, the numerical simulation method is used to conduct the research on the key influencing factors of water-invasion performance for the gas wells with bottom-water, which is the basis of the mechanical model for the typical gas wells with bottom-water. It indicate that as followings: (1) the key influencing factors of water-invasion performance for the gas wells with bottom-water are those, such as the open degree of the gas beds, well gas production and the amount of Kv/Kh value; and (2) the barrier will be in charge of great significance on the water-controlling for the bottom water gas wells, and its radius is the key factor to affect water-invasion performance for the bottom water gas wells where the barriers exist nearby.

scholarly journals Iterative Analytical Solutions for Nonlinear Two-Phase Flow with Gas Solubility in Shale Gas Reservoirs

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Xiaoji Shang ◽  
J. G. Wang ◽  
Zhizhen Zhang
Keyword(s):  
Capillary Pressure ◽  
Analytical Solutions ◽  
Shale Gas ◽  
Nonlinear Term ◽  
Two Phase Flow ◽  
Gas Production ◽  
Phase Flow ◽  
Gas Solubility ◽  
Production Rates ◽  
Two Phase

The governing equations of a two-phase flow have a strong nonlinear term due to the interactions between gas and water such as capillary pressure, water saturation, and gas solubility. This nonlinearity is usually ignored or approximated in order to obtain analytical solutions. The impact of such ignorance on the accuracy of solutions has not been clear so far. This study seeks analytical solutions without ignoring this nonlinear term. Firstly, a nonlinear mathematical model is developed for the two-phase flow of gas and water during shale gas production. This model also considers the effects of gas solubility in water. Then, iterative analytical solutions for pore pressures and production rates of gas and water are derived by the combination of travelling wave and variational iteration methods. Thirdly, the convergence and accuracy of the solutions are checked through history matching of two sets of gas production data: a China shale gas reservoir and a horizontal Barnett shale well. Finally, the effects of the nonlinear term, shale gas solubility, and entry capillary pressure on the shale gas production rate are investigated. It is found that these iterative analytical solutions can be convergent within 2-3 iterations. The solutions can well describe the production rates of both gas and water. The nonlinear term can significantly affect the forecast of shale gas production in both the short term and the long term. Entry capillary pressure and shale gas solubility in water can also affect shale gas production rates of shale gas and water. These analytical solutions can be used for the fast calculation of the production rates of both shale gas and water in the two-phase flow stage.

scholarly journals Water-Gas Two-Phase Flow Behavior of Multi-Fractured Horizontal Wells in Shale Gas Reservoirs

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 664 ◽  
Author(s):  
Lei Li ◽  
Guanglong Sheng ◽  
Yuliang Su
Keyword(s):  
Organic Matter ◽  
Shale Gas ◽  
Flow Behavior ◽  
Horizontal Wells ◽  
Gas Production ◽  
Phase Flow ◽  
Gas Reservoirs ◽  
Two Phase ◽  
Fractured Horizontal Wells ◽  
Water Gas

Hydraulic fracturing is a necessary method to develop shale gas reservoirs effectively and economically. However, the flow behavior in multi-porosity fractured reservoirs is difficult to characterize by conventional methods. In this paper, combined with apparent porosity/permeability model of organic matter, inorganic matter and induced fractures, considering the water film in unstimulated reservoir volume (USRV) region water and bulk water in effectively stimulated reservoir volume (ESRV) region, a multi-media water-gas two-phase flow model was established. The finite difference is used to solve the model and the water-gas two-phase flow behavior of multi-fractured horizontal wells is obtained. Mass transfer between different-scale media, the effects of pore pressure on reservoirs and fluid properties at different production stages were considered in this model. The influence of the dynamic reservoir physical parameters on flow behavior and gas production in multi-fractured horizontal wells is studied. The results show that the properties of the total organic content (TOC) and the inherent porosity of the organic matter affect gas production after 40 days. With the gradual increase of production time, the gas production rate decreases rapidly compared with the water production rate, and the gas saturation in the inorganic matter of the ESRV region gradually decreases. The ignorance of stress sensitivity would cause the gas production increase, and the ignorance of organic matter shrinkage decrease the gas production gradually. The water film mainly affects gas production after 100 days, while the bulk water has a greater impact on gas production throughout the whole period. The research provides a new method to accurately describe the two-phase fluid flow behavior in different scale media of fractured shale gas reservoirs.

Numerical study of complex fracture geometry effect on two-phase performance of shale-gas wells using the fast EDFM method

2018 ◽  
Vol 164 ◽  
pp. 603-622 ◽  
Author(s):  
Mohammad AlTwaijri ◽  
Zhaohui Xia ◽  
Wei Yu ◽  
Liangchao Qu ◽  
Yunpeng Hu ◽  
...  
Keyword(s):  
Shale Gas ◽  
Numerical Study ◽  
Gas Wells ◽  
Two Phase ◽  
Fracture Geometry ◽  
Geometry Effect ◽  
Complex Fracture

Analysis of Fractured Sections in Shale Gas Wells Based on PCA - Logistic Regression Model

2020 ◽  
Vol 980 ◽  
pp. 483-492
Author(s):  
Lei Ji ◽  
Ju Hua Li ◽  
Guan Qun Li ◽  
Jia Lin Xiao ◽  
Sean Unrau
Keyword(s):  
Logistic Regression ◽  
Shale Gas ◽  
Logistic Regression Model ◽  
Gas Production ◽  
Gas Wells ◽  
Gas Reservoirs ◽  
Discriminant Model ◽  
Economic Exploitation ◽  
High Production ◽  
Pca Algorithm

In order to optimize the layout and economic exploitation of horizontal fracturing wells and completion in shale gas reservoirs, we propose a model for evaluating shale gas fractured sections based on an improved principle component analysis (PCA) algorithm with logistic regression. The 229 gas production sections in 22 fractured shale gas wells in the main block of the Fuling Shale Development Demonstration Zone were selected, and PCA is used for dimensionalite reduction. According to the PCA results, 6 key parameters are chosen to determine the productivity of fractured wells. Taking the probability distribution of high production after fracturing as the research objective, a logistic regression discriminant model was constructed using the dichotomy method. The prediction results show that the model has 82.1% accuracy and is reliable. The model can be used to classify and gas wells to be fractured, and it provides guiding significance for reasonable optimization of well sections in the area selected for fracturing.

An Innovative Approach to Model Two-Phase Flowback of Shale Gas Wells with Complex Fracture Networks

2016 ◽  
Author(s):  
Ruiyue Yang ◽  
Zhongwei Huang ◽  
Gensheng Li ◽  
Wei Yu ◽  
Kamy Sepehrnoori ◽  
...  
Keyword(s):  
Shale Gas ◽  
Innovative Approach ◽  
Fracture Networks ◽  
Gas Wells ◽  
Two Phase ◽  
Complex Fracture

scholarly journals Prediction and analysis of annular pressure caused by temperature effect for HP/HT/HHS and water production gas wells in Sichuan Basin

2021 ◽  
Author(s):  
Cao Pu
Keyword(s):  
Prediction Model ◽  
Temperature Effect ◽  
Sichuan Basin ◽  
Gas Production ◽  
Influential Factors ◽  
Water Production ◽  
Gas Wells ◽  
Production Rates ◽  
Two Phase ◽  
Actual Measurement

AbstractFor the “three-high” gas wells in Sichuan Basin which are often regulated for production rate and shut-in for maintenance, annular pressure by temperature effect is a kind of wellbore safety threat that cannot be ignored. In this work, the wellbore temperature and pressure calculation model of gas–liquid two-phase flow with non-hydrocarbon correction and the prediction model of annular pressure by temperature effect is developed. Moreover, the judgment chart of annular pressure type is established through a large number of simulation calculations with different gas production rates and water production rates. Example calculation shows that whether water production and non-hydrocarbon components are considered in the prediction model has a non-negligible influence on calculation results. The predicted annular pressure is compared with that obtained from the actual measurement showing a good agreement. Meanwhile, the judgment chart realizes the valid determination of annular pressure type for three “three-high” gas wells in Sichuan Basin. Influential factors analysis indicates that reducing the thermal expansion coefficient of annulus fluid, adding the hollow glass spheres or injecting highly compressible protective liquid into the annulus and installing compressible foam material on the inner wall of casing are effective methods to control the annular pressure by temperature effect. To reserve partial annulus space can effectively reduce the annular pressure by temperature effect. For most of “three-high” gas wells in Sichuan Basin, the optimum height of annulus air cavity is 100 m.

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