scholarly journals Reasonable Pumping Depth for Drainage and Gas Recovery of Shale Gas Wells

2020 ◽  
Vol 38 (3) ◽  
pp. 701-707
Author(s):  
Jianda Chen ◽  
Dajiang Wang ◽  
Zhiquan Zhang ◽  
Jie Liu
Keyword(s):  
Shale Gas ◽  
Design Method ◽  
Technological Parameters ◽  
Gas Wells ◽  
Gas Well ◽  
Gas Recovery ◽  
Wellbore Pressure ◽  
Current Design ◽  
Ultimate Purpose ◽  
Production Characteristics

For shale gas wells, in the initial production stage, the liquid production is large, and the lifting process is needed to assist the drainage. However, for gas wells, especially shale gas wells, the ultimate purpose is different from that of oil wells, and the current design method of pumping depth cannot meet the field requirements. Starting from the production characteristics of liquid-producing gas wells, this paper analyzed the gas well productivity, wellbore pressure distribution and critical liquid-carrying flow, and adopted the node analysis method to propose a design method for the pumping depth of shale gas wells during drainage and gas recovery. Then, the proposed method was applied to optimize the design of the jet pump of well A in Block JY, according to the design results, the pump was started for production; after the wellbore liquid level was raised to the designed depth, the gas well can conduct annulus space liquid-carrying production, and the production effect of well A showed that, the proposed method can be applied as a method for optimizing the technological parameters of shale gas wells.

scholarly journals Shale gas well productivity potential evaluation based on data-driven methods: case study in the WY block

2022 ◽  
Author(s):  
Chaodong Tan ◽  
Hanwen Deng ◽  
Wenrong Song ◽  
Huizhao Niu ◽  
Chunqiu Wang
Keyword(s):  
Shale Gas ◽  
Production Optimization ◽  
Data Driven ◽  
Operating Parameters ◽  
Geological Condition ◽  
Gas Wells ◽  
Gas Well ◽  
Geological Conditions ◽  
Potential Evaluation ◽  
Productivity Potential

AbstractEvaluating the productivity potential of shale gas well before fracturing reformation is imperative due to the complex fracturing mechanism and high operation investment. However, conventional single-factor analysis method has been unable to meet the demand of productivity potential evaluation due to the numerous and intricate influencing factors. In this paper, a data-driven-based approach is proposed based on the data of 282 shale gas wells in WY block. LightGBM is used to conduct feature ranking, K-means is utilized to classify wells and evaluate gas productivity according to geological features and fracturing operating parameters, and production optimization is realized through random forest. The experimental results show that shale gas productivity potential is basically determined by geological condition for the total influence weights of geologic properties take the proportion of 0.64 and that of engineering attributes is 0.36. The difference between each category of well is more obvious when the cluster number of well is four. Meanwhile, those low production wells with good geological conditions but unreasonable fracturing schemes have the greatest optimization space. The model constructed in this paper can classify shale gas wells according to their productivity differences, help providing suggestions for engineers on productivity evaluation and the design of fracturing operating parameters of shale gas well.

scholarly journals Classification and Application of Tight Gas Wells Based on Cluster Analysis

2021 ◽  
Vol 2095 (1) ◽  
pp. 012099
Author(s):  
Zhenhua Cai ◽  
Chuanshuai Zuo ◽  
Jianying Zhu ◽  
Peng Qin ◽  
Baojiang Duan ◽  
...  
Keyword(s):  
Liquid Medium ◽  
High Energy ◽  
Low Energy ◽  
Production Performance ◽  
Tight Gas ◽  
Medium Energy ◽  
Gas Wells ◽  
Gas Field ◽  
Gas Well ◽  
Production Characteristics

Abstract The tight gas field is greatly affected by pressure in the development process. Due to the different production time and formation pressure of each well in the gas field, the production characteristics of the gas well are obviously different. After the gas well sees water, it is impossible to formulate production measures efficiently and accurately. Therefore, by analyzing the production performance characteristics of gas wells, this paper carries out the classification research of tight gas wells, and formulates the corresponding production measures according to the classification results. Taking gas well energy and liquid production intensity as the reference standard of gas well classification, the dynamic parameter indexes characterizing gas well energy and liquid production intensity are established. Gas wells with different production characteristics are divided into six categories by clustering algorithm: high energy-low liquid, high energy-high liquid, medium energy-low liquid, medium energy high-liquid, low energy-low liquid, low energy-high liquid. Then the classification method of tight gas well is formed. In this paper, 50 wells in Linxing block are selected as the research object. The research results show that most of the wells in Linxing block are located in area V, belonging to low energy and low liquid wells. It is recommended to implement intermittent production. The classification based on gas well energy and liquid production intensity are of guiding significance for the formulation of production measures in the Linxing block.

scholarly journals Study on the optimal design of volume fracturing for shale gas based on evaluating the fracturing effect—A case study on the Zhao Tong shale gas demonstration zone in Sichuan, China

2021 ◽  
Vol 11 (4) ◽  
pp. 1705-1714
Author(s):  
Yongxue Lin ◽  
Shanyong Liu ◽  
Shuyang Gao ◽  
Yuan Yuan ◽  
Jia Wang ◽  
...  
Keyword(s):  
Optimal Design ◽  
Shale Gas ◽  
Optimization Design ◽  
Design Method ◽  
Microseismic Monitoring ◽  
Liquid Volume ◽  
Hydraulic Fractures ◽  
Optimized Design ◽  
Gas Wells ◽  
Volume Fracturing

AbstractHydraulic fracturing is the key technology in the development of shale gas reservoirs, and it mainly adopts volume fracturing technology to communicate hydraulic fractures with natural fractures to increase the drainage area. In view of the difficulty in characterizing the complex fractures created by multistaged fracturing in horizontal shale gas wells and the immaturity of fracturing optimization design methods, this study first evaluated the stimulation effect of fracturing technology based on treatment data and microseismic data. Then, the fracture characteristics after frac were considered, and a post-frac simulation was studied based on the discrete fracture network (DFN) model and the microseismic monitoring data as constraints. Finally, from the simulation results, an optimal design method of volume fracturing for shale gas was proposed based on the evaluation of the frac effects. The National Shale Gas Demonstration Zone in Zhaotong, Sichuan Basin was used as an example to study the optimal frac design of shale gas wells. The results show that (1) after optimizing the design, the optimal interval range is 50–70 m, the liquid volume of a single stage is 1800–2200 m3, the amount of sand is 80 m~120 t, and the slurry rate is 10–12 m3/min. (2) Two different frac design schemes were implemented in two wells on the same platform, and the production of the optimized design scheme was 14.7% greater than the original scheme. Therefore, the frac optimization design based on evaluating the fracturing effect can better guide the development of subsequent shale gas wells in this area.

scholarly journals Methane in groundwater before, during, and after hydraulic fracturing of the Marcellus Shale

2018 ◽  
Vol 115 (27) ◽  
pp. 6970-6975 ◽  
Author(s):  
E. Barth-Naftilan ◽  
J. Sohng ◽  
J. E. Saiers
Keyword(s):  
Groundwater Quality ◽  
Shale Gas ◽  
Marcellus Shale ◽  
Gas Wells ◽  
Local Flow ◽  
Gas Well ◽  
Monitoring Wells ◽  
Regional Flow ◽  
Flow Systems ◽  
Methane Concentrations

Concern persists over the potential for unconventional oil and gas development to contaminate groundwater with methane and other chemicals. These concerns motivated our 2-year prospective study of groundwater quality within the Marcellus Shale. We installed eight multilevel monitoring wells within bedrock aquifers of a 25-km2 area targeted for shale gas development (SGD). Twenty-four isolated intervals within these wells were sampled monthly over 2 years and groundwater pressures were recorded before, during, and after seven shale gas wells were drilled, hydraulically fractured, and placed into production. Perturbations in groundwater pressures were detected at hilltop monitoring wells during drilling of nearby gas wells and during a gas well casing breach. In both instances, pressure changes were ephemeral (<24 hours) and no lasting impact on groundwater quality was observed. Overall, methane concentrations ([CH4]) ranged from detection limit to 70 mg/L, increased with aquifer depth, and, at several sites, exhibited considerable temporal variability. Methane concentrations in valley monitoring wells located above gas well laterals increased in conjunction with SGD, but CH4 isotopic composition and hydrocarbon composition (CH4/C2H6) are inconsistent with Marcellus origins for this gas. Further, salinity increased concurrently with [CH4], which rules out contamination by gas phase migration of fugitive methane from structurally compromised gas wells. Collectively, our observations suggest that SGD was an unlikely source of methane in our valley wells, and that naturally occurring methane in valley settings, where regional flow systems interact with local flow systems, is more variable in concentration and composition both temporally and spatially than previously understood.

Application of Ejector Technology to the Efficient Exploitation in the Low-Pressure Gas Well

2013 ◽  
Vol 433-435 ◽  
pp. 2196-2202
Author(s):  
Xue Yuan Long ◽  
Zhi Jun Li ◽  
Yuan Tian
Keyword(s):  
Numerical Simulation ◽  
Design Method ◽  
Field Tests ◽  
Low Pressure ◽  
Structure Design ◽  
Building Structure ◽  
Gas Wells ◽  
Gas Well ◽  
The Cost ◽  
Dynamics Method

According to the research status of spray and drainage technology at home and abroad, based on the basic design of the ejector, this paper designs the ejector geometry, and do numerical simulation and analysis for ejection and combination flow field inside the ejector by using computational fluid dynamics method, building structure design of ejectors with pressure-gain for low-pressure gas wells. Verified by numerical simulation and field tests, the results showed that ejector design method is reliable. The operation of the device at the scene is safe and stable, achieving such goals as using energy from high-pressure wells to drive the low-pressure wells to work stably; delaying pressurization and exploitation for gas wells, reducing the cost of production and management. Field experiment is very effective, providing a new channel for us to increase the pressure of low-pressure gas wells and exploit them.

New Prospect Model for Liquid Loading in Gas Well Base on Energy Balance Theory

2014 ◽  
Vol 711 ◽  
pp. 117-120
Author(s):  
Xu Zhang ◽  
Wei Hua Liu ◽  
Tao Zhang
Keyword(s):  
Real Time ◽  
New Method ◽  
Gas Wells ◽  
Liquid Loading ◽  
Gas Well ◽  
Gas Recovery ◽  
Flow Situation ◽  
Actual Flow ◽  
Normal Production ◽  
Water Cut

Accurate and timely recognizing whether gas wells get effusion is one of the important guarantee to ensure the normal production of water-cut gas well. It often gets errors when using current normal recognizing methods of the critical carrying fluid flow model to predict and recognize the actual flow situation in these wellbores, which already have effusion or have been drained effusion by taking measures. This paper is based on the coordinating relation between the energy of gas well itself and the energy required for draining effusion out, establishing a new method to recognize gas well effusion, and establishing a relatively complete system of gas well effusion identification. Combined with field production data, this method can be more accurately used to recognize gas effusion and real-time trace, and it can avoid the above problems. Combined with the instance of gas well for real-time effusion diagnosis, the predicted result is very good agreement with actual situation. This new method has important guiding significance for the normal production of water producing gas wells and the implementation of related gas recovery with water draining.

scholarly journals Examples of discriminating the downward depth and downward timing of the velocity string in the water-producing gas well

2021 ◽  
Vol 248 ◽  
pp. 01072
Author(s):  
Jing Yang ◽  
Minhao Guo ◽  
Yan Le ◽  
Xin Fan ◽  
Haiyang Wang ◽  
...  
Keyword(s):  
Carrying Capacity ◽  
Ordos Basin ◽  
Technical Problem ◽  
Recovery Process ◽  
Formation Pressure ◽  
Gas Wells ◽  
Gas Well ◽  
Wellhead Pressure ◽  
Gas Recovery ◽  
Bottom Hole

The problem of bottom hole effusion is an important reason for the reduction and even shutdown of natural gas wells. Downward velocity string is an important drainage gas recovery process, which can improve the flow rate of gas and discharge more liquid from the wellhead. However, the depth and timing of the velocity string is a technical problem that has been difficult to solve by field engineers. To solve this problem, this paper designs a method to select the depth and timing of the velocity string in the case of highly deviated wells and applies this method to Well X6–2 and Well X2–1 of PCOC in Ordos Basin, China. The optimization results show that when the wellhead pressure is 6.26 MPa, Well X6–2 should lower the 2–1.71 in. or 2.375–1.995 in. velocity string to 3337.9 m before the formation pressure decays to 8.800 MPa, which is most conducive to improve the liquid carrying capacity of gas wells. When the wellhead pressure is 4 MPa, Well X2–1 should lower 2–1.71in. velocity string to 3401.3 m before the formation pressure decays to 5.800 MPa, or lower 2.375–1.995 in. velocity string to 3401.3 m before the formation pressure decays to 5.900 MPa.

Pressure-Dependent Natural-Fracture Permeability in Shale and Its Effect on Shale-Gas Well Production

2013 ◽  
Vol 16 (02) ◽  
pp. 216-228 ◽  
Author(s):  
Y.. Cho ◽  
O.G.. G. Apaydin ◽  
E.. Ozkan
Keyword(s):  
Shale Gas ◽  
Flow Model ◽  
Natural Fracture ◽  
Fracture Permeability ◽  
Gas Wells ◽  
Gas Well ◽  
Fracture Conductivity ◽  
Pressure Drops ◽  
Well Production ◽  
The Matrix

Summary This paper presents an investigation of the effect of pressure-dependent natural-fracture permeability on production from shale-gas wells. The motivation of the study is to provide data for the discussion of whether it is crucial to pump proppant into natural fractures in shale plays. Experiments have been conducted on Bakken-shale core samples to select appropriate correlations to represent fracture conductivity as a function of pressure (the actual characterization of fracture conductivity under stress for a specific formation is not an objective of the study). Correlations have been used in a flow model to demonstrate the potential impact of natural-fracture closure as pressure drops during production. Although the correlations indicate up to an 80% reduction in fracture permeability over practical ranges of pressure, the results of the flow model do not warrant the claims that fracture closing plays a significant role in the productivity losses of shale-gas wells. A history match of the performances of two wells in the Barnett and Haynesville formations also indicates that the effect of pressure-dependent natural-fracture permeability on shale-gas-well production is a function of the permeability of the matrix system. If the matrix system is too tight, then the retained permeability of the natural fractures may still be sufficient for the available volume of the fluid when the system pressure drops.

scholarly journals A Production Prediction Method for Shale Gas Wells Based on Multiple Regression

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1461
Author(s):  
Wente Niu ◽  
Jialiang Lu ◽  
Yuping Sun
Keyword(s):  
Prediction Model ◽  
Multiple Regression ◽  
Shale Gas ◽  
Evaluation Method ◽  
Pearson Correlation ◽  
Controlling Factors ◽  
Accurate Prediction ◽  
Gas Wells ◽  
Gas Well ◽  
Training Samples

The estimated ultimate recovery (EUR) of a single shale gas well is one of the important evaluation indicators for the scale and benefit development of shale gas, which is affected by many factors such as geological and engineering, so its accurate prediction is difficult. In order to realize the accurate prediction of ultimate recovery, this study considered 172 shale gas wells in the Weiyuan block as samples and selected 19 geological and engineering factors that affect the ultimate recovery of shale gas wells. Furthermore, eight key controlling factors were selected by means of the Pearson correlation coefficient and maximum mutual information coefficient comprehensive evaluation method. The data were divided into training and testing samples. Different numbers of training samples were selected and seven schemes were designed. Based on the key controlling factors, the ultimate recovery prediction model for shale gas wells in this block was established through multiple regression methods. The effectiveness of the prediction model was verified by analyzing the testing samples. The result shows that with the increase of the size of training samples, the error of the ultimate recovery predicted by the model gradually decreases gradually. When predicting the single gas well, the average absolute error of ultimate recovery is less than 20% if the number of the training gas well is more than 80. When analyzing the development potential of similar blocks without drilling, the error of the sum of ultimate recovery is less than 10% if the size of the training gas well reaches 60.

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