Comprehensive Analysis of Production Loggings in Fuling Shale Gas Play in China

2021 ◽  
Author(s):  
Yaowen Liu ◽  
Wei Pang ◽  
Jincai Shen ◽  
Ying Mi
Keyword(s):  
Shale Gas ◽  
Mineral Content ◽  
Horizontal Wells ◽  
Organic Content ◽  
Gas Production ◽  
Liquid Loading ◽  
Comprehensive Overview ◽  
Gas Field ◽  
Well Trajectory ◽  
Positive Effect

Abstract Fuling shale gas field is one of the most successful shale gas play in China. Production logging is one of the vital technologies to evaluate the shale gas contribution in different stages and different clusters. Production logging has been conducted in over 40 wells and most of the operations are successful and good results have been observed. Some previous studies have unveiled one or several wells production logging results in Fuling shale gas play. But production logging results show huge difference between different wells. In order to get better understanding of the results, a comprehensive overview is carried out. The effect of lithology layers, TOC (total organic content), porosity, brittle mineral content, well trajectory is analyzed. Results show that the production logging result is consistent with the geology understanding, and fractures in the favorable layers make more gas contribution. Rate contribution shows positive correlation with TOC, the higher the TOC, the greater the rate contribution per stage. For wells with higher TOC, the rate contribution difference per stage is relatively smaller, but for wells with lower TOC, it shows huge rate contribution variation, fracture stages with TOC lower than 2% contribute very little, and there exist one or several dominant fractures which contributes most gas rate. Porosity and brittle minerals also show positive effect on rate contribution. The gas rate contribution per fracture stage increases with the increase of porosity and brittle minerals. The gas contribution of the front half lateral and that of latter half lateral are relatively close for the "upward" or horizontal wells. However, for the "downward" wells, the latter half lateral contribute much more gas than the front half lateral. It is believed that the liquid loading in the toe parts reduced the gas contribution in the front half lateral. The overview research is important to get a compressive understanding of production logging and different fractures’ contribution in shale gas production. It is also useful to guide the design of horizontal laterals and fractures scenarios design.

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.

Quantitative analysis of seismic response to total organic content and thermal maturity in shale gas plays

2011 ◽  
Vol 51 (2) ◽  
pp. 704
Author(s):  
Ebrahim Hassan Zadeh ◽  
Reza Rezaee ◽  
Michel Kemper
Keyword(s):  
Seismic Response ◽  
Shale Gas ◽  
Effective Medium Theory ◽  
Rock Physics ◽  
Sedimentary Basins ◽  
Organic Content ◽  
Effective Porosity ◽  
Forward Modelling ◽  
Gas Field ◽  
Simultaneous Inversion

Although shales constitute about 75% of most sedimentary basins, the studies dealing with their seismic response are relatively few, particularly for the organic rich shale gas. Mapping distribution of shale gas and identifying their maturation level and organic carbon richness is critically important for unconventional gas field exploration and development. This study analyses the sensitivity of acoustic and elastic parameters of shales to variations in pore fluid content. Based on the effective medium theory a rock physics model has been made by inversion of the shale stiffness tensor from sonic, density, porosity and clay content logs. Due to the lack of a generally agreed upon fluid substitution model for shale, a statistical approach to Gassmann’s Model using effective porosity in the near boundary conditions, has been developed to account for shale. Fluid substituted logs—for a variety of maturation levels—and gas saturations were generated and used to make the layered earth models. AVO and seismic forward modelling were performed using the rock physics modelled and the fluid substituted logs on layered models. As part of seismic forward modelling, simultaneous inversion is performed for each model to generate P-impedance, S-impedance and density volumes. The sensitivity of the models were analysed by histogram, cross plotting, cross section highlighting, and body checking techniques. This study showed a dramatic hydrocarbon content effect—specifically gas—in the seismic response of shales.

Remote-Controlled Automated Foam Injection: A Digital Solution to Liquid Loading in a China Unconventional Gas Development

2021 ◽  
Author(s):  
Jiang Wei Bo ◽  
Beryl Audrey ◽  
Uzezi Orivri ◽  
Nian Xi Wang ◽  
Xiang Yang Qiao ◽  
...  
Keyword(s):  
Remote Control ◽  
Continuous Production ◽  
Weather Conditions ◽  
Gas Production ◽  
Liquid Loading ◽  
Gas Field ◽  
Field Development ◽  
Operational Risks ◽  
Tight Gas Reservoir ◽  
Unconventional Gas Development

Abstract Gas field C is an unconventional tight gas reservoir located in the central of China which has prominent characteristics, including thin formation, low permeability and poor reservoir connectivity which significantly impact on the field development. Horizontal wells multistage hydraulic fracturing has been proven to be an effective technique to recover the hydrocarbons from this gas field. However, with continuous production overtime, reservoir pressure declines which results in a decrease in gas production rate below the critical gas velocity, leading to accumulation of liquid in the wellbore (liquid loading), which further results in back pressure and damage to the formation. Currently, gas field C loses up to 1500 mmscf/year in gas production and associated revenue due to liquid loading. Some other factors which hinders effective deliquification of the gas wells include remote well pad locations, poor road conditions during harsh weather conditions, friction with local communities, limited manpower to daily effectively analyze over 200 wells for liquid loading diagnostics and operational risks during well intervention. To tackle these challenges, a new versatile intelligent dosing technology has been piloted to reduce liquid loading. This remote-control dosing unit is located at the well pad and is equipped with automatic valves that can dispense two different chemicals (soap and methanol) in one unit. A key new feature of this system is the ability to receive and implement instructions that optimizes the dosing rate and frequency. This remote-control functionality eliminates on-site operator intervention and HSE risks especially in winter when the well pads could be inaccessible with poor road conditions.

scholarly journals General Optimization Model of Modular Equipment Selection and Serialization for Shale Gas Field

2021 ◽  
Vol 9 ◽  
Author(s):  
Bingyuan Hong ◽  
Xiaoping Li ◽  
Xuemeng Cui ◽  
Jingjing Gao ◽  
Yu Li ◽  
...  
Keyword(s):  
Shale Gas ◽  
Optimization Model ◽  
Supply And Demand ◽  
Gas Production ◽  
Equipment Management ◽  
Gas Field ◽  
Actual Case ◽  
Processing Cost ◽  
Green Production ◽  
Productivity Prediction

The potential technical and economic advantages and flexible operability of modular equipment make it increasing widely used in gas field production and development. In addition to considering the manufacturing process, the selection and serialization of modular equipment should be made according to the productivity prediction of a gas well, so as to meet the field demand to the greatest extent and enhance the flexibility of gathering and transportation system. This article proposes a method to determine the use planning of modular equipment in shale gas field. Considering the processing capacity, processing cost, floor area, construction cost of modular equipment, and the changes of market supply and demand, an optimization model is established. On the basis of the abovementioned model, the method of serialization of modular equipment is proposed. The effectiveness of the model is verified by an actual case study. It is proved that the model can optimize the layout of modular equipment, make the modular equipment run efficiently and economically, reduce costs, and increase efficiency. This study provides a reference for optimizing the equipment management strategy and promoting green production practice of shale gas production.

scholarly journals Development Evaluation and Optimization of Deep Shale Gas Reservoir with Horizontal Wells Based on Production Data

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Wuguang Li ◽  
Hong Yue ◽  
Yongpeng Sun ◽  
Yu Guo ◽  
Tianpeng Wu ◽  
...  
Keyword(s):  
Shale Gas ◽  
Production System ◽  
Target Position ◽  
Horizontal Wells ◽  
Gas Production ◽  
Well Performance ◽  
Gas Reservoir ◽  
Horizontal Section ◽  
Technical Problems ◽  
Shale Gas Reservoir

The implementation of horizontal wells is a key to economic development of the deep shale gas reservoir. In order to optimize the key parameters for drilling, stimulation, and the production system, the development effect of a horizontal well in deep shale gas formations was investigated from various aspects in this study. The drilling, fracturing, and production performances of this well were analyzed combining with the geological characteristics. The main technical problems and key factors that restrict the gas well performance and estimated ultimate recovery (EUR) were clarified. Through the integrated study of geology and engineering, the optimization strategies for increasing gas production and EUR are provided. The Z2 area, where the Z2-H1 well is located, has good reservoir physical properties, which bring a high drilling efficiency. However, there are still some problems during its development, such as poor fracture extension both horizontally and vertically, limited stimulated reservoir volume (SRV), rapid production declining, large water production, and serious liquid accumulation. In this study, a comprehensive approach was proposed that can improve single-well production and EUR by optimizing the target position, horizontal section length, pathway, spacing, new drilling and fracturing technology, and production system.

A New Model for Predicting Liquid Loading in Shale Gas Horizontal Wells

2021 ◽  
Author(s):  
Chao Zhou ◽  
Zuqing He ◽  
Yashu Chen ◽  
Zhifa Wang ◽  
Amol Mulunjkar ◽  
...  
Keyword(s):  
Flow Rate ◽  
Shale Gas ◽  
Liquid Flow Rate ◽  
Liquid Droplet ◽  
Case Analysis ◽  
Horizontal Wells ◽  
Critical Flow ◽  
Liquid Loading ◽  
Critical Flow Rate ◽  
New Model

Abstract Current critical flow rate models fail to accurately predict the liquid loading statuses of shale gas horizontal wells. Therefore, a new critical flow rate model for the whole wellbore of shale gas horizontal wells is established. The results of the new model are compared to those of current models through the field case analysis. The new model is based on the dynamic analysis and energy analysis of the deformed liquid-droplet, which takes into account the liquid flow rate, the liquid-droplet deformation and the energy loss caused by the change of buildup rate. The major axis of the maximum stable deformed liquid-droplet is determined based on the energy balance relation. Meanwhile, the suitable drag coefficient equation and surface tension equation applied to shale gas horizontal wells are chosen. Finally, the critical flow rate equation is established and the maximum critical flow rate of the whole wellbore is chosen as the criterion for liquid loading prediction. The precision of liquid loading prediction of the new model is compared to those of the four current models, including Belfroid's model, modified Li's model, liquid film model and modified Wang's model. Field parameters of 29 shale gas horizontal wells are used for the comparison, including parameters of 18 unloaded wells, 2 near loaded-up wells and 9 loaded-up wells. Field case analysis shows that the total precision of liquid loading prediction of the new model is 93.1%, which is higher compared to those of the current four models. The new model can accurately predict the liquid loading statuses of loaded-up wells and near loaded-up wells, while the prediction precision for unloaded wells is high enough for the field application, which is 88.9%. The new model can be used to effectively estimate the field liquid loading statuses of shale gas horizontal wells and choose drainage gas recovery technologies, which considers both the complex wellbore structure and the variation of flowback liquid flow rate in shale gas horizontal wells. The results of the new model fill the gap in existing studies and have a guiding significance for liquid loading prediction in shale gas horizontal wells.

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