Our database tracking of USA water usage per well indicates that traditionally shale operators have been using, on average 3 to 6 million gallons of water; even up to 8 million for the en- tire life cycle of the well ...Our database tracking of USA water usage per well indicates that traditionally shale operators have been using, on average 3 to 6 million gallons of water; even up to 8 million for the en- tire life cycle of the well based on its suitability for re-fracturing to stimulate their long and lateral ho- rizontal welis. According to our data, sourcing, storage, transportation, treatment, and disposal of this large volume of water could account for up to 10% of overall drilling and completion costs. With in- creasingly stringent regulations governing the use of fresh water and growing challenges associated with storage and use of produced and flowback water in hydraulic fracturing, finding alternative sources of fracturing fluid is already a hot debate among both the scientific community and industry experts. On the other hand, waterless fracturing technology providers claim their technology can solve the concerns of water availability for shale development. This study reviews high-level technical issues and opportunities in this challenging and growing market and evaluates key economic drivers behind water management practices such as waterless fracturing technologies, based on a given shale gas play in the United States and experience gained in Canada. Water costs are analyzed under a variety of scenarios with and without the use of （fresh） water. The results are complemented by surveys from several oil and gas operators. Our economic analysis shows that fresh water usage offers the greatest economic return. In regions where water sourcing is a challenge, however, the short-term economic advantage of using non-fresh water-based fracturing outweighs the capital costs required by waterless fracturing methods. Until waterless methods are cost competitive, recycled water usage with low treatment offers a similar net present value （NPV） to that of sourcing freshwater via truck, for in- stance.展开更多
A distributed feedback diode laser （DFB-DL） based hygrometer combined with a long-path-length Herriot gas cell and waterless optical components was proposed and investigated. The main function of this sensor was to ...A distributed feedback diode laser （DFB-DL） based hygrometer combined with a long-path-length Herriot gas cell and waterless optical components was proposed and investigated. The main function of this sensor was to simultaneously improve the measurement reliability and resolution. A comparison test between a 10-cm normal transmission-type gas cell and a 3-m Herriot gas cell was carried out to demonstrate the improvement. Reliability improvement was achieved by influence suppression of water vapor inside optical components （WVOC） through combined action of the Herriot gas cell and waterless optical components. The influence of WVOC was suppressed from 726ppmv to 25ppmv using the Herriot gas cell. Moreover, combined with waterless optical components, the influence of WVOC was further suppressed to no more than 4ppmv. Resolution improvement from l l.7ppmv to 0.32ppmv was achieved mainly due to the application of the long-path-length Herriot gas cell. The results show that the proposed sensor has a good performance and considerable potential application in gas sensing, especially when probed gas possibly permeates into optical components.展开更多
Live fish waterless transportation could be recognized as an essential supplement for water-based transportation due to its low oxygen consumption and less waste water pollution.The critical problem to maintaining the...Live fish waterless transportation could be recognized as an essential supplement for water-based transportation due to its low oxygen consumption and less waste water pollution.The critical problem to maintaining the fish survival quality under such a unique transport strategy is accurately controlling the oxygen concentration in the container to be constantly at stable and high levels.This paper aims to propose an improved fuzzy PID control system based on the grey model with residual rectification by improved particle swarm optimized Gated Recurrent Unit(GM-IPSO-GRU)to realize advanced oxygen level control.In addition,it is also reinforced by adopting the improved grey wolf optimization(IGWO)for the majorization of control parameters(quantization factors,scale factors)with full consideration of fish size features.In this study,Turbot(Scophthalmus maximus)is taken as the test subject to verify the integrated control performance of the optimized fuzzy PID controller through simulated waterless live transportation under lowtemperature conditions.The proposed control system is validated as more efficient than the traditional proportional integral derivative(PID)and fuzzy PID algorithms for handling its nonlinear,time-varying,and time lag problems well.In summary,the control group experiment shows that the newly-designed control system has the advantages of shorter stabilization time,minor overshoot,and strong anti-interference ability for oxygen level adjustment.Finally,applying this novel control technology can effectively improve oxygen adjustment efficiency and provide feasible quality control support for the deep optimization of the live fish circulation industry.展开更多
With the increasing demand for energy,traditional oil resources are facing depletion and insufficient supply.Many countries are rapidly turning to the development of unconventional oil and gas resources.Among them,sha...With the increasing demand for energy,traditional oil resources are facing depletion and insufficient supply.Many countries are rapidly turning to the development of unconventional oil and gas resources.Among them,shale oil and gas reservoirs have become the focus of unconventional oil and gas resources exploration and development.Based on the characteristics of shale oil and gas reservoirs,supercritical CO_(2) fracturing is more conducive to improving oil recovery than other fracturing technologies.In this paper,the mechanism of fracture initiation and propagation of supercritical CO_(2) in shale is analyzed,including viscosity effect,surface tension effect,permeation diffusion effect of supercritical CO_(2),and dissolution-adsorption effect between CO_(2) and shale.The effects of natural factors,such as shale properties,bedding plane and natural fractures,and controllable factors,proppant,temperature,pressure,CO_(2) concentration and injection rate on fracture initiation and propagation are clarified.The methods of supercritical CO_(2) fracturing process,thickener and proppant optimization to improve the efficiency of supercritical CO_(2) fracturing are discussed.In addition,some new technologies of supercritical CO_(2) fracturing are introduced.The challenges and prospects in the current research are also summarized.For example,supercritical CO_(2) is prone to filtration when passing through porous media,and it is difficult to form a stable flow state.Therefore,in order to achieve stable fracturing fluid suspension and effectively support fractu res,it is urge nt to explo re new fracturing fluid additives or improve fracturing fluid formulations combined with the research of new proppants.This paper is of great significance for understanding the behavior mechanism of supercritical CO_(2) in shale and optimizing fracturing technology.展开更多
文摘Our database tracking of USA water usage per well indicates that traditionally shale operators have been using, on average 3 to 6 million gallons of water; even up to 8 million for the en- tire life cycle of the well based on its suitability for re-fracturing to stimulate their long and lateral ho- rizontal welis. According to our data, sourcing, storage, transportation, treatment, and disposal of this large volume of water could account for up to 10% of overall drilling and completion costs. With in- creasingly stringent regulations governing the use of fresh water and growing challenges associated with storage and use of produced and flowback water in hydraulic fracturing, finding alternative sources of fracturing fluid is already a hot debate among both the scientific community and industry experts. On the other hand, waterless fracturing technology providers claim their technology can solve the concerns of water availability for shale development. This study reviews high-level technical issues and opportunities in this challenging and growing market and evaluates key economic drivers behind water management practices such as waterless fracturing technologies, based on a given shale gas play in the United States and experience gained in Canada. Water costs are analyzed under a variety of scenarios with and without the use of （fresh） water. The results are complemented by surveys from several oil and gas operators. Our economic analysis shows that fresh water usage offers the greatest economic return. In regions where water sourcing is a challenge, however, the short-term economic advantage of using non-fresh water-based fracturing outweighs the capital costs required by waterless fracturing methods. Until waterless methods are cost competitive, recycled water usage with low treatment offers a similar net present value （NPV） to that of sourcing freshwater via truck, for in- stance.
基金This work was supported by the National Natural Science Foundation of China （60977058 ＆ 61475085）, the Science and Technology Development Project of Shandong Province （2014GGX101007）, and the Fundamental Research Funds of Shandong University （2014YQ011）.
文摘A distributed feedback diode laser （DFB-DL） based hygrometer combined with a long-path-length Herriot gas cell and waterless optical components was proposed and investigated. The main function of this sensor was to simultaneously improve the measurement reliability and resolution. A comparison test between a 10-cm normal transmission-type gas cell and a 3-m Herriot gas cell was carried out to demonstrate the improvement. Reliability improvement was achieved by influence suppression of water vapor inside optical components （WVOC） through combined action of the Herriot gas cell and waterless optical components. The influence of WVOC was suppressed from 726ppmv to 25ppmv using the Herriot gas cell. Moreover, combined with waterless optical components, the influence of WVOC was further suppressed to no more than 4ppmv. Resolution improvement from l l.7ppmv to 0.32ppmv was achieved mainly due to the application of the long-path-length Herriot gas cell. The results show that the proposed sensor has a good performance and considerable potential application in gas sensing, especially when probed gas possibly permeates into optical components.
基金supported by Shandong Provincial Natural Science Foundation(Grant No.ZR2022MF244)the Institutional Applied Scientific Research Projects(2021yyx-zd02).
文摘Live fish waterless transportation could be recognized as an essential supplement for water-based transportation due to its low oxygen consumption and less waste water pollution.The critical problem to maintaining the fish survival quality under such a unique transport strategy is accurately controlling the oxygen concentration in the container to be constantly at stable and high levels.This paper aims to propose an improved fuzzy PID control system based on the grey model with residual rectification by improved particle swarm optimized Gated Recurrent Unit(GM-IPSO-GRU)to realize advanced oxygen level control.In addition,it is also reinforced by adopting the improved grey wolf optimization(IGWO)for the majorization of control parameters(quantization factors,scale factors)with full consideration of fish size features.In this study,Turbot(Scophthalmus maximus)is taken as the test subject to verify the integrated control performance of the optimized fuzzy PID controller through simulated waterless live transportation under lowtemperature conditions.The proposed control system is validated as more efficient than the traditional proportional integral derivative(PID)and fuzzy PID algorithms for handling its nonlinear,time-varying,and time lag problems well.In summary,the control group experiment shows that the newly-designed control system has the advantages of shorter stabilization time,minor overshoot,and strong anti-interference ability for oxygen level adjustment.Finally,applying this novel control technology can effectively improve oxygen adjustment efficiency and provide feasible quality control support for the deep optimization of the live fish circulation industry.
文摘With the increasing demand for energy,traditional oil resources are facing depletion and insufficient supply.Many countries are rapidly turning to the development of unconventional oil and gas resources.Among them,shale oil and gas reservoirs have become the focus of unconventional oil and gas resources exploration and development.Based on the characteristics of shale oil and gas reservoirs,supercritical CO_(2) fracturing is more conducive to improving oil recovery than other fracturing technologies.In this paper,the mechanism of fracture initiation and propagation of supercritical CO_(2) in shale is analyzed,including viscosity effect,surface tension effect,permeation diffusion effect of supercritical CO_(2),and dissolution-adsorption effect between CO_(2) and shale.The effects of natural factors,such as shale properties,bedding plane and natural fractures,and controllable factors,proppant,temperature,pressure,CO_(2) concentration and injection rate on fracture initiation and propagation are clarified.The methods of supercritical CO_(2) fracturing process,thickener and proppant optimization to improve the efficiency of supercritical CO_(2) fracturing are discussed.In addition,some new technologies of supercritical CO_(2) fracturing are introduced.The challenges and prospects in the current research are also summarized.For example,supercritical CO_(2) is prone to filtration when passing through porous media,and it is difficult to form a stable flow state.Therefore,in order to achieve stable fracturing fluid suspension and effectively support fractu res,it is urge nt to explo re new fracturing fluid additives or improve fracturing fluid formulations combined with the research of new proppants.This paper is of great significance for understanding the behavior mechanism of supercritical CO_(2) in shale and optimizing fracturing technology.
