This paper provides a comprehensive overview of Deep Transient Testing(DTT),a cutting-edge technique for reservoir characterization that has revolutionized the oil and gas industry.The main aim of DTT is to characteri...This paper provides a comprehensive overview of Deep Transient Testing(DTT),a cutting-edge technique for reservoir characterization that has revolutionized the oil and gas industry.The main aim of DTT is to characterize the reservoir with a deeper radius of investigation.The optimization of the radius of investigation with the DTT approach is studied in detail.Reveal is a commercial numerical simulation application used to simulate the DTT process and evaluate the pressure wave analysis in the porous media.The main aim of the simulation is to understand the impact of the reservoir quality on the pressure response and use it to address the noise-to-pule ratio,which is a determinantal parameter in testing duration.The tested wells with the DTT tool show that measured well productivity can deliver the minimum commercial rate.The has been delivered within 2 days compared to the potential test time of 21 days which saved the 19 rig days and contributed to C02 emission reduction of(gas flaring 1340+rig emission 600)1940 Metric tons equivalent to 421 cars emission in a year.However,DTT also presents certain limitations,such as the requirement for specialized equipment and expertise,as well as the potential for formation damage during testing.This study provides a detailed description of the DTT technique,encompassing its history,theory,and practical applications.Furthermore,it discusses the benefits and limitations of DTT and presents case studies to illustrate its effectiveness across various reservoir types.Overall,this study serves as a valuable resource for reservoir engineers,geologists,and other professionals involved in the exploration and production of oil and gas.展开更多
During the test on transient pressure signal in explosion field,false trigger caused by field interference can lead to test failure.To improve the stability of test system,a signal detection and recognition technology...During the test on transient pressure signal in explosion field,false trigger caused by field interference can lead to test failure.To improve the stability of test system,a signal detection and recognition technology is proposed for transient pressure test system.In the process of signal acquisition,firstly,electrical levels are monitored in real time to find effective abrupt changes and mark them;then the effective data segments are detecdted totected;thus the effective signals can be acquired in turn finally.The experimental results show that the shock wave signal can be collected effectively and the reliability of the test system can be improved after removal of interferences.展开更多
In the transient process of power grid faults,the transferring distortion of current transformer(CT)can seriously affect relay protection performance.Under these conditions,it is difficult to analyze the ferromagnetic...In the transient process of power grid faults,the transferring distortion of current transformer(CT)can seriously affect relay protection performance.Under these conditions,it is difficult to analyze the ferromagnetic characteristic of the magnetizing branch in the transient equivalent circuit of CT.The Jiles-Atherton hysteresis model(J-A model),which is widely used in digital simulations,can accurately describe the hysteresis and saturation process of the core characteristics;however,to acquire the parameters of the J-A model of current transformers in practical use is still a challenging problem.In this paper,physical tests based on a practical CT and parameter identification are presented to solve the problem.The basic hysteresis loops of P,PR,and TPY class of practical current transformers are obtained through physical tests.Thus,the J-A model parameters are identified using a hybrid genetic/simulated annealing algorithm,based on which transient simulation models of different class CTs are constructed.The effectiveness of the proposed method is verified via dynamic physical simulation tests.A typical accident is analyzed based on these models.展开更多
The current research about the flow ripple of axial piston pump mainly focuses on the effect of the structure of parts on the flow ripple. Therein, the structure of parts are usually designed and optimized at rated wo...The current research about the flow ripple of axial piston pump mainly focuses on the effect of the structure of parts on the flow ripple. Therein, the structure of parts are usually designed and optimized at rated working conditions. However, the pump usually has to work in large-scale and time-variant working conditions. Therefore, the flow ripple characteristics of pump and analysis for its test accuracy with respect to variant steady-state conditions and transient conditions in a wide range of operating parameters are focused in this paper. First, a simulation model has been constructed, which takes the kinematics of oil film within friction pairs into account for higher accuracy. Afterwards, a test bed which adopts Secondary Source Method is built to verify the model. The simulation and tests results show that the angular position of the piston, corresponding to the position where the peak flow ripple is produced, varies with the different pressure. The pulsating amplitude and pulsation rate of flow ripple increase with the rise of pressure and the variation rate of pressure. For the pump working at a constant speed, the flow pulsation rate decreases dramatically with the increasing speed when the speed is less than 27.78% of the maximum speed, subsequently presents a small decrease tendency with the speed further increasing. With the rise of the variation rate of speed, the pulsating amplitude and pulsation rate of flow ripple increase. As the swash plate angle augments, the pulsating amplitude of flow ripple increases, nevertheless the flow pulsation rate decreases. In contrast with the effect of the variation of pressure, the test accuracy of flow ripple is more sensitive to the variation of speed. It makes the test accuracy above 96.20% available for the pulsating amplitude of pressure deviating within a range of ~6% from the mean pressure. However, with a variation of speed deviating within a range of ±2% from the mean speed, the attainable test accuracy of flow ripple is above 93.07%. The model constructed in this research proposes a method to determine the flow ripple characteristics of pump and its attainable test accuracy under the large-scale and time-variant working conditions. Meanwhile, a discussion about the variation of flow ripple and its obtainable test accuracy with the conditions of the pump working in wide operating ranges is given as well.展开更多
文摘This paper provides a comprehensive overview of Deep Transient Testing(DTT),a cutting-edge technique for reservoir characterization that has revolutionized the oil and gas industry.The main aim of DTT is to characterize the reservoir with a deeper radius of investigation.The optimization of the radius of investigation with the DTT approach is studied in detail.Reveal is a commercial numerical simulation application used to simulate the DTT process and evaluate the pressure wave analysis in the porous media.The main aim of the simulation is to understand the impact of the reservoir quality on the pressure response and use it to address the noise-to-pule ratio,which is a determinantal parameter in testing duration.The tested wells with the DTT tool show that measured well productivity can deliver the minimum commercial rate.The has been delivered within 2 days compared to the potential test time of 21 days which saved the 19 rig days and contributed to C02 emission reduction of(gas flaring 1340+rig emission 600)1940 Metric tons equivalent to 421 cars emission in a year.However,DTT also presents certain limitations,such as the requirement for specialized equipment and expertise,as well as the potential for formation damage during testing.This study provides a detailed description of the DTT technique,encompassing its history,theory,and practical applications.Furthermore,it discusses the benefits and limitations of DTT and presents case studies to illustrate its effectiveness across various reservoir types.Overall,this study serves as a valuable resource for reservoir engineers,geologists,and other professionals involved in the exploration and production of oil and gas.
基金The 11th Postgraduate Technology Innovation Project of North University of China(No.20141142)
文摘During the test on transient pressure signal in explosion field,false trigger caused by field interference can lead to test failure.To improve the stability of test system,a signal detection and recognition technology is proposed for transient pressure test system.In the process of signal acquisition,firstly,electrical levels are monitored in real time to find effective abrupt changes and mark them;then the effective data segments are detecdted totected;thus the effective signals can be acquired in turn finally.The experimental results show that the shock wave signal can be collected effectively and the reliability of the test system can be improved after removal of interferences.
基金supported by the Key project of smart grid technology and equipment of national key research and development plan of China under Grant 2016YFB0900600。
文摘In the transient process of power grid faults,the transferring distortion of current transformer(CT)can seriously affect relay protection performance.Under these conditions,it is difficult to analyze the ferromagnetic characteristic of the magnetizing branch in the transient equivalent circuit of CT.The Jiles-Atherton hysteresis model(J-A model),which is widely used in digital simulations,can accurately describe the hysteresis and saturation process of the core characteristics;however,to acquire the parameters of the J-A model of current transformers in practical use is still a challenging problem.In this paper,physical tests based on a practical CT and parameter identification are presented to solve the problem.The basic hysteresis loops of P,PR,and TPY class of practical current transformers are obtained through physical tests.Thus,the J-A model parameters are identified using a hybrid genetic/simulated annealing algorithm,based on which transient simulation models of different class CTs are constructed.The effectiveness of the proposed method is verified via dynamic physical simulation tests.A typical accident is analyzed based on these models.
基金Supported by National Basic Research Program of China(973 Program,Grant No.2014CB046403)National Key Technology R&D Program of the Twelfth Five-year Plan of China(Grant No.2013BAF07B01)
文摘The current research about the flow ripple of axial piston pump mainly focuses on the effect of the structure of parts on the flow ripple. Therein, the structure of parts are usually designed and optimized at rated working conditions. However, the pump usually has to work in large-scale and time-variant working conditions. Therefore, the flow ripple characteristics of pump and analysis for its test accuracy with respect to variant steady-state conditions and transient conditions in a wide range of operating parameters are focused in this paper. First, a simulation model has been constructed, which takes the kinematics of oil film within friction pairs into account for higher accuracy. Afterwards, a test bed which adopts Secondary Source Method is built to verify the model. The simulation and tests results show that the angular position of the piston, corresponding to the position where the peak flow ripple is produced, varies with the different pressure. The pulsating amplitude and pulsation rate of flow ripple increase with the rise of pressure and the variation rate of pressure. For the pump working at a constant speed, the flow pulsation rate decreases dramatically with the increasing speed when the speed is less than 27.78% of the maximum speed, subsequently presents a small decrease tendency with the speed further increasing. With the rise of the variation rate of speed, the pulsating amplitude and pulsation rate of flow ripple increase. As the swash plate angle augments, the pulsating amplitude of flow ripple increases, nevertheless the flow pulsation rate decreases. In contrast with the effect of the variation of pressure, the test accuracy of flow ripple is more sensitive to the variation of speed. It makes the test accuracy above 96.20% available for the pulsating amplitude of pressure deviating within a range of ~6% from the mean pressure. However, with a variation of speed deviating within a range of ±2% from the mean speed, the attainable test accuracy of flow ripple is above 93.07%. The model constructed in this research proposes a method to determine the flow ripple characteristics of pump and its attainable test accuracy under the large-scale and time-variant working conditions. Meanwhile, a discussion about the variation of flow ripple and its obtainable test accuracy with the conditions of the pump working in wide operating ranges is given as well.
