Produced water (PW) is the largest waste stream in the oil and gas industry. Water remains trapped for millions of years in the reservoir with oil and gas. When a hydrocarbon reservoir is infiltrated by a production w...Produced water (PW) is the largest waste stream in the oil and gas industry. Water remains trapped for millions of years in the reservoir with oil and gas. When a hydrocarbon reservoir is infiltrated by a production well, the produced fluids commonly contain water. The understanding of this water’s constituents and volumes is vital for the sustainable continuity of production operations, as PW has a number of negative impacts on the infrastructure integrity of the operation. On the other hand, PW can be an alternative source of irrigation water as well as of industrial salt. Interestingly, both the quantity as well as the quality of PW do not remain constant but can vary, both progressively and erratically, even over short periods of time. This paper discusses such a situation of variable PW in an oil and gas operation in the State of Kuwait.展开更多
This paper presents a theoretical method and a finite element method to describe wellhead movement and uncemented casing strength in offshore oil and gas wells.Parameters considered in the theoretical method include o...This paper presents a theoretical method and a finite element method to describe wellhead movement and uncemented casing strength in offshore oil and gas wells.Parameters considered in the theoretical method include operating load during drilling and completion and the temperature field,pressure field and the end effect of pressure during gas production.The finite element method for multistring analysis is developed to simulate random contact between casings.The relevant finite element analysis scheme is also presented according to the actual procedures of drilling,completion and gas production.Finally,field cases are presented and analyzed using the proposed methods.These are four offshore wells in the South China Sea.The calculated wellhead growths during gas production are compared with measured values.The results show that the wellhead subsides during drilling and completion and grows up during gas production.The theoretical and finite element solutions for wellhead growth are in good agreement with measured values and the deviations of calculation are within 10%.The maximum von Mises stress on the uncemented intermediate casing occurs during the running of the oil tube.The maximum von Mises stress on the uncemented production casing,calculated with the theoretical method occurs at removing the blow-out-preventer (BOP) while that calculated with the finite element method occurs at gas production.Finite element solutions for von Mises stress are recommended and the uncemented casings of four wells satisfy strength requirements.展开更多
Traditional methods for judging the degree of insufficient fluid supply in oil wells have low efficiency and limited accuracy. To address this problem, a method for intelligently identifying the degree of insufficient...Traditional methods for judging the degree of insufficient fluid supply in oil wells have low efficiency and limited accuracy. To address this problem, a method for intelligently identifying the degree of insufficient fluid supply in oil wells based on convolutional neural networks is proposed in this paper. Firstly, 5000 indicator diagrams with insufficient liquid supply were collected from the oilfield site, and a sample set was established after preprocessing;then based on the AlexNet model, combined with the characteristics of the indicator diagram, a convolutional neural network model including 4 layers of convolutional layers, 3 layers of down-pooling layers and 2 layers of fully connected layers is established. The backpropagation, ReLu activation function and dropout regularization method are used to complete the training of the convolutional neural network;finally, the performance of the convolutional neural network under different iteration times and network structure is compared, and the super parameter optimization of the model is completed. It has laid a good foundation for realizing the self-adaptive and intelligent matching of oil well production parameters and formation fluid supply conditions. It has certain application prospects. The results show that the accuracy of training and verification of the method exceeds 98%, which can meet the actual application requirements on site.展开更多
By reviewing the development of “three-high” oil and gas well testing technology of Sinopec in recent years, this paper systematically summarizes the application of “three-high” oil and gas well testing technology...By reviewing the development of “three-high” oil and gas well testing technology of Sinopec in recent years, this paper systematically summarizes the application of “three-high” oil and gas well testing technology of Sinopec in engineering optimization design technology, and high temperature and high pressure testing technology, high pressure and high temperature transformation completion integration technology. Major progress has been made in seven aspects: plug removal and re-production technology of production wells in high acid gas fields;wellbore preparation technology of ultra-deep, high-pressure, and high-temperature oil and gas wells;surface metering technology;and supporting tool development technology. This paper comprehensively analyzes the challenges faced by the “three-high” oil and gas well production testing technology in four aspects: downhole tools, production testing technology, safe production testing, and the development of low-cost production test tools. Four development directions are put forward: 1) Improve ultra-deep oil and gas testing technology and strengthen integrated geological engineering research. 2) Deepen oil and gas well integrity evaluation technology to ensure the life cycle of oil and gas wells. 3) Carry out high-end, customized, and intelligent research on oil test tools to promote the low-cost and efficient development of ultra deep reservoirs. 4) Promote the fully automatic control of the surface metering process to realize the safe development of “three-high” reservoirs.展开更多
In the petroleum industry,detection of multi-phase fluid flow is very important in both surface and down-hole measurements.Accurate measurement of high rate of water or gas multi-phase flow has always been an academic...In the petroleum industry,detection of multi-phase fluid flow is very important in both surface and down-hole measurements.Accurate measurement of high rate of water or gas multi-phase flow has always been an academic and industrial focus.NMR is an efficient and accurate technique for the detection of fluids;it is widely used in the determination of fluid compositions and properties.This paper is aimed to quantitatively detect multi-phase flow in oil and gas wells and pipelines and to propose an innovative method for online nuclear magnetic resonance(NMR)detection.The online NMR data acquisition,processing and interpretation methods are proposed to fill the blank of traditional methods.A full-bore straight tube design without pressure drop,a Halbach magnet structure design with zero magnetic leakage outside the probe,a separate antenna structure design without flowing effects on NMR measurement and automatic control technology will achieve unattended operation.Through the innovation of this work,the application of NMR for the real-time and quantitative detection of multi-phase flow in oil and gas wells and pipelines can be implemented.展开更多
In this article, the recent research achievements on the theory and technology of condensate oil and gas wells stimulated by electromagnetic induction heating during middle or late exploitation period were introduced ...In this article, the recent research achievements on the theory and technology of condensate oil and gas wells stimulated by electromagnetic induction heating during middle or late exploitation period were introduced for the first time at home and abroad. A new kind of electromagnetic wave induction heating equipment XAEMH-1 was developed. Taking near wellbore zone temperature field as the main research object, which is the key factor for the condensation and retrograde vaporization during electromagnetic heating, the mathematical simulation model for a condensate oil and gas well stimulated by electromagnetic heating to eliminate blockage near wellbore region was established. A corresponding computer system was developed to dynamically predict and evaluate the efficiency of this electromagnetic heating process. Through this computer system, the near wellbore region distributions of several important factors such as temperature, pressure, condensate oil saturation and relative permeability can be described quantitatively. A condensate gas well in a late exploitation period reservoir here in China was chosen as a practical example to test the effectiveness of this new technology and some satisfactory results were obtained. These results proved that it is feasible to eliminate the near wellbore region blockage by electromagnetic heating. A new prospective stimulation method was given for the condensate oil and gas reservoirs during middle or late exploitation period.展开更多
The most common way to achieve an enormous production rate of a reservoir is to increase drawdown pressure during the production procedure by decreasing the bottom-hole pressure.This process was done by artificial pat...The most common way to achieve an enormous production rate of a reservoir is to increase drawdown pressure during the production procedure by decreasing the bottom-hole pressure.This process was done by artificial patterns like a gas lift.Nowadays,most of the wells worldwide due to years of production and reducing the amount of energy which was supplied by natural drive mechanisms are being placed on artificial lift methodologies.Hence,the number of wells that used this method will continue to increase.The primary purposes in the gas lift design of a wellbore are to determine the proper depths and the location of valve installation,select appropriate flow regime during the pipeline and calibrate the pressures of the operating and unloading valves.The purpose of this research is to design gas lift system in the oil wells of on the south fields of Iran by considering the maximum production connate water volume of 40 percent and average pressure drop(20-25 psia)throughout the year regarding production continuously or increasing the flow rate of the wells.Therefore,20 wells that their number starts A to T with this locations L280N,W115S and W002S are the candidates for gas lift procedures.Furthermore,the appropriate flow regimes through the well are being studied,and the most proper method for gas lifting and required surficial equipment will be designed for this field.Consequently,due to increasing the volume of gas and connate water among the production after gas lifting,fundamental changes on the equipment,flow regimes and gas lift system are being proposed that production will be done by proper engineering method.In the well gas lift design,Beggs&Brill Revised method is being selected for hydraulic calculation of pipeline flow due to low errors.展开更多
The situation of an off-center casing under non-uniform ground stress can occur in the process of drilling a salt-gypsum formation,and the related casing stress calculation has not yet been solved analytically. In add...The situation of an off-center casing under non-uniform ground stress can occur in the process of drilling a salt-gypsum formation,and the related casing stress calculation has not yet been solved analytically. In addition,the experimental equipment in many cases cannot meet the actual conditions and the experimental cost is very high. These comprehensive factors cause the existing casing design to not meet the actual conditions and cause casing deformation,affecting the drilling operation in Tarim oil field. The finite element method is the only effective method to solve this problem at present,but the re-modelling process is time-consuming because of the changes in the parameters,such as the cement properties,casing centrality,and the casing size. In this article,an artificial intelligence method based on support vector machine(SVM) to predict the maximum stress of an offcenter casing under non-uniform ground stress has been proposed. After a program based on a radial basis function(RBF)-support vector regression(SVR)(ε-SVR) model was established and validated,we constructed a data sample with a capacity of 120 by using the finite element method,which could meet the demand of the nine-factor ε-SVR model to predict the maximum stress of the casing. The results showed that the artificial intelligence prediction method proposed in this manuscript had satisfactory prediction accuracy and could be effectively used to predict the maximum stress of an off-center casing under complex downhole conditions.展开更多
文摘Produced water (PW) is the largest waste stream in the oil and gas industry. Water remains trapped for millions of years in the reservoir with oil and gas. When a hydrocarbon reservoir is infiltrated by a production well, the produced fluids commonly contain water. The understanding of this water’s constituents and volumes is vital for the sustainable continuity of production operations, as PW has a number of negative impacts on the infrastructure integrity of the operation. On the other hand, PW can be an alternative source of irrigation water as well as of industrial salt. Interestingly, both the quantity as well as the quality of PW do not remain constant but can vary, both progressively and erratically, even over short periods of time. This paper discusses such a situation of variable PW in an oil and gas operation in the State of Kuwait.
基金financial support from the National Key Sci-Tech Major Special Item(No.2011ZX05026-001)Program for Changjiang Scholars and Innovative Research Team in University(IRT1086)
文摘This paper presents a theoretical method and a finite element method to describe wellhead movement and uncemented casing strength in offshore oil and gas wells.Parameters considered in the theoretical method include operating load during drilling and completion and the temperature field,pressure field and the end effect of pressure during gas production.The finite element method for multistring analysis is developed to simulate random contact between casings.The relevant finite element analysis scheme is also presented according to the actual procedures of drilling,completion and gas production.Finally,field cases are presented and analyzed using the proposed methods.These are four offshore wells in the South China Sea.The calculated wellhead growths during gas production are compared with measured values.The results show that the wellhead subsides during drilling and completion and grows up during gas production.The theoretical and finite element solutions for wellhead growth are in good agreement with measured values and the deviations of calculation are within 10%.The maximum von Mises stress on the uncemented intermediate casing occurs during the running of the oil tube.The maximum von Mises stress on the uncemented production casing,calculated with the theoretical method occurs at removing the blow-out-preventer (BOP) while that calculated with the finite element method occurs at gas production.Finite element solutions for von Mises stress are recommended and the uncemented casings of four wells satisfy strength requirements.
文摘Traditional methods for judging the degree of insufficient fluid supply in oil wells have low efficiency and limited accuracy. To address this problem, a method for intelligently identifying the degree of insufficient fluid supply in oil wells based on convolutional neural networks is proposed in this paper. Firstly, 5000 indicator diagrams with insufficient liquid supply were collected from the oilfield site, and a sample set was established after preprocessing;then based on the AlexNet model, combined with the characteristics of the indicator diagram, a convolutional neural network model including 4 layers of convolutional layers, 3 layers of down-pooling layers and 2 layers of fully connected layers is established. The backpropagation, ReLu activation function and dropout regularization method are used to complete the training of the convolutional neural network;finally, the performance of the convolutional neural network under different iteration times and network structure is compared, and the super parameter optimization of the model is completed. It has laid a good foundation for realizing the self-adaptive and intelligent matching of oil well production parameters and formation fluid supply conditions. It has certain application prospects. The results show that the accuracy of training and verification of the method exceeds 98%, which can meet the actual application requirements on site.
文摘By reviewing the development of “three-high” oil and gas well testing technology of Sinopec in recent years, this paper systematically summarizes the application of “three-high” oil and gas well testing technology of Sinopec in engineering optimization design technology, and high temperature and high pressure testing technology, high pressure and high temperature transformation completion integration technology. Major progress has been made in seven aspects: plug removal and re-production technology of production wells in high acid gas fields;wellbore preparation technology of ultra-deep, high-pressure, and high-temperature oil and gas wells;surface metering technology;and supporting tool development technology. This paper comprehensively analyzes the challenges faced by the “three-high” oil and gas well production testing technology in four aspects: downhole tools, production testing technology, safe production testing, and the development of low-cost production test tools. Four development directions are put forward: 1) Improve ultra-deep oil and gas testing technology and strengthen integrated geological engineering research. 2) Deepen oil and gas well integrity evaluation technology to ensure the life cycle of oil and gas wells. 3) Carry out high-end, customized, and intelligent research on oil test tools to promote the low-cost and efficient development of ultra deep reservoirs. 4) Promote the fully automatic control of the surface metering process to realize the safe development of “three-high” reservoirs.
基金supported by the National Natural Science Foundation of China(Grant No.51704327)
文摘In the petroleum industry,detection of multi-phase fluid flow is very important in both surface and down-hole measurements.Accurate measurement of high rate of water or gas multi-phase flow has always been an academic and industrial focus.NMR is an efficient and accurate technique for the detection of fluids;it is widely used in the determination of fluid compositions and properties.This paper is aimed to quantitatively detect multi-phase flow in oil and gas wells and pipelines and to propose an innovative method for online nuclear magnetic resonance(NMR)detection.The online NMR data acquisition,processing and interpretation methods are proposed to fill the blank of traditional methods.A full-bore straight tube design without pressure drop,a Halbach magnet structure design with zero magnetic leakage outside the probe,a separate antenna structure design without flowing effects on NMR measurement and automatic control technology will achieve unattended operation.Through the innovation of this work,the application of NMR for the real-time and quantitative detection of multi-phase flow in oil and gas wells and pipelines can be implemented.
基金Project supported by the National Basic Research Program of China (973 Program,Grant No. 2001CB2091-06-04).
文摘In this article, the recent research achievements on the theory and technology of condensate oil and gas wells stimulated by electromagnetic induction heating during middle or late exploitation period were introduced for the first time at home and abroad. A new kind of electromagnetic wave induction heating equipment XAEMH-1 was developed. Taking near wellbore zone temperature field as the main research object, which is the key factor for the condensation and retrograde vaporization during electromagnetic heating, the mathematical simulation model for a condensate oil and gas well stimulated by electromagnetic heating to eliminate blockage near wellbore region was established. A corresponding computer system was developed to dynamically predict and evaluate the efficiency of this electromagnetic heating process. Through this computer system, the near wellbore region distributions of several important factors such as temperature, pressure, condensate oil saturation and relative permeability can be described quantitatively. A condensate gas well in a late exploitation period reservoir here in China was chosen as a practical example to test the effectiveness of this new technology and some satisfactory results were obtained. These results proved that it is feasible to eliminate the near wellbore region blockage by electromagnetic heating. A new prospective stimulation method was given for the condensate oil and gas reservoirs during middle or late exploitation period.
文摘The most common way to achieve an enormous production rate of a reservoir is to increase drawdown pressure during the production procedure by decreasing the bottom-hole pressure.This process was done by artificial patterns like a gas lift.Nowadays,most of the wells worldwide due to years of production and reducing the amount of energy which was supplied by natural drive mechanisms are being placed on artificial lift methodologies.Hence,the number of wells that used this method will continue to increase.The primary purposes in the gas lift design of a wellbore are to determine the proper depths and the location of valve installation,select appropriate flow regime during the pipeline and calibrate the pressures of the operating and unloading valves.The purpose of this research is to design gas lift system in the oil wells of on the south fields of Iran by considering the maximum production connate water volume of 40 percent and average pressure drop(20-25 psia)throughout the year regarding production continuously or increasing the flow rate of the wells.Therefore,20 wells that their number starts A to T with this locations L280N,W115S and W002S are the candidates for gas lift procedures.Furthermore,the appropriate flow regimes through the well are being studied,and the most proper method for gas lifting and required surficial equipment will be designed for this field.Consequently,due to increasing the volume of gas and connate water among the production after gas lifting,fundamental changes on the equipment,flow regimes and gas lift system are being proposed that production will be done by proper engineering method.In the well gas lift design,Beggs&Brill Revised method is being selected for hydraulic calculation of pipeline flow due to low errors.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.U1663205,51704191 and 51804194)the Shanghai Leading Academic Discipline Project(Grant No.S30106)+1 种基金the Shanghai Municipal Education Commission(Peak Discipline Construction Program)the Shanghai Sailing Program(Grant No.17YF1428000)。
文摘The situation of an off-center casing under non-uniform ground stress can occur in the process of drilling a salt-gypsum formation,and the related casing stress calculation has not yet been solved analytically. In addition,the experimental equipment in many cases cannot meet the actual conditions and the experimental cost is very high. These comprehensive factors cause the existing casing design to not meet the actual conditions and cause casing deformation,affecting the drilling operation in Tarim oil field. The finite element method is the only effective method to solve this problem at present,but the re-modelling process is time-consuming because of the changes in the parameters,such as the cement properties,casing centrality,and the casing size. In this article,an artificial intelligence method based on support vector machine(SVM) to predict the maximum stress of an offcenter casing under non-uniform ground stress has been proposed. After a program based on a radial basis function(RBF)-support vector regression(SVR)(ε-SVR) model was established and validated,we constructed a data sample with a capacity of 120 by using the finite element method,which could meet the demand of the nine-factor ε-SVR model to predict the maximum stress of the casing. The results showed that the artificial intelligence prediction method proposed in this manuscript had satisfactory prediction accuracy and could be effectively used to predict the maximum stress of an off-center casing under complex downhole conditions.