T. Adeyemi, Chen Wei, Jyotsna Sharma, Yuanhang Chen
Accurate estimation and prediction of gas rise velocity, length of the gas influx region, and void fraction are important for optimal gas kick removal, riser gas management, and well control planning. These parameters are also essential in monitoring and characterization of multiphase flow. However, gas dynamics in non-Newtonian fluids, such as drilling mud, which is essential for gas influx control, are poorly understood due to the inability to create full-scale annular flow conditions that approximate the conditions observed in the field. This results in a lack of understanding and poor prediction of gas kick behavior in the field. To bridge this gap, we use distributed fiber-optic sensors (DFOS) for real-time estimation of gas rise velocity, void fraction, and influx length in water and oil-based mud (OBM) at the well scale. DFOS can overcome a major limitation of downhole gauges and logging tools by enabling the in-situ monitoring of dynamic events simultaneously across the entire wellbore. This study is the first well-scale deployment of distributed acoustic sensor (DAS), distributed temperature sensor (DTS), and distributed strain sensor (DSS) for investigation of gas behavior in water and OBM. Gas void fraction, migration velocities, and gas influx lengths were analyzed across a 5,163-ft-deep wellbore for multiphase experiments conducted with nitrogen in water and nitrogen in synthetic-based mud, at similar operating conditions. An improved transient drift flux–based numerical model was developed to simulate the experimental processes and understand the gas dynamics in different wellbore fluid environments. The gas velocities, void fractions, and gas influx lengths estimated independently using DAS, DTS, and DSS showed good agreement with the simulation results, as well as the downhole gauge analysis.
{"title":"Comparison of Gas Signature and Void Fraction in Water- and Oil-Based Muds Using Fiber-Optic Distributed Acoustic Sensor, Distributed Temperature Sensor, and Distributed Strain Sensor","authors":"T. Adeyemi, Chen Wei, Jyotsna Sharma, Yuanhang Chen","doi":"10.2118/219753-pa","DOIUrl":"https://doi.org/10.2118/219753-pa","url":null,"abstract":"\u0000 Accurate estimation and prediction of gas rise velocity, length of the gas influx region, and void fraction are important for optimal gas kick removal, riser gas management, and well control planning. These parameters are also essential in monitoring and characterization of multiphase flow. However, gas dynamics in non-Newtonian fluids, such as drilling mud, which is essential for gas influx control, are poorly understood due to the inability to create full-scale annular flow conditions that approximate the conditions observed in the field. This results in a lack of understanding and poor prediction of gas kick behavior in the field. To bridge this gap, we use distributed fiber-optic sensors (DFOS) for real-time estimation of gas rise velocity, void fraction, and influx length in water and oil-based mud (OBM) at the well scale.\u0000 DFOS can overcome a major limitation of downhole gauges and logging tools by enabling the in-situ monitoring of dynamic events simultaneously across the entire wellbore. This study is the first well-scale deployment of distributed acoustic sensor (DAS), distributed temperature sensor (DTS), and distributed strain sensor (DSS) for investigation of gas behavior in water and OBM. Gas void fraction, migration velocities, and gas influx lengths were analyzed across a 5,163-ft-deep wellbore for multiphase experiments conducted with nitrogen in water and nitrogen in synthetic-based mud, at similar operating conditions. An improved transient drift flux–based numerical model was developed to simulate the experimental processes and understand the gas dynamics in different wellbore fluid environments. The gas velocities, void fractions, and gas influx lengths estimated independently using DAS, DTS, and DSS showed good agreement with the simulation results, as well as the downhole gauge analysis.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140783088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Understanding emulsion evolution at static conditions is crucial for production operations, such as pipeline operations during the shut-in and restart process and separator optimal design. This study experimentally investigated the temporal and spatial evolution of water-in-oil emulsion properties under static conditions. Numerical simulations were conducted to study their impacts on pipeline restart operations. The experiments were conducted in graduated glass cylinders, with mineral oil and tap water as the testing fluids and Span® 80 as the surfactant. Different water cuts, mixing speeds, and surfactant concentrations were investigated. Along with idle time at static conditions, the mixture demonstrated two layers, namely an upper oil layer and a lower emulsion layer, except for the lowest surfactant concentration that gave a third additional free-water layer at the bottom. Experimental results showed a dramatic increase in viscosity in the emulsion layer with time and depth, which was closely related to the increase in the water volumetric fraction. The increase rate slowed down and plateaued out with time. The increase rate is also related to water cut, mixing speed, and surfactant concentration. Experimental results also show that the relationships between the viscosity and water cut for separated emulsion follow the master curve of viscosity and water cut for homogeneous emulsion. This suggests that one can estimate the viscosity using the master curve given the water volumetric fraction. The numerical simulation was conducted for pipelines with a valley configuration and with the fluid properties obtained from the experimental measurements. It demonstrates that a higher pressure is required to restart the flow to the original flow rate. It also shows that the flow rate may not be able to resume its original value given the same pressure boundaries due to the accumulation of dense emulsion layers in the horizontal and upward inclined sections. For example, for a 16-m pipe, the flow cannot be restarted given the same inlet pressure (100 Pa). It can only resume 4.6% of the original flow rate when the pressure is elevated to 300 Pa.
了解静态条件下的乳状液演变对于生产操作至关重要，例如停产和重启过程中的管道操作以及分离器的优化设计。本研究通过实验研究了静态条件下油包水乳化液特性的时间和空间演变。并进行了数值模拟，以研究其对管道重启操作的影响。实验在刻度玻璃缸中进行，测试流体为矿物油和自来水，表面活性剂为 Span® 80。研究了不同的截水量、混合速度和表面活性剂浓度。在静态条件下，随着闲置时间的延长，混合物显示出两层，即上层油层和下层乳液层，但表面活性剂浓度最低时，底部会出现第三层额外的自由水层。实验结果表明，随着时间和深度的增加，乳液层的粘度急剧上升，这与水体积分数的增加密切相关。随着时间的推移，增加速度减慢并趋于稳定。粘度增加率还与切水量、搅拌速度和表面活性剂浓度有关。实验结果还表明，分离乳液的粘度和断水量之间的关系遵循均质乳液粘度和断水量的主曲线。这表明，在给定水体积分数的情况下，可以利用主曲线估算粘度。数值模拟是针对具有山谷结构的管道和实验测量获得的流体特性进行的。结果表明，需要更高的压力才能使水流重新达到原来的流速。它还表明，由于在水平段和向上倾斜段积累了致密的乳化层，在压力边界不变的情况下，流速可能无法恢复到原来的值。例如，对于 16 米长的管道，在相同的入口压力（100 帕）下，流量无法恢复。当压力升高到 300 Pa 时，流量只能恢复到原来的 4.6%。
{"title":"Water-in-Oil Emulsion Temporal and Spatial Evolution at Static Conditions and Its Impact on Pipeline Restart","authors":"Denghong Zhou, Kanat Karatayev, Yilin Fan","doi":"10.2118/219741-pa","DOIUrl":"https://doi.org/10.2118/219741-pa","url":null,"abstract":"\u0000 Understanding emulsion evolution at static conditions is crucial for production operations, such as pipeline operations during the shut-in and restart process and separator optimal design. This study experimentally investigated the temporal and spatial evolution of water-in-oil emulsion properties under static conditions. Numerical simulations were conducted to study their impacts on pipeline restart operations.\u0000 The experiments were conducted in graduated glass cylinders, with mineral oil and tap water as the testing fluids and Span® 80 as the surfactant. Different water cuts, mixing speeds, and surfactant concentrations were investigated. Along with idle time at static conditions, the mixture demonstrated two layers, namely an upper oil layer and a lower emulsion layer, except for the lowest surfactant concentration that gave a third additional free-water layer at the bottom. Experimental results showed a dramatic increase in viscosity in the emulsion layer with time and depth, which was closely related to the increase in the water volumetric fraction. The increase rate slowed down and plateaued out with time. The increase rate is also related to water cut, mixing speed, and surfactant concentration. Experimental results also show that the relationships between the viscosity and water cut for separated emulsion follow the master curve of viscosity and water cut for homogeneous emulsion. This suggests that one can estimate the viscosity using the master curve given the water volumetric fraction.\u0000 The numerical simulation was conducted for pipelines with a valley configuration and with the fluid properties obtained from the experimental measurements. It demonstrates that a higher pressure is required to restart the flow to the original flow rate. It also shows that the flow rate may not be able to resume its original value given the same pressure boundaries due to the accumulation of dense emulsion layers in the horizontal and upward inclined sections. For example, for a 16-m pipe, the flow cannot be restarted given the same inlet pressure (100 Pa). It can only resume 4.6% of the original flow rate when the pressure is elevated to 300 Pa.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140774454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ao Li, Hongquan Chen, Ridwan Jalali, Abdulaziz Al-Darrab
Monitoring of subsurface fluid motion is critical for optimizing hydrocarbon production and CO2 sequestration. Streamlines are frequently used to visualize fluid flow; however, they provide only an instantaneous snapshot of the velocity field and do not offer an exact representation of fluid movement under varying field conditions. In contrast, pathlines are constructed by tracking individual particles within the fluid, enabling us to trace the movement of these particles as they traverse through changing velocity fields. Pathline is the trajectory that an individual fluid particle follows in the reservoir. It can be thought of as “recording” the path of a fluid element in the flow field for a given time interval. Pathlines are distinct from streamlines which represent a snapshot of the velocity field at a given instant. The direction the path takes is determined by the streamlines at a specific instant. To start with, streamlines are traced based on the grid face fluxes of finite-difference simulation. Streamline tracing continues till the time of flight equals the current time. The endpoints of the current streamlines become the starting points for the next tracing period. Thus, our formulation incorporates changing flow fields, and the process is repeated for each time interval until the end. The proposed injection monitoring method is tested using a 3D field-scale model with complex geologic features to demonstrate its power and utility. The pathlines were compared with streamlines, as well as the water saturation distribution. Three scenarios are tested: a constant well schedule, a changing well schedule with partial shut-in, and a changing well schedule with a whole field cessation. Results indicate that the pathline provides a more accurate swept volume, consistent with saturation distribution. The robustness of our algorithm and implementation is demonstrated with a complex embedded discrete fracture model (EDFM) to visualize flow patterns in discrete facture network. Pathlines display the fluid flow across fractures and are subsequently used to explore the sweep efficiency and the well connectivity.
{"title":"From Streamline to Pathline: Visualizing Particle Trajectories Under Changing Velocity Fields","authors":"Ao Li, Hongquan Chen, Ridwan Jalali, Abdulaziz Al-Darrab","doi":"10.2118/215088-pa","DOIUrl":"https://doi.org/10.2118/215088-pa","url":null,"abstract":"\u0000 Monitoring of subsurface fluid motion is critical for optimizing hydrocarbon production and CO2 sequestration. Streamlines are frequently used to visualize fluid flow; however, they provide only an instantaneous snapshot of the velocity field and do not offer an exact representation of fluid movement under varying field conditions. In contrast, pathlines are constructed by tracking individual particles within the fluid, enabling us to trace the movement of these particles as they traverse through changing velocity fields.\u0000 Pathline is the trajectory that an individual fluid particle follows in the reservoir. It can be thought of as “recording” the path of a fluid element in the flow field for a given time interval. Pathlines are distinct from streamlines which represent a snapshot of the velocity field at a given instant. The direction the path takes is determined by the streamlines at a specific instant. To start with, streamlines are traced based on the grid face fluxes of finite-difference simulation. Streamline tracing continues till the time of flight equals the current time. The endpoints of the current streamlines become the starting points for the next tracing period. Thus, our formulation incorporates changing flow fields, and the process is repeated for each time interval until the end.\u0000 The proposed injection monitoring method is tested using a 3D field-scale model with complex geologic features to demonstrate its power and utility. The pathlines were compared with streamlines, as well as the water saturation distribution. Three scenarios are tested: a constant well schedule, a changing well schedule with partial shut-in, and a changing well schedule with a whole field cessation. Results indicate that the pathline provides a more accurate swept volume, consistent with saturation distribution. The robustness of our algorithm and implementation is demonstrated with a complex embedded discrete fracture model (EDFM) to visualize flow patterns in discrete facture network. Pathlines display the fluid flow across fractures and are subsequently used to explore the sweep efficiency and the well connectivity.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140762966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
With the development of unconventional resources, such as oil sands and methane hydrate reservoirs, the importance of the mechanical performance model for underground unconsolidated rocks has increased significantly. The commonly used numerical approach for unconsolidated rocks is the discrete-element method (DEM). However, the extensive calculations required by the DEM make it inadequate for simulating unconsolidated rock behavior on a field scale. An alternative is the continuum approach, used to simulate the behavior of unconsolidated rocks on the field scale. In previous continuum approaches, unconsolidated rocks have been modeled as a visco-plastic fluid (i.e., Bingham fluid). The continuum approach based on visco-plastic fluid uses pressure (scalar) to describe the stress state of the particles. However, this approach does not account for the difference between the maximum and minimum principal stresses of the in-situ stress field when simulating the mechanical performance of unconsolidated rocks. Here, we developed an improved continuum approach for unconsolidated rocks and used the finite-element method as a numerical approach. Our improved model can consider the difference between the maximum and minimum principal stresses of the in-situ stress field and the pore pressure of the unconsolidated formation. We validated our numerical model with the angle of repose test, a benchmark problem for unconsolidated rocks. The validation results confirm the accuracy of our unconsolidated model. For the coupled model between the unconsolidated model and the flow model, we used an analytical solution to verify its reliability. Unconsolidated rock performances in an unconsolidated reservoir with fluid injection have been investigated based on our coupled model. The simulation results show that injection can activate the movement of unconsolidated rock particles, leading to changes in the distribution of effective stress and permeability. Our model has the potential to address large-scale unconsolidated rock issues and contribute to energy extraction.
{"title":"An Improved Continuum Approach for Unconsolidated Formations on the Field Scale","authors":"Bailong Liu, Takatoshi Ito","doi":"10.2118/219754-pa","DOIUrl":"https://doi.org/10.2118/219754-pa","url":null,"abstract":"\u0000 With the development of unconventional resources, such as oil sands and methane hydrate reservoirs, the importance of the mechanical performance model for underground unconsolidated rocks has increased significantly. The commonly used numerical approach for unconsolidated rocks is the discrete-element method (DEM). However, the extensive calculations required by the DEM make it inadequate for simulating unconsolidated rock behavior on a field scale. An alternative is the continuum approach, used to simulate the behavior of unconsolidated rocks on the field scale. In previous continuum approaches, unconsolidated rocks have been modeled as a visco-plastic fluid (i.e., Bingham fluid). The continuum approach based on visco-plastic fluid uses pressure (scalar) to describe the stress state of the particles. However, this approach does not account for the difference between the maximum and minimum principal stresses of the in-situ stress field when simulating the mechanical performance of unconsolidated rocks. Here, we developed an improved continuum approach for unconsolidated rocks and used the finite-element method as a numerical approach. Our improved model can consider the difference between the maximum and minimum principal stresses of the in-situ stress field and the pore pressure of the unconsolidated formation. We validated our numerical model with the angle of repose test, a benchmark problem for unconsolidated rocks. The validation results confirm the accuracy of our unconsolidated model. For the coupled model between the unconsolidated model and the flow model, we used an analytical solution to verify its reliability. Unconsolidated rock performances in an unconsolidated reservoir with fluid injection have been investigated based on our coupled model. The simulation results show that injection can activate the movement of unconsolidated rock particles, leading to changes in the distribution of effective stress and permeability. Our model has the potential to address large-scale unconsolidated rock issues and contribute to energy extraction.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140785252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Well cementing in areas close to the seabed remains a challenge due to unique conditions such as cold temperatures and weaker formations, leading to delayed cement hardening, extended drilling operation, and well integrity issues. Considering Portland cement’s limitations in cold areas and significant CO2 emissions through its manufacturing process, the need for more sustainable alternatives is highlighted. A low-density geopolymer through the water-extended approach was developed based on a previous study on low-temperature applications. Utilizing granite-based materials, this study optimizes the mix design by refining precursor particle sizes, using high-calcium blast furnace slag (BFS), and incorporating an amorphous potassium silicate activator. The research methodology includes sets of well cementing evaluations such as viscosity measurements, pumpability tests, and mechanical strength assessments. In addition, characterization techniques such as particle-size distribution (PSD) analysis, scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and isothermal calorimetry were used. These tests were crucial in understanding the material’s behavior under the specified application conditions. The findings reveal that the proposed geopolymer mix exhibits acceptable hardening time and mechanical strength development at lower temperatures, making it suitable for the challenging conditions of cold shallow-depth cementing. The study proves the feasibility of using high water content for geopolymers with acceptable properties and the novelty of its approach in the optimization of precursor particle sizes and the addition of higher calcium BFS. The geopolymer’s performance, even with a high water/solids ratio, highlights its versatility as a potential sustainable and efficient alternative to Portland cement.
{"title":"Water-Extended Low-Density Granite-Based Geopolymer for Low-Temperature Well Cementing Applications: The Impact of Precursor Selection and Particle-Size Distribution","authors":"M. N. Agista, F. Gomado, M. Khalifeh","doi":"10.2118/219760-pa","DOIUrl":"https://doi.org/10.2118/219760-pa","url":null,"abstract":"\u0000 Well cementing in areas close to the seabed remains a challenge due to unique conditions such as cold temperatures and weaker formations, leading to delayed cement hardening, extended drilling operation, and well integrity issues. Considering Portland cement’s limitations in cold areas and significant CO2 emissions through its manufacturing process, the need for more sustainable alternatives is highlighted. A low-density geopolymer through the water-extended approach was developed based on a previous study on low-temperature applications. Utilizing granite-based materials, this study optimizes the mix design by refining precursor particle sizes, using high-calcium blast furnace slag (BFS), and incorporating an amorphous potassium silicate activator. The research methodology includes sets of well cementing evaluations such as viscosity measurements, pumpability tests, and mechanical strength assessments. In addition, characterization techniques such as particle-size distribution (PSD) analysis, scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and isothermal calorimetry were used. These tests were crucial in understanding the material’s behavior under the specified application conditions. The findings reveal that the proposed geopolymer mix exhibits acceptable hardening time and mechanical strength development at lower temperatures, making it suitable for the challenging conditions of cold shallow-depth cementing. The study proves the feasibility of using high water content for geopolymers with acceptable properties and the novelty of its approach in the optimization of precursor particle sizes and the addition of higher calcium BFS. The geopolymer’s performance, even with a high water/solids ratio, highlights its versatility as a potential sustainable and efficient alternative to Portland cement.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140757161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. A. Mathews, Damir Kaishentayev, Nicolas Augsburger, Ryan Lefers, B. Hascakir
This research delves into the pioneering application of evaporative cooling (EC) to address the challenge of reducing total dissolved solids (TDS) in produced water generated during hydraulic fracturing operations in the Permian Basin. In this study, we used a meticulously designed laboratory-scale EC system comprising three cooling pads, a fan, a water reservoir, and a pump. Through a systematic series of experiments, both synthetic and authentic produced-water samples were treated, shedding light on the potential of this novel approach. The EC system efficiently processed untreated produced water, circulating it through the cooling pads, all while closely monitoring crucial variables such as inlet and outlet temperatures, relative humidity, and remaining water volume, utilizing a state-of-the-art temperature and humidity meter. Control experiments were systematically conducted to probe the influence of varying salinities, achieved by introducing NaCl into distilled water, encompassing a wide range from 0 ppm to 70,000 ppm. In addition, we extended our evaluation to real produced-water samples collected from diverse regions within the Permian Basin (Delaware, Northern Midland, and Southern Midland), reflecting the system’s capability to manage high salinity and the diverse impurities inherent to oil and gas production. A comparative analysis of energy consumption was undertaken, positioning EC against conventional thermal evaporation techniques. The findings revealed a compelling insight that differences in EC efficiency between synthetic and real oilfield brines were primarily attributed to the presence of sodium (Na+) and chlorine (Cl-) contents rather than the overall TDS concentration. Across all experiments, the system consistently achieved remarkable TDS removal efficiencies, hovering around the 100% mark for both synthetic and authentic produced-water samples. Moreover, the study unveiled a significant advantage of EC, as it proved to be significantly less energy-intensive when juxtaposed with conventional thermal evaporation methods. In addition, our experiments revealed that divalent ions like CaCl2 tend to lower the treatment efficiency compared to monovalent ions, adding a crucial dimension to our understanding of EC in water treatment. The EC system demonstrated remarkable efficiency, achieving nearly 100% TDS removal in both synthetic and real samples while being significantly less energy-intensive than conventional thermal evaporation methods. This research underscores EC’s potential as an effective, sustainable, and economical solution for high-TDS water treatment, with promising applications in industrial settings. The study also draws parallels between EC and air conditioning systems, suggesting its versatility in various industrial applications.
{"title":"Exploring Innovative Applications of Evaporative Cooling for High-Total-Dissolved-Solids Produced-Water Treatment","authors":"T. A. Mathews, Damir Kaishentayev, Nicolas Augsburger, Ryan Lefers, B. Hascakir","doi":"10.2118/214932-pa","DOIUrl":"https://doi.org/10.2118/214932-pa","url":null,"abstract":"\u0000 This research delves into the pioneering application of evaporative cooling (EC) to address the challenge of reducing total dissolved solids (TDS) in produced water generated during hydraulic fracturing operations in the Permian Basin. In this study, we used a meticulously designed laboratory-scale EC system comprising three cooling pads, a fan, a water reservoir, and a pump. Through a systematic series of experiments, both synthetic and authentic produced-water samples were treated, shedding light on the potential of this novel approach.\u0000 The EC system efficiently processed untreated produced water, circulating it through the cooling pads, all while closely monitoring crucial variables such as inlet and outlet temperatures, relative humidity, and remaining water volume, utilizing a state-of-the-art temperature and humidity meter. Control experiments were systematically conducted to probe the influence of varying salinities, achieved by introducing NaCl into distilled water, encompassing a wide range from 0 ppm to 70,000 ppm. In addition, we extended our evaluation to real produced-water samples collected from diverse regions within the Permian Basin (Delaware, Northern Midland, and Southern Midland), reflecting the system’s capability to manage high salinity and the diverse impurities inherent to oil and gas production. A comparative analysis of energy consumption was undertaken, positioning EC against conventional thermal evaporation techniques.\u0000 The findings revealed a compelling insight that differences in EC efficiency between synthetic and real oilfield brines were primarily attributed to the presence of sodium (Na+) and chlorine (Cl-) contents rather than the overall TDS concentration. Across all experiments, the system consistently achieved remarkable TDS removal efficiencies, hovering around the 100% mark for both synthetic and authentic produced-water samples. Moreover, the study unveiled a significant advantage of EC, as it proved to be significantly less energy-intensive when juxtaposed with conventional thermal evaporation methods. In addition, our experiments revealed that divalent ions like CaCl2 tend to lower the treatment efficiency compared to monovalent ions, adding a crucial dimension to our understanding of EC in water treatment.\u0000 The EC system demonstrated remarkable efficiency, achieving nearly 100% TDS removal in both synthetic and real samples while being significantly less energy-intensive than conventional thermal evaporation methods. This research underscores EC’s potential as an effective, sustainable, and economical solution for high-TDS water treatment, with promising applications in industrial settings. The study also draws parallels between EC and air conditioning systems, suggesting its versatility in various industrial applications.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140756980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nan Ma, Zhiyuan Wang, Jianbo Zhang, Peng Liu, Yudan Peng
Pipes with diameter reduction and direction variation are very common in deepwater extraction. While the high-pressure and low-temperature conditions may trigger severe hydrate problems, current studies on hydrate particle migration and deposition are mainly carried out in pipes with a constant diameter, whereas the law of diameter reduction has been less explored; in particular, the effect of diameter reduction + direction variation in pipe has not been reported. In this study, a model of hydrate particle migration and deposition in special pipelines is established based on the computational fluid dynamics (CFD)-discrete element solver (DEM)-application programming interface (API) method, which can be used to carry out real-time visualization calculations of hydrate particles. Simultaneously, this paper reveals the mechanism of hydrate particle migration and deposition at the diameter reduction and direction variation, which provides a new idea for the design of the pipe. Furthermore, for the pipe with diameter reduction + direction variation, the entire process of deposition blockage is simulated, and dangerous locations of pipe clogging are identified. The simulation results found that there is a maximum hydrate deposition particle diameter (MHDPD) for hydrate deposition in the pipe. The results of this work may provide valuable references for accurate prediction of particle deposition in deepwater development.
{"title":"Simulation of Hydrate Migration and Deposition in Pipe with Diameter Reduction and Direction Variation","authors":"Nan Ma, Zhiyuan Wang, Jianbo Zhang, Peng Liu, Yudan Peng","doi":"10.2118/219756-pa","DOIUrl":"https://doi.org/10.2118/219756-pa","url":null,"abstract":"\u0000 Pipes with diameter reduction and direction variation are very common in deepwater extraction. While the high-pressure and low-temperature conditions may trigger severe hydrate problems, current studies on hydrate particle migration and deposition are mainly carried out in pipes with a constant diameter, whereas the law of diameter reduction has been less explored; in particular, the effect of diameter reduction + direction variation in pipe has not been reported. In this study, a model of hydrate particle migration and deposition in special pipelines is established based on the computational fluid dynamics (CFD)-discrete element solver (DEM)-application programming interface (API) method, which can be used to carry out real-time visualization calculations of hydrate particles. Simultaneously, this paper reveals the mechanism of hydrate particle migration and deposition at the diameter reduction and direction variation, which provides a new idea for the design of the pipe. Furthermore, for the pipe with diameter reduction + direction variation, the entire process of deposition blockage is simulated, and dangerous locations of pipe clogging are identified. The simulation results found that there is a maximum hydrate deposition particle diameter (MHDPD) for hydrate deposition in the pipe. The results of this work may provide valuable references for accurate prediction of particle deposition in deepwater development.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140780826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. N. Lima, H. J. Skadsem, F. R. Souza, Takuma Kaneshima, S. Letichevsky, R. D. de Avillez, Flavio A. Silva
Limiting the fluid loss from the cement slurry to the adjacent formation by using additives is essential for maintaining the slurry’s water/cement ratio. The present work focuses on the effect of noncrosslinked polyvinyl alcohol additive (PVOH), a widely used fluid loss additive (FLA), on the compression strength and rheological behavior of Class G cement pastes. Results of the current study show that the PVOH surfactant characteristic and its absorptive mechanism interfere not only with the hydration process but also with the physical properties and compressive strength of cement pastes, such as porosity, permeability, and early age strength, which revealed the importance of using a defoamer when PVOH is present in the mixture. In the absence of a defoamer, the PVOH additive generates foam in the mixed cement paste samples, which results in increased porosity and reduced compressive strength of the hardened cement paste. Moreover, regarding rheology, increasing the PVOH concentration increased the effective viscosity when evaluating flow curves. Therefore, this study demonstrates a systematic method for assessing the possible effects of cement paste additives, such as PVOH and defoamer, providing a physical and mechanical approach rather than just chemical to evaluate additives’ influence on the mixtures. This method should consider different additives in combination with PVOH to test cement paste stability and to obtain specific working recipes.
{"title":"Effects of Noncrosslinked Polyvinyl Alcohol Fluid Loss Additive on the Compressive Strength and Viscosity of Class G Cement Slurries","authors":"V. N. Lima, H. J. Skadsem, F. R. Souza, Takuma Kaneshima, S. Letichevsky, R. D. de Avillez, Flavio A. Silva","doi":"10.2118/219755-pa","DOIUrl":"https://doi.org/10.2118/219755-pa","url":null,"abstract":"\u0000 Limiting the fluid loss from the cement slurry to the adjacent formation by using additives is essential for maintaining the slurry’s water/cement ratio. The present work focuses on the effect of noncrosslinked polyvinyl alcohol additive (PVOH), a widely used fluid loss additive (FLA), on the compression strength and rheological behavior of Class G cement pastes. Results of the current study show that the PVOH surfactant characteristic and its absorptive mechanism interfere not only with the hydration process but also with the physical properties and compressive strength of cement pastes, such as porosity, permeability, and early age strength, which revealed the importance of using a defoamer when PVOH is present in the mixture. In the absence of a defoamer, the PVOH additive generates foam in the mixed cement paste samples, which results in increased porosity and reduced compressive strength of the hardened cement paste. Moreover, regarding rheology, increasing the PVOH concentration increased the effective viscosity when evaluating flow curves. Therefore, this study demonstrates a systematic method for assessing the possible effects of cement paste additives, such as PVOH and defoamer, providing a physical and mechanical approach rather than just chemical to evaluate additives’ influence on the mixtures. This method should consider different additives in combination with PVOH to test cement paste stability and to obtain specific working recipes.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140778572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
China’s coalbed methane (CBM) reservoirs are characterized by low permeability (<1 md). Stimulation with conventional acids is facing the problems of secondary precipitation, high corrosion rates, and fines migration. Chelating agent intrusion was proposed as a promising alternative for conventional acids, while the pore structure evolution induced by it needs to be further clarified. In this study, coal samples with three different ranks were selected and treated with L-glutamic acid N, N-diacetic acid (GLDA). Low-temperature Ar and N2 adsorption tests, mercury intrusion porosimetry (MIP), and scanning electron microscope (SEM) analyses were applied to investigate nanoscale to macroscale pore structure changes. X-ray fluorescence (XRF) spectroscopy tests were conducted to determine the mineralogical change of coal. The results show that chelating agent intrusion can widen fracture width, connect micropores, and create void space in macropores by dissolving carbonate minerals, while the nanoscale pore volumes (PVs) showed a slight decrease due to clay minerals collapse. The fractal dimensions Dm calculated by the MIP results of lignite, bituminous coal, and anthracite coal decreased by 0.2735, 0.1734, and 0.1444, respectively. It is indicated that a pore structure with a diameter of >100 nm of the coal became more unified, which favors the seepage of gas/water. The chelating agent intrusion shows a significant effect on lignite, followed by bituminous and anthracite coal. However, the metal element reduction rate of anthracite coal presents the highest, followed by bituminous coal and lignite. There can be a risk that a long intrusion time would loosen the skeleton of lignite, leading to further reservoir damage. Therefore, bituminous and anthracite coal samples are preferred, as the skeletons of higher-rank coals are more compact. These research findings introduced a potential stimulation method for enhancing CBM recovery and provided references for field application.
{"title":"Multiscale Pore Structure Evolution of Different Rank Coals Induced by Chelating Agent Intrusion","authors":"Shuya Chen, Zheng Dang, Chuanjie Deng, Zexin Chen, Shuhao Tan, Xianyu Yang, Jihua Cai, Zhangxin Chen","doi":"10.2118/219758-pa","DOIUrl":"https://doi.org/10.2118/219758-pa","url":null,"abstract":"\u0000 China’s coalbed methane (CBM) reservoirs are characterized by low permeability (<1 md). Stimulation with conventional acids is facing the problems of secondary precipitation, high corrosion rates, and fines migration. Chelating agent intrusion was proposed as a promising alternative for conventional acids, while the pore structure evolution induced by it needs to be further clarified. In this study, coal samples with three different ranks were selected and treated with L-glutamic acid N, N-diacetic acid (GLDA). Low-temperature Ar and N2 adsorption tests, mercury intrusion porosimetry (MIP), and scanning electron microscope (SEM) analyses were applied to investigate nanoscale to macroscale pore structure changes. X-ray fluorescence (XRF) spectroscopy tests were conducted to determine the mineralogical change of coal. The results show that chelating agent intrusion can widen fracture width, connect micropores, and create void space in macropores by dissolving carbonate minerals, while the nanoscale pore volumes (PVs) showed a slight decrease due to clay minerals collapse. The fractal dimensions Dm calculated by the MIP results of lignite, bituminous coal, and anthracite coal decreased by 0.2735, 0.1734, and 0.1444, respectively. It is indicated that a pore structure with a diameter of >100 nm of the coal became more unified, which favors the seepage of gas/water. The chelating agent intrusion shows a significant effect on lignite, followed by bituminous and anthracite coal. However, the metal element reduction rate of anthracite coal presents the highest, followed by bituminous coal and lignite. There can be a risk that a long intrusion time would loosen the skeleton of lignite, leading to further reservoir damage. Therefore, bituminous and anthracite coal samples are preferred, as the skeletons of higher-rank coals are more compact. These research findings introduced a potential stimulation method for enhancing CBM recovery and provided references for field application.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140771081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Interwell interference is the superposition effect of coalbed methane (CBM) reservoir pressure. This study aims to provide a new direction for the quantitative analysis of interwell interference from the hydrogeochemical characteristics of produced water from CBM wells. A total of 24 produced water samples collected from the Panhe (PH) group, Shizhuangnan (SZN)-1 group, and SZN-2 group in Qinshui Basin were selected for the comparative analysis. The water type of all water samples is characterized by Na-HCO3, with Na+ being the main total dissolved solids (TDS) provider. The self-similar major ionic characteristics of the PH and SZN-2 groups are prone to the occurrence of interwell interference. The δD and δ18O show that the main source of produced water is atmospheric circulating water. The similar isotope characteristics of produced water in the PH and SZN-2 groups represent that there is remarkable interwell interference. Sr, As, Cu, Ga, Li, Rb, Sn, Mo, and V are selected as indicator elements. In the cluster analysis, all CBM wells form a single cluster in the PH and SZN-2 groups in the first three iterations, indicating interwell interference. According to the established fuzzy discriminative model, interwell interference is divided into two types—strong interwell interference and weak interwell interference. Most CBM wells in the PH and SZN-2 groups show strong interwell interference. This study can provide theoretical foundations for the dynamic pressure regulation and well pattern infilling of CBM wells.
{"title":"Identification of Interwell Interference Based on Hydrogeochemical Characteristics of Produced Water from Coalbed Methane Wells: A Case Study in the Southern Qinshui Basin, China","authors":"Mingkai Tu, Xiaoming Wang, Shihui Hou, Wenwen Chen, Zheng-Jie Dang","doi":"10.2118/219759-pa","DOIUrl":"https://doi.org/10.2118/219759-pa","url":null,"abstract":"\u0000 Interwell interference is the superposition effect of coalbed methane (CBM) reservoir pressure. This study aims to provide a new direction for the quantitative analysis of interwell interference from the hydrogeochemical characteristics of produced water from CBM wells. A total of 24 produced water samples collected from the Panhe (PH) group, Shizhuangnan (SZN)-1 group, and SZN-2 group in Qinshui Basin were selected for the comparative analysis. The water type of all water samples is characterized by Na-HCO3, with Na+ being the main total dissolved solids (TDS) provider. The self-similar major ionic characteristics of the PH and SZN-2 groups are prone to the occurrence of interwell interference. The δD and δ18O show that the main source of produced water is atmospheric circulating water. The similar isotope characteristics of produced water in the PH and SZN-2 groups represent that there is remarkable interwell interference. Sr, As, Cu, Ga, Li, Rb, Sn, Mo, and V are selected as indicator elements. In the cluster analysis, all CBM wells form a single cluster in the PH and SZN-2 groups in the first three iterations, indicating interwell interference. According to the established fuzzy discriminative model, interwell interference is divided into two types—strong interwell interference and weak interwell interference. Most CBM wells in the PH and SZN-2 groups show strong interwell interference. This study can provide theoretical foundations for the dynamic pressure regulation and well pattern infilling of CBM wells.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140796100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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