Wettability is a key factor influencing oil production, particularly from the oil-wet carbonate reservoirs where the recoveries are often low. This is a serious problem for the oil industry as significant portion of the world's hydrocarbon reserves resides in carbonate formations. Since the wettability has its roots in the inter-molecular interactions between the oil and the mineral, our objectives are, first, to provide the molecular-level understanding of the carbonate wettability and, second, to apply this understanding to devise effective approaches for wettability alteration. Specifically, we focused on chemical additives such as surfactants and ions, which have demonstrated potential as wettability reversal agents. Molecular dynamics (MD) simulations were used as the primary method to study the wettability properties on newly-developed model calcite and dolomite surfaces that mimic experimentally-known mineral properties. Wettability reversal by cationic, anionic, and non-ionic surfactants, as well as by divalent ions (Ca2+, Mg2+, and SO42-) were investigated. A systematic approach for maximizing the surfactant efficiency by tuning the cationic surfactant head-group chemistry was proposed. To validate the MD simulation results, experimental contact angle measurements on dolomite chips were conducted. The MD simulation results demonstrated that, in the absence of asphaltenes, the oil-wetness of the carbonate minerals arises from the electrostatic attraction between the (negatively charged) oil carboxylates and the (positive) surfaces. Due to this electrostatic nature, the wettability could be reversed only by the cationic (positive) surfactants, which screen the oil-surface attraction. Other surfactant types had negligible effect, in agreement with the experimental contact angle measurements. Moreover, the wettability alteration efficiency of the cationic surfactants was directly related to their molecular charge distributions, offering guidelines for the practical design of the most potent wettability-reversing molecules. The simulations of the wettability alteration by Mg2+, Ca2+, and SO42- ions were likewise consistent with the contact angle measurements. The roles of individual ions in the multiple ion exchange (MIE) mechanism were deduced, and the known strong temperature dependence of their wettability alteration effect explained by the stability of the ion hydration shells. Finally, the simulations also exposed differences between the wettability reversal mechanisms on calcite and dolomite minerals, which may have important practical impact. Our results offer a novel perspective on the carbonate wettability and its reversal from the standpoint of atomic-level interactions and molecular mechanisms. New models for the carbonate surfaces were developed for reliable simulations of the wetting properties, which led to new insights into the origins of carbonate oil-wetness and the mechanisms of its reversal in two types of minerals. La
{"title":"Toward the Rational Design of Chemical Formulations for EOR from Carbonates: Molecular–Level Understanding of Carbonate Wettability and its Reversal by Surfactants and Ions","authors":"Shixun Bai, J. Kubelka, M. Piri","doi":"10.2118/207340-ms","DOIUrl":"https://doi.org/10.2118/207340-ms","url":null,"abstract":"\u0000 Wettability is a key factor influencing oil production, particularly from the oil-wet carbonate reservoirs where the recoveries are often low. This is a serious problem for the oil industry as significant portion of the world's hydrocarbon reserves resides in carbonate formations. Since the wettability has its roots in the inter-molecular interactions between the oil and the mineral, our objectives are, first, to provide the molecular-level understanding of the carbonate wettability and, second, to apply this understanding to devise effective approaches for wettability alteration. Specifically, we focused on chemical additives such as surfactants and ions, which have demonstrated potential as wettability reversal agents.\u0000 Molecular dynamics (MD) simulations were used as the primary method to study the wettability properties on newly-developed model calcite and dolomite surfaces that mimic experimentally-known mineral properties. Wettability reversal by cationic, anionic, and non-ionic surfactants, as well as by divalent ions (Ca2+, Mg2+, and SO42-) were investigated. A systematic approach for maximizing the surfactant efficiency by tuning the cationic surfactant head-group chemistry was proposed. To validate the MD simulation results, experimental contact angle measurements on dolomite chips were conducted.\u0000 The MD simulation results demonstrated that, in the absence of asphaltenes, the oil-wetness of the carbonate minerals arises from the electrostatic attraction between the (negatively charged) oil carboxylates and the (positive) surfaces. Due to this electrostatic nature, the wettability could be reversed only by the cationic (positive) surfactants, which screen the oil-surface attraction. Other surfactant types had negligible effect, in agreement with the experimental contact angle measurements. Moreover, the wettability alteration efficiency of the cationic surfactants was directly related to their molecular charge distributions, offering guidelines for the practical design of the most potent wettability-reversing molecules. The simulations of the wettability alteration by Mg2+, Ca2+, and SO42- ions were likewise consistent with the contact angle measurements. The roles of individual ions in the multiple ion exchange (MIE) mechanism were deduced, and the known strong temperature dependence of their wettability alteration effect explained by the stability of the ion hydration shells. Finally, the simulations also exposed differences between the wettability reversal mechanisms on calcite and dolomite minerals, which may have important practical impact.\u0000 Our results offer a novel perspective on the carbonate wettability and its reversal from the standpoint of atomic-level interactions and molecular mechanisms. New models for the carbonate surfaces were developed for reliable simulations of the wetting properties, which led to new insights into the origins of carbonate oil-wetness and the mechanisms of its reversal in two types of minerals. La","PeriodicalId":10981,"journal":{"name":"Day 4 Thu, November 18, 2021","volume":"248 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77285670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Z. Ahmad, Abdullah Alhaj Al Hosini, Mohammed Ibrahim Al Janahi, Abdulla Mohammed Al Marzouqi, M. A. Siddiqui, Abdulla Haidar Abdulla Al Zarouni, Saad Ansari
Well killing always remains a most radical part during the life cycle of gas production wells with reservoir and completion integrity issues. In moderate permeability gas reservoirs, it will be more challenging due to below issues; Low pressure gas reservoir with moderate reservoir permeability where hydrostatic head of water is almost double the formation pressure Well with the sustainable annulus pressures (Production & first cemented annulus) Well with complex layered scale / asphalting deposition Completion jewelry component integrity breached Recycle reservoir with pressure maintenance Noise logs / corrosion logs generally conducted in order to assess the downhole completion jewelry and potential leak source prior any attempt for killing the well. To achieve the desired accessibility extensive scale analysis for better designing of scale clean out operation carried out specially to access the SPM. Variation of reservoir permeability considered for designing of optimized kill fluid for Depleted horizontal gas reservoir to cater challenge of complete losses. Effective fluid loss solutions designed and implemented to avoid abnormal fluid losses. Further more Polymer based gels used to kill and prevent the gas peculation to surface. Wells having completion and reservoir integrity issue isolated by considering cement zonal isolation, salt plugs, thru-tubing bridge plugs and nipple less plugs. All these barriers having their advantages and disadvantages with reference to work over objectives and their application limitations with respect to well conditions and detail study conducted for each candidate prior execution. Depletion Gas well killing and securing operation considered to be complex in nature and may result serious concern of rig intervention or well future objectives in case of improper execution. Gas wells having reservoir integrity issues and in case of 1st cemented Annulus pressure can be isolated by using thru-tubing bridge plugs. For retrieval of dummy from SPM must be done after setting of downhole plug to avoid any heavy suction for wire line operation. Cement plug operation is not suitable for such wells due to severe losses and fluid circulation limitation. Adequate selection of kill gel fluid as per reservoir characteristics will improve the killing efficiency.
{"title":"Challenges of Gas Wells Killing Operation with Emphasis on Reservoir & Completion Integrity Issues","authors":"Z. Ahmad, Abdullah Alhaj Al Hosini, Mohammed Ibrahim Al Janahi, Abdulla Mohammed Al Marzouqi, M. A. Siddiqui, Abdulla Haidar Abdulla Al Zarouni, Saad Ansari","doi":"10.2118/208063-ms","DOIUrl":"https://doi.org/10.2118/208063-ms","url":null,"abstract":"\u0000 Well killing always remains a most radical part during the life cycle of gas production wells with reservoir and completion integrity issues. In moderate permeability gas reservoirs, it will be more challenging due to below issues;\u0000 Low pressure gas reservoir with moderate reservoir permeability where hydrostatic head of water is almost double the formation pressure\u0000 Well with the sustainable annulus pressures (Production & first cemented annulus) Well with complex layered scale / asphalting deposition Completion jewelry component integrity breached Recycle reservoir with pressure maintenance\u0000 Noise logs / corrosion logs generally conducted in order to assess the downhole completion jewelry and potential leak source prior any attempt for killing the well. To achieve the desired accessibility extensive scale analysis for better designing of scale clean out operation carried out specially to access the SPM. Variation of reservoir permeability considered for designing of optimized kill fluid for Depleted horizontal gas reservoir to cater challenge of complete losses. Effective fluid loss solutions designed and implemented to avoid abnormal fluid losses. Further more Polymer based gels used to kill and prevent the gas peculation to surface.\u0000 Wells having completion and reservoir integrity issue isolated by considering cement zonal isolation, salt plugs, thru-tubing bridge plugs and nipple less plugs. All these barriers having their advantages and disadvantages with reference to work over objectives and their application limitations with respect to well conditions and detail study conducted for each candidate prior execution.\u0000 Depletion Gas well killing and securing operation considered to be complex in nature and may result serious concern of rig intervention or well future objectives in case of improper execution. Gas wells having reservoir integrity issues and in case of 1st cemented Annulus pressure can be isolated by using thru-tubing bridge plugs. For retrieval of dummy from SPM must be done after setting of downhole plug to avoid any heavy suction for wire line operation. Cement plug operation is not suitable for such wells due to severe losses and fluid circulation limitation. Adequate selection of kill gel fluid as per reservoir characteristics will improve the killing efficiency.","PeriodicalId":10981,"journal":{"name":"Day 4 Thu, November 18, 2021","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78918517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Raja Srinivasa Rao Mohan Aita, T. Omar, A. Sarkar, M. Roy, Xing Sun, Rachel Lunn, Huan Wu
Recently the old accommodation platform (OAP) was decommissioned in Offshore Abu Dhabi. This platform was founded on four legs with piles inside and duly grouted inside pile and annulus. The main objective of this to carry out bond strength tests and finite element (FE) analysis for retrieved OAP grouted samples to investigate if any ageing effect on the bond strength of the grouted pile/sleeve connections for aged offshore structures. Nine Sleeve/Pile samples of varying lengths from 240mm to 1200mm were extracted for testing from the decommissioned platform. Dimensional analysis was carried out to assess the thickness loss and eccentricity. A bespoke testing rig with the maximum load capacity of 15,000kN was built at TWI Ltd. to perform bond strength tests. Finite element (FE) simulation of the testing was carried out and compared to the test results to calibrate and fine-tune material constitutive behaviour parameters and interfacial (friction and bond) parameters. Specimen measurements revealed a significant scatter in annulus grout thicknesses of various sleeve/pile specimens with maximum variations of up to 52%. These results indicate that pile alignment is strongly variable. Shear keys in the form of steel rings welded alternately onto the leg's inner surface and the pile outer surface providing mechanical resistance to relative sliding of the grout between the two bodies. The testing results shown that the ultimate loads varied significantly among various specimens, ranged between 9920kN for 1m specimen and 1800kN for 1.2m specimen. FE simulations agreed well with the observed failure modes and were used to investigate how the measured failure loads were influenced by grout material properties, cohesive bond behaviour and geometrical parameters such as shear keys and eccentricity. From the FE studies, it was found that different cohesive (surface) parameters are required to give the best fit, with the higher cohesive stiffness and strength associated with a higher failure load. Grout strength is also a significant parameter, but the effect of surface cohesion is less significant compared to material strength. The majority of the tested values were found to be meeting the minimum bond strength resulting from available standards (eg. ISO 19902). This type of real time testing output will provide insight into various parameters that contribute to bond strength in pile leg grouted connections. Moreover, these test and assessment results will form an integral and important input to various ongoing researches associated with ADNOC's grouted connections being carried out as part of another JIP led by National University of Singapore which is aimed at deriving design equations applicable to grouted connections beyond codal limits.
{"title":"Bond Strength Testing and Simulation for Grouted Pile/sleeve Connections in Aged Structures","authors":"Raja Srinivasa Rao Mohan Aita, T. Omar, A. Sarkar, M. Roy, Xing Sun, Rachel Lunn, Huan Wu","doi":"10.2118/207870-ms","DOIUrl":"https://doi.org/10.2118/207870-ms","url":null,"abstract":"\u0000 Recently the old accommodation platform (OAP) was decommissioned in Offshore Abu Dhabi. This platform was founded on four legs with piles inside and duly grouted inside pile and annulus. The main objective of this to carry out bond strength tests and finite element (FE) analysis for retrieved OAP grouted samples to investigate if any ageing effect on the bond strength of the grouted pile/sleeve connections for aged offshore structures. Nine Sleeve/Pile samples of varying lengths from 240mm to 1200mm were extracted for testing from the decommissioned platform. Dimensional analysis was carried out to assess the thickness loss and eccentricity. A bespoke testing rig with the maximum load capacity of 15,000kN was built at TWI Ltd. to perform bond strength tests. Finite element (FE) simulation of the testing was carried out and compared to the test results to calibrate and fine-tune material constitutive behaviour parameters and interfacial (friction and bond) parameters. Specimen measurements revealed a significant scatter in annulus grout thicknesses of various sleeve/pile specimens with maximum variations of up to 52%. These results indicate that pile alignment is strongly variable. Shear keys in the form of steel rings welded alternately onto the leg's inner surface and the pile outer surface providing mechanical resistance to relative sliding of the grout between the two bodies. The testing results shown that the ultimate loads varied significantly among various specimens, ranged between 9920kN for 1m specimen and 1800kN for 1.2m specimen. FE simulations agreed well with the observed failure modes and were used to investigate how the measured failure loads were influenced by grout material properties, cohesive bond behaviour and geometrical parameters such as shear keys and eccentricity. From the FE studies, it was found that different cohesive (surface) parameters are required to give the best fit, with the higher cohesive stiffness and strength associated with a higher failure load. Grout strength is also a significant parameter, but the effect of surface cohesion is less significant compared to material strength. The majority of the tested values were found to be meeting the minimum bond strength resulting from available standards (eg. ISO 19902). This type of real time testing output will provide insight into various parameters that contribute to bond strength in pile leg grouted connections. Moreover, these test and assessment results will form an integral and important input to various ongoing researches associated with ADNOC's grouted connections being carried out as part of another JIP led by National University of Singapore which is aimed at deriving design equations applicable to grouted connections beyond codal limits.","PeriodicalId":10981,"journal":{"name":"Day 4 Thu, November 18, 2021","volume":"46 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83061106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Bourgeois, Hocine Berrahmoun, Maryam Mohamed Al Attar, Djilali Boulenouar, Djelloul Hammadi, C. Romero, Wen Shi, Maria Fernanda Torrez
This paper is based on the analysis of miscible WAG for an onshore Middle-East field, with strongly undersaturated light oil. Water Alternate Gas operations have been ongoing for around 5 years, which is relatively recent compared to more than 40 years of production history. Goal of this work was to assess the efficiency of this miscible hydrocarbon WAG and to optimize it on the different compartments, with respect to miscibility, voidage replacement, and recycling. As this is a large mature field, with WAG operations dispatched on around 50 injectors and 9 fault blocks (compartments), the method of analysis had to be robust with respect to the different injection strategies followed in the past. It was essentially based on injection and production data, but also used pressure data when available. We computed the following dimensionless variables: oil recovery factor, BSW, voidage replacement ratio (VRR), and also WAG ratio and gas recycling ratio (GRR). Their evolution versus time was analyzed and compared between fault blocks. Using dimensionless variables allowed to compare fault blocks with different initial volumes in place, and to illustrate trends versus time. It was also found beneficial to lump some compartments, when communication was substantiated by pressure data. On the production side, we used the conventional BSW and GOR variables to quantify the water and gas recycling ratio. On the injection side, we observed that in some compartments, the historical WAG ratio was too low in the oil zone, which could be quantified by excluding the peripheral water injection volumes. The analysis allowed also to estimate the gas utilization factor and efficiency, which confirmed the overall high efficiency of miscible gas injection in 3-phase mode. It was also found that the injected fluid efficiency correlated with geology: gas injection tends to be more efficient in zones with high permeabilities at the bottom (coarsening downwards), while water injection is better adapted to zones with high permeabilities at the top (coarsening upwards). Estimating these water and gas efficiencies also allowed to optimize the injection strategy on a field level, by comparing the water efficiency with other units of the field only under waterflood.
{"title":"Miscible WAG Efficiency Assessment on a Large Mature Carbonate Field","authors":"M. Bourgeois, Hocine Berrahmoun, Maryam Mohamed Al Attar, Djilali Boulenouar, Djelloul Hammadi, C. Romero, Wen Shi, Maria Fernanda Torrez","doi":"10.2118/207384-ms","DOIUrl":"https://doi.org/10.2118/207384-ms","url":null,"abstract":"\u0000 This paper is based on the analysis of miscible WAG for an onshore Middle-East field, with strongly undersaturated light oil. Water Alternate Gas operations have been ongoing for around 5 years, which is relatively recent compared to more than 40 years of production history. Goal of this work was to assess the efficiency of this miscible hydrocarbon WAG and to optimize it on the different compartments, with respect to miscibility, voidage replacement, and recycling.\u0000 As this is a large mature field, with WAG operations dispatched on around 50 injectors and 9 fault blocks (compartments), the method of analysis had to be robust with respect to the different injection strategies followed in the past. It was essentially based on injection and production data, but also used pressure data when available. We computed the following dimensionless variables: oil recovery factor, BSW, voidage replacement ratio (VRR), and also WAG ratio and gas recycling ratio (GRR). Their evolution versus time was analyzed and compared between fault blocks.\u0000 Using dimensionless variables allowed to compare fault blocks with different initial volumes in place, and to illustrate trends versus time. It was also found beneficial to lump some compartments, when communication was substantiated by pressure data. On the production side, we used the conventional BSW and GOR variables to quantify the water and gas recycling ratio. On the injection side, we observed that in some compartments, the historical WAG ratio was too low in the oil zone, which could be quantified by excluding the peripheral water injection volumes.\u0000 The analysis allowed also to estimate the gas utilization factor and efficiency, which confirmed the overall high efficiency of miscible gas injection in 3-phase mode. It was also found that the injected fluid efficiency correlated with geology: gas injection tends to be more efficient in zones with high permeabilities at the bottom (coarsening downwards), while water injection is better adapted to zones with high permeabilities at the top (coarsening upwards). Estimating these water and gas efficiencies also allowed to optimize the injection strategy on a field level, by comparing the water efficiency with other units of the field only under waterflood.","PeriodicalId":10981,"journal":{"name":"Day 4 Thu, November 18, 2021","volume":"74 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75933938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Gomez, Marcelo Robles, Cristian Di Giuseppe, F. Galliano, Jeronimo Centineo, Fernando Medda, Carlos Mario Calad Serrano, Sebastian Plotno, P. Sarma, F. Gutiérrez
This paper presents the process and results of the application of Data Physics to optimize production of a mature field in the Gulf of San Jorge Basin in Argentina. Data Physics is a novel technology that blends the reservoir physics (black oil) used in traditional numerical simulation with machine learning and advanced optimization techniques. Data Physics was described in detail in a prior paper (Sarma, et al SPE-185507-MS) as a physics-based modeling approach augmented by machine learning. In essence, historical production and injection data are assimilated using an Ensemble Kalman Filter (EnKF) to infer the petrophysical parameters and create a predictive model of the field. This model is then used with Evolutionary Algorithms (EA) to find the pareto front for multiple optimization objectives like production, injection and NPV. Ultimately, the main objective of Data Physics is to enable Closed Loop Optimization. The technology was applied on a small section of a very large field in the Gulf of San Jorge comprised of 134 wells including 83 active producers and 27 active water injectors; up to 12 mandrels per well are used to provide with selective injection, while production is carried out in a comingled manner. Production zonal allocation is calculated using an in-house process based on swabbing tests and recovery factors and is used as input to the Data Physics application, while injection allocation is based on tracer logs performed in each injection well twice a year. This paper describes the modeling and optimization phases as well as the implementation in the field and the results obtained after performing two close loop optimization cycles. The initial model was developed between October and December 2018 and initial field implementation took place between January to March 2019. A second optimization cycle was then executed in January 2020 and results observed for several months.
{"title":"Application of a Combination of Machine Learning and Reservoir Physics to Increase Production in a Mature Waterflood Field in the San Jorge Basin in Argentina","authors":"J. Gomez, Marcelo Robles, Cristian Di Giuseppe, F. Galliano, Jeronimo Centineo, Fernando Medda, Carlos Mario Calad Serrano, Sebastian Plotno, P. Sarma, F. Gutiérrez","doi":"10.2118/207897-ms","DOIUrl":"https://doi.org/10.2118/207897-ms","url":null,"abstract":"\u0000 This paper presents the process and results of the application of Data Physics to optimize production of a mature field in the Gulf of San Jorge Basin in Argentina. Data Physics is a novel technology that blends the reservoir physics (black oil) used in traditional numerical simulation with machine learning and advanced optimization techniques. Data Physics was described in detail in a prior paper (Sarma, et al SPE-185507-MS) as a physics-based modeling approach augmented by machine learning. In essence, historical production and injection data are assimilated using an Ensemble Kalman Filter (EnKF) to infer the petrophysical parameters and create a predictive model of the field. This model is then used with Evolutionary Algorithms (EA) to find the pareto front for multiple optimization objectives like production, injection and NPV. Ultimately, the main objective of Data Physics is to enable Closed Loop Optimization.\u0000 The technology was applied on a small section of a very large field in the Gulf of San Jorge comprised of 134 wells including 83 active producers and 27 active water injectors; up to 12 mandrels per well are used to provide with selective injection, while production is carried out in a comingled manner. Production zonal allocation is calculated using an in-house process based on swabbing tests and recovery factors and is used as input to the Data Physics application, while injection allocation is based on tracer logs performed in each injection well twice a year.\u0000 This paper describes the modeling and optimization phases as well as the implementation in the field and the results obtained after performing two close loop optimization cycles. The initial model was developed between October and December 2018 and initial field implementation took place between January to March 2019. A second optimization cycle was then executed in January 2020 and results observed for several months.","PeriodicalId":10981,"journal":{"name":"Day 4 Thu, November 18, 2021","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75141130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Bayerl, P. Neff, T. Clemens, M. Sieberer, B. Stummer, A. Zamolyi
Field re-development planning for tertiary recovery projects in mature fields traditionally involves a comprehensive subsurface evaluation circle, including static/dynamic modeling, scenario assessment and candidate selection based on economic models. The aforementioned sequential approach is time-consuming and includes the risk of delaying project maturation. This work introduces a novel approach which integrates subsurface geological and dynamic modeling as well as economics and uses machine learning augmented uncertainty workflows to achieve project acceleration. In the elaborated enhanced oil recovery (EOR) evaluation process, a machine learning assisted approach is used in order to narrow geological and dynamic parameter ranges both for model initialization and subsequent history matching. The resulting posterior parameter distributions are used to create the input models for scenario evaluation under uncertainty. This scenario screening comprises not only an investigation of qualified EOR roll-out areas, but also includes detailed engineering such as well spacing optimization and pattern generation. Eventually, a fully stochastic economic evaluation approach is performed in order to rank and select scenarios for EOR implementation. The presented workflow has been applied successfully for a mature oil field in Central/Eastern Europe with 60+ years of production history. It is shown that by using a fully stochastic approach, integrating subsurface engineering and economic evaluation, a considerable acceleration of up to 75% in project maturation time is achieved. Moreover, the applied workflow stands out due to its flexibility and adaptability based on changes in the project scope. In the course of this case study, a sector roll-out of chemical EOR is elaborated, including a proposal for 27 new well candidates and 17 well conversions, resulting in an incremental oil production of 4.7MM bbl. The key findings were: A workflow is introduced that delivers a fully stochastic economic evaluation while honoring the input and measured data.The delivered scenarios are conditioned to the geological information and the production history in a Bayesian Framework to ensure full consistency of the selected subsurface model advanced to forecasting.The applied process results in substantial time reduction for an EOR re-development project evaluation cycle.
{"title":"Accelerating Mature Field EOR Evaluation Using Machine Learning Uncertainty Workflows Integrating Subsurface And Economics","authors":"M. Bayerl, P. Neff, T. Clemens, M. Sieberer, B. Stummer, A. Zamolyi","doi":"10.2118/208194-ms","DOIUrl":"https://doi.org/10.2118/208194-ms","url":null,"abstract":"\u0000 Field re-development planning for tertiary recovery projects in mature fields traditionally involves a comprehensive subsurface evaluation circle, including static/dynamic modeling, scenario assessment and candidate selection based on economic models. The aforementioned sequential approach is time-consuming and includes the risk of delaying project maturation. This work introduces a novel approach which integrates subsurface geological and dynamic modeling as well as economics and uses machine learning augmented uncertainty workflows to achieve project acceleration.\u0000 In the elaborated enhanced oil recovery (EOR) evaluation process, a machine learning assisted approach is used in order to narrow geological and dynamic parameter ranges both for model initialization and subsequent history matching. The resulting posterior parameter distributions are used to create the input models for scenario evaluation under uncertainty. This scenario screening comprises not only an investigation of qualified EOR roll-out areas, but also includes detailed engineering such as well spacing optimization and pattern generation. Eventually, a fully stochastic economic evaluation approach is performed in order to rank and select scenarios for EOR implementation.\u0000 The presented workflow has been applied successfully for a mature oil field in Central/Eastern Europe with 60+ years of production history. It is shown that by using a fully stochastic approach, integrating subsurface engineering and economic evaluation, a considerable acceleration of up to 75% in project maturation time is achieved. Moreover, the applied workflow stands out due to its flexibility and adaptability based on changes in the project scope. In the course of this case study, a sector roll-out of chemical EOR is elaborated, including a proposal for 27 new well candidates and 17 well conversions, resulting in an incremental oil production of 4.7MM bbl.\u0000 The key findings were: A workflow is introduced that delivers a fully stochastic economic evaluation while honoring the input and measured data.The delivered scenarios are conditioned to the geological information and the production history in a Bayesian Framework to ensure full consistency of the selected subsurface model advanced to forecasting.The applied process results in substantial time reduction for an EOR re-development project evaluation cycle.","PeriodicalId":10981,"journal":{"name":"Day 4 Thu, November 18, 2021","volume":"156 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77626773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maniesh Singh, Parmanand Dhermeshwar Thakur, Mariam N. M. Al Baloushi, Haitham Ali Al Saadi, Maisoon M. Al Mansoori, Ahmed S. Al Mesafri, S. Al Arfi, Vikram K. Pandey, Alaa Al Shalabi, F. Maire, Ernesto L. Barragan Chang, Maher M. Kenawy, Mouza Ali Al Nuaimi, Douglas Boyd, Nader Gerges, W. Fares, E. Bikchandaev, N. Clegg, A. Walmsley, A. Aki
An Ultra-Deep Directional Electromagnetic LWD Resistivity (UDDE) tool was deployed in a mature Lower Cretaceous carbonate reservoir to map injection water movement. These thick carbonate reservoirs experience injection water preferentially travelling laterally at the top of the reservoir. The water held above oil by negative capillary forces slumps quickly, leading to increasing water cut, eventually killing the natural lift horizontal producing well. Real time 3D and 1D inversions provided important accurate mapping of the non-uniform water fronts and reservoir boundaries, providing insights into reservoir architecture and water movement. The candidate well is located in an area of significant uncertainty regarding fluid distribution and structural elements like sub-seismic faults etc. Pre-well 1D inversion results indicated that the water slumping front away from wellbore can be mapped within a vertical radius of 60-100 ft TVD. However, 1D inversion is not accurate where steeply dipping or discontinuous formations exist due to the presence of faults and is expected to impact well placement, mapping water fronts / formation boundaries and long-term oil recovery. Therefore in the real time, full 3D and 1D inversions of the Ultra-Deep EM data were run to provide high quality reservoir imaging in this complex geometrical setting and deliver improved reservoir fluid distribution and structure mapping. The pre-well inversion modeling optimized the frequency and transmitter-receiver spacing of the UDDE tool. The bottom hole assembly (BHA) configuration also included conventional LWD tools such as Neutron-Density, propagation Resistivity and Gamma Ray. Multiple 3D inversion datasets were processed in real-time using different depths of inversion ranging from 50 ft up to 120 ft depth. The 3D inversion results during the real-time drilling operation detected the non-uniform waterfront boundaries and water slumping up to 80 ft TVD above the wellbore using a slimhole (4¾″) tool. An interpreted sub-seismic down-thrown fault was mapped which controlled the non-uniform slumping fluid distribution, causing the water front to approach closest to the wellbore in this location. This suggests that the fault zone is open and provides a degree of increased permeability around the plane of the fault. The real-time 3D inversion, 1D shallow and 1D deep inversion results showed comparable structural imaging despite being inverted independently of each other. These results permitted updates to the static / dynamic reservoir models and an optimization of the completion design, to delay the water influx and thereby sustain oil production for a longer period of time. Field wide implementation of the UDDE tool and its advanced technology with improved 1D and 3D inversion results will enhance the quality of realtime geosteering, mapping and updating of reservoir models which have challenging water slumping fronts and structural variations. This will enable improvment in
超深定向电磁LWD电阻率(UDDE)工具应用于成熟的下白垩统碳酸盐岩储层，以绘制注水运动图。在这些厚的碳酸盐岩储层中，注水优先在储层顶部横向流动。负毛细力作用下，油上方的水迅速下降，导致含水率增加，最终扼杀自然举升水平生产井。实时3D和1D反演提供了非均匀水面和油藏边界的重要精确映射，提供了对油藏结构和水运动的深入了解。该候选井位于流体分布和亚地震断层等构造元素具有重大不确定性的区域。井前一维反演结果表明，可以在60-100 ft TVD的垂直半径范围内绘制出远离井筒的水滑塌前缘。然而，由于断层的存在，在陡峭倾斜或不连续地层存在的情况下，一维反演并不准确，预计会影响井位、绘制水前缘/地层边界和长期采收率。因此，实时运行超深电磁数据的全3D和1D反演，在这种复杂的几何环境中提供高质量的储层成像，并提供改进的储层流体分布和结构映射。井前反演建模优化了UDDE工具的频率和收发间距。底部钻具组合(BHA)配置还包括传统的随钻测井工具，如中子密度、传播电阻率和伽马射线。利用50英尺至120英尺深度的不同反演深度，对多个三维反演数据集进行实时处理。使用小井眼(4¾″)工具，实时钻井过程中的三维反演结果检测到不均匀的滨水边界和井筒上方80英尺TVD处的水倾降。绘制了一条解释的次地震下倾断层，该断层控制了不均匀的滑塌流体分布，使该位置的水前缘最接近井筒。这表明断裂带是开放的，并且在断层平面周围提供了一定程度的渗透率增加。实时三维反演、一维浅反演和一维深反演结果虽然相互独立反演，但结构成像具有可比性。这些结果可以更新静态/动态油藏模型，并优化完井设计，以延迟水侵，从而在更长的时间内维持石油生产。UDDE工具及其先进技术在现场的广泛应用，改进了1D和3D反演结果，将提高具有挑战性的水滑塌前缘和结构变化的油藏模型的实时地质导向、测绘和更新的质量。这将有助于改善井位和井距，并最终实现智能完井的主动设计，以提高石油产量和采收率。
{"title":"Real-Time 3D Ultra Deep Directional Electromagnetic LWD Inversions: An Innovative Approach for Geosteering and Geomapping Water Slumping Movement Around Sub-Seismic Fault, Onshore Abu Dhabi","authors":"Maniesh Singh, Parmanand Dhermeshwar Thakur, Mariam N. M. Al Baloushi, Haitham Ali Al Saadi, Maisoon M. Al Mansoori, Ahmed S. Al Mesafri, S. Al Arfi, Vikram K. Pandey, Alaa Al Shalabi, F. Maire, Ernesto L. Barragan Chang, Maher M. Kenawy, Mouza Ali Al Nuaimi, Douglas Boyd, Nader Gerges, W. Fares, E. Bikchandaev, N. Clegg, A. Walmsley, A. Aki","doi":"10.2118/207478-ms","DOIUrl":"https://doi.org/10.2118/207478-ms","url":null,"abstract":"\u0000 An Ultra-Deep Directional Electromagnetic LWD Resistivity (UDDE) tool was deployed in a mature Lower Cretaceous carbonate reservoir to map injection water movement. These thick carbonate reservoirs experience injection water preferentially travelling laterally at the top of the reservoir. The water held above oil by negative capillary forces slumps quickly, leading to increasing water cut, eventually killing the natural lift horizontal producing well. Real time 3D and 1D inversions provided important accurate mapping of the non-uniform water fronts and reservoir boundaries, providing insights into reservoir architecture and water movement.\u0000 The candidate well is located in an area of significant uncertainty regarding fluid distribution and structural elements like sub-seismic faults etc. Pre-well 1D inversion results indicated that the water slumping front away from wellbore can be mapped within a vertical radius of 60-100 ft TVD. However, 1D inversion is not accurate where steeply dipping or discontinuous formations exist due to the presence of faults and is expected to impact well placement, mapping water fronts / formation boundaries and long-term oil recovery. Therefore in the real time, full 3D and 1D inversions of the Ultra-Deep EM data were run to provide high quality reservoir imaging in this complex geometrical setting and deliver improved reservoir fluid distribution and structure mapping. The pre-well inversion modeling optimized the frequency and transmitter-receiver spacing of the UDDE tool. The bottom hole assembly (BHA) configuration also included conventional LWD tools such as Neutron-Density, propagation Resistivity and Gamma Ray.\u0000 Multiple 3D inversion datasets were processed in real-time using different depths of inversion ranging from 50 ft up to 120 ft depth. The 3D inversion results during the real-time drilling operation detected the non-uniform waterfront boundaries and water slumping up to 80 ft TVD above the wellbore using a slimhole (4¾″) tool. An interpreted sub-seismic down-thrown fault was mapped which controlled the non-uniform slumping fluid distribution, causing the water front to approach closest to the wellbore in this location. This suggests that the fault zone is open and provides a degree of increased permeability around the plane of the fault. The real-time 3D inversion, 1D shallow and 1D deep inversion results showed comparable structural imaging despite being inverted independently of each other. These results permitted updates to the static / dynamic reservoir models and an optimization of the completion design, to delay the water influx and thereby sustain oil production for a longer period of time.\u0000 Field wide implementation of the UDDE tool and its advanced technology with improved 1D and 3D inversion results will enhance the quality of realtime geosteering, mapping and updating of reservoir models which have challenging water slumping fronts and structural variations. This will enable improvment in ","PeriodicalId":10981,"journal":{"name":"Day 4 Thu, November 18, 2021","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74295433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Massonnat, C. Danquigny, Emmanuelle Leonforte, L. Dal Soglio, M. Barbier, J. Lesueur
In carbonate reservoirs, because of the diversity of geological processes involved in the reservoir construction, the extrapolation of properties directly from well data to reservoir model gridblocks may lead to poorly predictive reservoir properties and then production forecasts. This paper proposes a modelling workflow in which new tools from disruptive technologies are associated in order to produce reservoir models consistently with reservoir geological construction. The workflow combines the simulation of the depositional facies and their transformation after diagenesis overprint. Original depositional facies are carried out from SED-RES™, a stratigraphic forward modelling software that generates and transports carbonate sediments according to ecological conditions and wind-induced currents. Then GODIAG™, a lattice gas, reproduces the evolution of the properties of the sediment after it has been deposited. The diagenesis history can be multi-stage and can involve different kinds of physical and chemical reactions. This new workflow has been evaluated in the framework of the ALBION R&D Project dedicated to the study of the Barremian-Aptian rudist-rich carbonate platform from south France that is known as an analogue of the Kharaib and Shuaiba reservoirs (UAE). Thanks to its multi-scale and multi-site aspect, ALBION offers the opportunity to test new modelling tools. The efficiency of the new workflow has been successfully applied on a sector model from an ALBION site on which a rich geological and petrophysical dataset is available from outcrops and numerous wells,
{"title":"A Multi-Process Reservoir Modelling Workflow as the Key for Unlocking Reservoir Prediction in Carbonates. Application to a Sector Model from the Albion R&D Project","authors":"G. Massonnat, C. Danquigny, Emmanuelle Leonforte, L. Dal Soglio, M. Barbier, J. Lesueur","doi":"10.2118/207556-ms","DOIUrl":"https://doi.org/10.2118/207556-ms","url":null,"abstract":"\u0000 In carbonate reservoirs, because of the diversity of geological processes involved in the reservoir construction, the extrapolation of properties directly from well data to reservoir model gridblocks may lead to poorly predictive reservoir properties and then production forecasts.\u0000 This paper proposes a modelling workflow in which new tools from disruptive technologies are associated in order to produce reservoir models consistently with reservoir geological construction. The workflow combines the simulation of the depositional facies and their transformation after diagenesis overprint. Original depositional facies are carried out from SED-RES™, a stratigraphic forward modelling software that generates and transports carbonate sediments according to ecological conditions and wind-induced currents. Then GODIAG™, a lattice gas, reproduces the evolution of the properties of the sediment after it has been deposited. The diagenesis history can be multi-stage and can involve different kinds of physical and chemical reactions.\u0000 This new workflow has been evaluated in the framework of the ALBION R&D Project dedicated to the study of the Barremian-Aptian rudist-rich carbonate platform from south France that is known as an analogue of the Kharaib and Shuaiba reservoirs (UAE). Thanks to its multi-scale and multi-site aspect, ALBION offers the opportunity to test new modelling tools. The efficiency of the new workflow has been successfully applied on a sector model from an ALBION site on which a rich geological and petrophysical dataset is available from outcrops and numerous wells,","PeriodicalId":10981,"journal":{"name":"Day 4 Thu, November 18, 2021","volume":"52 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76000282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper focuses on the use of modular construction techniques for installing geosynthetics in petroleum related applications. The petroleum industry uses geosynthetics for drill pad liners, above-ground and in-ground containment ponds, storage tanks, various impoundments including tailings storage, floating covers, road creation and/or support to remote sites, filtration, lining freshwater storage areas, dewatering, and stormwater management. Accelerating the construction of these facilities and the quality, i.e., no leaks, of the installation will have a positive impact on the financial and environmental aspects of the petroleum industry. Modular construction is a process in which a petroleum containment system is constructed primarily off-site, under controlled factory conditions, using the same design, materials, equipment, testing, and construction quality assurance and control (CQA/CQC) techniques as a field constructed facility – but usually in about one-half the time, for significantly less cost, and with few, if any, defects. This is due to the clean and constant conditions present in a factory setting. For example, installation of a factory-fabricated geomembrane can occur simultaneously while site work is being conducted. With factory fabrication, no destructive sampling and testing of the field welds that join rolls of the geomembrane are needed. As a result, a factory fabricated geomembrane can be installed in at least one-half of the time required for traditional field fabrication and with higher quality. This results in the containment system being utilized sooner, being more protective, and creating a faster return on investment.
{"title":"Modular Construction with Geosynthetics in Petroleum Industry","authors":"T. Stark, Calvin Stapleton","doi":"10.2118/207246-ms","DOIUrl":"https://doi.org/10.2118/207246-ms","url":null,"abstract":"\u0000 This paper focuses on the use of modular construction techniques for installing geosynthetics in petroleum related applications. The petroleum industry uses geosynthetics for drill pad liners, above-ground and in-ground containment ponds, storage tanks, various impoundments including tailings storage, floating covers, road creation and/or support to remote sites, filtration, lining freshwater storage areas, dewatering, and stormwater management. Accelerating the construction of these facilities and the quality, i.e., no leaks, of the installation will have a positive impact on the financial and environmental aspects of the petroleum industry. Modular construction is a process in which a petroleum containment system is constructed primarily off-site, under controlled factory conditions, using the same design, materials, equipment, testing, and construction quality assurance and control (CQA/CQC) techniques as a field constructed facility – but usually in about one-half the time, for significantly less cost, and with few, if any, defects. This is due to the clean and constant conditions present in a factory setting. For example, installation of a factory-fabricated geomembrane can occur simultaneously while site work is being conducted. With factory fabrication, no destructive sampling and testing of the field welds that join rolls of the geomembrane are needed. As a result, a factory fabricated geomembrane can be installed in at least one-half of the time required for traditional field fabrication and with higher quality. This results in the containment system being utilized sooner, being more protective, and creating a faster return on investment.","PeriodicalId":10981,"journal":{"name":"Day 4 Thu, November 18, 2021","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78876435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Tsusaka, Tatsuya Fuji, M. Shaver, D. P. Yudhia, M. Toma, S. A. Al Ali, T. Toki, Erwan Couzigou, H. Matsubuchi
In the studied oil field in Offshore Abu Dhabi, the intermediate hole section has suffered from borehole instability and lost circulation in the higher inclination holes. Borehole instability occurs in the Nahr Umr formation. Lost circulation occurs in the Salabikh formation. This study aims to develop geomechanical model and to analyze mud weight (MW) for successful drilling through the two problematic formations in the studied oil field. In the Salabikh formation, spatial distribution of lost circulation pressure in hundreds of wells in the whole field was analyzed. The fracture closure pressure was also evaluated based on the extended leak-off test and fracture interpretation by image logging. In the Nahr Umr formation, Micro-Frac tests in a 6" hole were implemented to evaluate the minimum in-situ stress. This was the first direct measurement of the in-situ stress in the shale. The magnitude of SHMAX was back-analyzed based on the hole geometry using interpretation of six-arm caliper and analytical solution in the two key locations. This study clarified that severe lost circulation in the crest area was likely to occur due to reactivation of the pre-existing fractures in the Salabikh formation. The lost circulation pressure was found to be approximately 1.4 SG. The study also revealed that the in-situ stress regime in the Nahr Umr formation varied from the crest to flank areas. The crest and flank areas are reverse and nearly normal faulting stress regimes, respectively. Its transition area is strike-slip faulting stress regime. The regional difference in in-situ stress regime depends on the extent of mechanical anisotropy of the shale and the magnitude of tectonic strains. By integrating the results, with respect to the borehole stability analysis in the Nahr Umr formation, instead of a conventional lower hemisphere representation of the required MW based on failure width at borehole wall, the study analyzed the geometry of the failure area around the borehole wall under the allowable range of MW constrained by the lost circulation pressure in the Salabikh formation. As a result, the borehole failure cannot be avoided in any hole inclination in the Nahr Umr formation under the allowable range of MW to prevent severe lost circulation in the Salabikh formation. Therefore, appropriate practice to transport cavings is one of the key elements for safe drilling in higher hole inclination across the intermediate hole section in the studied oil field.
{"title":"Geomechanical Modeling Based on the First Success of Micro-Frac Tests in the Nahr Umr Formation in Offshore Abu Dhabi","authors":"K. Tsusaka, Tatsuya Fuji, M. Shaver, D. P. Yudhia, M. Toma, S. A. Al Ali, T. Toki, Erwan Couzigou, H. Matsubuchi","doi":"10.2118/207653-ms","DOIUrl":"https://doi.org/10.2118/207653-ms","url":null,"abstract":"\u0000 In the studied oil field in Offshore Abu Dhabi, the intermediate hole section has suffered from borehole instability and lost circulation in the higher inclination holes. Borehole instability occurs in the Nahr Umr formation. Lost circulation occurs in the Salabikh formation. This study aims to develop geomechanical model and to analyze mud weight (MW) for successful drilling through the two problematic formations in the studied oil field. In the Salabikh formation, spatial distribution of lost circulation pressure in hundreds of wells in the whole field was analyzed. The fracture closure pressure was also evaluated based on the extended leak-off test and fracture interpretation by image logging. In the Nahr Umr formation, Micro-Frac tests in a 6\" hole were implemented to evaluate the minimum in-situ stress. This was the first direct measurement of the in-situ stress in the shale. The magnitude of SHMAX was back-analyzed based on the hole geometry using interpretation of six-arm caliper and analytical solution in the two key locations. This study clarified that severe lost circulation in the crest area was likely to occur due to reactivation of the pre-existing fractures in the Salabikh formation. The lost circulation pressure was found to be approximately 1.4 SG. The study also revealed that the in-situ stress regime in the Nahr Umr formation varied from the crest to flank areas. The crest and flank areas are reverse and nearly normal faulting stress regimes, respectively. Its transition area is strike-slip faulting stress regime. The regional difference in in-situ stress regime depends on the extent of mechanical anisotropy of the shale and the magnitude of tectonic strains. By integrating the results, with respect to the borehole stability analysis in the Nahr Umr formation, instead of a conventional lower hemisphere representation of the required MW based on failure width at borehole wall, the study analyzed the geometry of the failure area around the borehole wall under the allowable range of MW constrained by the lost circulation pressure in the Salabikh formation. As a result, the borehole failure cannot be avoided in any hole inclination in the Nahr Umr formation under the allowable range of MW to prevent severe lost circulation in the Salabikh formation. Therefore, appropriate practice to transport cavings is one of the key elements for safe drilling in higher hole inclination across the intermediate hole section in the studied oil field.","PeriodicalId":10981,"journal":{"name":"Day 4 Thu, November 18, 2021","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75680708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：