The ability to measure formation petro physical properties thru drillpipe has always been a challenge. It requires unconventional approaches to remove the effects of metal and borehole fluids on both the transmitted and received logging signals. This paper will present a proven technology executed in more than 1,000 wells all over the world and a first two successful trail case study from ADNOC Onshore wells in the Middle East. The main objective is to acquire triple combo data (resistivity, density, neutron, gamma ray, spectral gamma ray & caliper) using the LWT conveyance and acquisition technology where there is a high risk of downhole triple combo Logging While Drilling (LWD) and or wireline (WL) tools getting stuck and the risk of losing radioactive sources. The new patent pending technique was executed by using a slim downhole measurement tools inside specially designed drill collars invisible to the measurement sensors. LWT collars can be used for drilling and reaming as with normal drill collars. Propagation resistivity and neutron measurements are mostly like conventional techniques in tools physics. Density and nuclear caliper are measured by modelling the responses of three detectors short, medium and long distance away from the cesium source. The measured LWT log data has been validated through back to back comparisons with WL & LWD) logs showing almost one to one correlation considering the effects of mud invasion due to lapsed time between runs, different wellbore condition and different depth of investigations. Measured caliper, resistivity, density, neutron from LWT showed respectable match with WL or LWD tool. The differences in log responses are explained by differences in tool physics, logging speeds and environmental conditions. Similarly, the computed porosity from LWT tool comparison with WL and LWT porosity has almost the same statistics. The Quality LWT data was acquired in both wells at virtually zero LIH risk and minimum extra drilling rig time. Introducing the new LWT technique to measure accurate Open Hole formation evaluation data from inside the drill-string is a cost-effective solution in various challenging scenarios, Exploratory/ Appraisal/ Development risky & challenging wells with unknown reservoir pressures or unsystematic depletion scenarios, complex downhole in-situ stress regimes, challenging tectonically faulted or fractured areas & unstable shales and many more, posing challenge to drill stable holes and a threat to LWD/ WL radioactive tool stuck.Unplanned deviated 8-1/2′ hole section geo-steered by MWD-GR, where at last minute triple combo is desired.
{"title":"Open-Hole Logging While Tripping LWT Through Drill Pipes, as a New Technology for Risk Mitigation and Cost Optimization in Abu Dhabi Onshore Fields","authors":"Fathy ElWazeer, H. A. Chaker, Maarten Propper","doi":"10.2118/194781-MS","DOIUrl":"https://doi.org/10.2118/194781-MS","url":null,"abstract":"\u0000 The ability to measure formation petro physical properties thru drillpipe has always been a challenge. It requires unconventional approaches to remove the effects of metal and borehole fluids on both the transmitted and received logging signals. This paper will present a proven technology executed in more than 1,000 wells all over the world and a first two successful trail case study from ADNOC Onshore wells in the Middle East.\u0000 The main objective is to acquire triple combo data (resistivity, density, neutron, gamma ray, spectral gamma ray & caliper) using the LWT conveyance and acquisition technology where there is a high risk of downhole triple combo Logging While Drilling (LWD) and or wireline (WL) tools getting stuck and the risk of losing radioactive sources.\u0000 The new patent pending technique was executed by using a slim downhole measurement tools inside specially designed drill collars invisible to the measurement sensors. LWT collars can be used for drilling and reaming as with normal drill collars. Propagation resistivity and neutron measurements are mostly like conventional techniques in tools physics. Density and nuclear caliper are measured by modelling the responses of three detectors short, medium and long distance away from the cesium source.\u0000 The measured LWT log data has been validated through back to back comparisons with WL & LWD) logs showing almost one to one correlation considering the effects of mud invasion due to lapsed time between runs, different wellbore condition and different depth of investigations.\u0000 Measured caliper, resistivity, density, neutron from LWT showed respectable match with WL or LWD tool. The differences in log responses are explained by differences in tool physics, logging speeds and environmental conditions. Similarly, the computed porosity from LWT tool comparison with WL and LWT porosity has almost the same statistics. The Quality LWT data was acquired in both wells at virtually zero LIH risk and minimum extra drilling rig time.\u0000 Introducing the new LWT technique to measure accurate Open Hole formation evaluation data from inside the drill-string is a cost-effective solution in various challenging scenarios, Exploratory/ Appraisal/ Development risky & challenging wells with unknown reservoir pressures or unsystematic depletion scenarios, complex downhole in-situ stress regimes, challenging tectonically faulted or fractured areas & unstable shales and many more, posing challenge to drill stable holes and a threat to LWD/ WL radioactive tool stuck.Unplanned deviated 8-1/2′ hole section geo-steered by MWD-GR, where at last minute triple combo is desired.","PeriodicalId":11031,"journal":{"name":"Day 4 Thu, March 21, 2019","volume":"7 4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78429521","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}
The proposed paper presents a detailed study on evolving CO2 due to calcite mineral dissolution, and its ensuing activity during the matrix acidizing of sanstone reservoirs. Coreflood experiments were conducted in acidizing, and interpreted via simulation studies using a three-phase, two scale continuum model. Sensitivity studies were then performed on the calibrated simulation model. Acid injection was performed on 6 in.-length, 1.5 in.-diameter Bandera Brown sandstone cores of variable calcite content, using 15 wt% HCl single-phase coreflood experiments at high back pressures were conducted to calibrate and initially test the three-phase, two-scale continuum model. Experimentally measured rock-heterogeneity via computed tomography (CT) scans, relative-permeability and capillary pressures, oil-water interfacial tension and contact-angle parameters were inputs for three-phase, two-scale model-based history matching and sensitivity studies. The three-phase, two-scale continuum model was able to match all performed coreflood experiments with a good level of accuracy. The acid-calcite chemical reaction parameters were fixed in all cases to ensure consistency in analysis. Oil production was observed, with an average of 40% recovery of the residual oil in place at CO2 miscible pressures. CO2 miscibility in oil enhances swelling with time, which was seen as the main mechanism for oil production. A direct symmetry was observed between the oil recovery and average CO2 moles in oil. The recovery curve flattened once surrounding oil reached its full-saturation level with CO2. Reduction in oil-water interfacial-tension increased the recovery factor only by a slight margin, owing to dependency on evolved CO2 volume. Immiscible CO2 conditions yielded no residual oil recovery. The successful application of the three-phase, two-scale continuum model approach sets a new bar in the area of sandstone acidizing. The acid breakthrough criterion has been revised toward application in a three-phase environment. The potential of CO2, a by-product of acidizing, towards its contribution in swelling oil in the presence of a three-phase environment, and towards possible oil recovery in the event of flowing back a well.
{"title":"Three-Phase Sandstone Acidizing: Quantification and Analysis of Evolved CO2 in the Presence of Oil and Water","authors":"Sajjaat Muhemmed, H. Kumar, H. Nasr-El-Din","doi":"10.2118/194776-MS","DOIUrl":"https://doi.org/10.2118/194776-MS","url":null,"abstract":"\u0000 The proposed paper presents a detailed study on evolving CO2 due to calcite mineral dissolution, and its ensuing activity during the matrix acidizing of sanstone reservoirs. Coreflood experiments were conducted in acidizing, and interpreted via simulation studies using a three-phase, two scale continuum model. Sensitivity studies were then performed on the calibrated simulation model. Acid injection was performed on 6 in.-length, 1.5 in.-diameter Bandera Brown sandstone cores of variable calcite content, using 15 wt% HCl single-phase coreflood experiments at high back pressures were conducted to calibrate and initially test the three-phase, two-scale continuum model. Experimentally measured rock-heterogeneity via computed tomography (CT) scans, relative-permeability and capillary pressures, oil-water interfacial tension and contact-angle parameters were inputs for three-phase, two-scale model-based history matching and sensitivity studies. The three-phase, two-scale continuum model was able to match all performed coreflood experiments with a good level of accuracy. The acid-calcite chemical reaction parameters were fixed in all cases to ensure consistency in analysis. Oil production was observed, with an average of 40% recovery of the residual oil in place at CO2 miscible pressures. CO2 miscibility in oil enhances swelling with time, which was seen as the main mechanism for oil production. A direct symmetry was observed between the oil recovery and average CO2 moles in oil. The recovery curve flattened once surrounding oil reached its full-saturation level with CO2. Reduction in oil-water interfacial-tension increased the recovery factor only by a slight margin, owing to dependency on evolved CO2 volume. Immiscible CO2 conditions yielded no residual oil recovery. The successful application of the three-phase, two-scale continuum model approach sets a new bar in the area of sandstone acidizing. The acid breakthrough criterion has been revised toward application in a three-phase environment. The potential of CO2, a by-product of acidizing, towards its contribution in swelling oil in the presence of a three-phase environment, and towards possible oil recovery in the event of flowing back a well.","PeriodicalId":11031,"journal":{"name":"Day 4 Thu, March 21, 2019","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91253392","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}
Electrically resistive composite casing materials are being introduced to the oil & gas industry. Resistive casing enables electromagnetic logging for exploration and reservoir monitoring, but it requires development of new logging methods. Here we present a technique for the detection of integrity of magnetic cement behind resistive casing. We demonstrate that an optimized induction logging tool can detect small changes in the magnetic permeability of cement through a non-conductive casing in a vertical (or horizontal) well. We can determine both integrity and solidification state of the cement filling annulus behind casing. Changes in magnetic permeability influence mostly the real part of the vertical component of magnetic field. The signal amplitude is more sensitive to a change of magnetic properties of the cement, rather than the signal phase. Our simulations show that optimum separation between the transmitter and receiver coils ranges from 0.25 to 0.6 meters, and the most suitable magnetic field frequencies vary from 0.1 to 10 kHz. A high-frequency induction probe operating at 200 MHz can measure the degree of solidification of cement. The proposed method can detect borehole cracks filled with cement, incomplete lift of cement, casing eccentricity and other borehole in homogeneities.
{"title":"Beyond Steel Casing: Detecting Zonal Isolation in the Borehole Environment","authors":"T. Eltsov, T. Patzek","doi":"10.2118/195036-MS","DOIUrl":"https://doi.org/10.2118/195036-MS","url":null,"abstract":"\u0000 Electrically resistive composite casing materials are being introduced to the oil & gas industry. Resistive casing enables electromagnetic logging for exploration and reservoir monitoring, but it requires development of new logging methods. Here we present a technique for the detection of integrity of magnetic cement behind resistive casing. We demonstrate that an optimized induction logging tool can detect small changes in the magnetic permeability of cement through a non-conductive casing in a vertical (or horizontal) well. We can determine both integrity and solidification state of the cement filling annulus behind casing. Changes in magnetic permeability influence mostly the real part of the vertical component of magnetic field. The signal amplitude is more sensitive to a change of magnetic properties of the cement, rather than the signal phase. Our simulations show that optimum separation between the transmitter and receiver coils ranges from 0.25 to 0.6 meters, and the most suitable magnetic field frequencies vary from 0.1 to 10 kHz. A high-frequency induction probe operating at 200 MHz can measure the degree of solidification of cement. The proposed method can detect borehole cracks filled with cement, incomplete lift of cement, casing eccentricity and other borehole in homogeneities.","PeriodicalId":11031,"journal":{"name":"Day 4 Thu, March 21, 2019","volume":"157 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78224923","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}
South Ordos sandstone reservoir is mainly featured by tiny pore, which mainstream throat radius is around 50nm, high filtration resistance, resulting in low oil productivity and more obvious non-linear seepage characteristics. As of low formation pressure, well production is poor and declines dramatically, therefore primary recovery is hard to sustain effective development for the reservoir. The core problem of tight oil development focuses on the evaluation of tight matrix flowing capability and reservoir producing condition. In the paper, in Ordos typical tight oil basin, by means of microscopic flowing simulation, numerical simulation as well as lab experiments results, single-phase and oil-water two-phrase flowing mechanisms have been analyzed, revealing tight oil single phase percolating resistance and movable oil saturation, providing key evaluation parameters for effective reservoir division. For oil-water two-phase flowing, Jamin effect is so serious that water flooding is hard to displace the oil in micro-pores, accordingly relative permeability and displacement efficiency are calculated. Tight matrix-fracture coupling model recovery mechanism have been analyzed, effective producing radius and mechanism of matrix are defined in the condition of fracturing horizontal wells developing, according to which productivity percentage of Ordos tight oil between fracture and matrix have been determined. On basis of geology evaluation and reservoir engineering analysis, correlation of geological properties-well dynamic characteristics are set up, then influencing factors have been studied to identify tight oil producing conditions on depletion development at different oil price. As different classified fracture developed in the reservoir, water flooding producing condition has been studied, laying the foundation for study of effective development method and technical strategy. Our research indicates that Ordos tight matrix is of low productivity, with movable water saturation increasing, well productivity sharp decline. During production period, production ratio from fracture is only amounted to 6~14% of accumulation oil. Fully excavating the potential of matrix reserves is predominant to achieve effective development of tight oil. Owing to high start-up pressure gradient, as high as 0.1~0.2MPa/m, for water flooding development, well spacing should be reduced to 50m□ to set up pressure response without fracture developing. While in Ordos basin natural fracture is developed, water channeling is so heavy that accumulative oil is lower than depletion method. CO2 start-up pressure gradient is far smaller than that of water flooding with composite EOR mechanisms, expected to be an effective injection medium for tight oil. It is a critical period how so many shut-in wells could be revitalized under low oil price condition. Relying on research results, Ordos tight oil new development method target has been determined, promoting application research a
{"title":"Study of Tight Oil Flowing Mechanism and Reservoir Producing Conditions for South Edge of Ordos Basin","authors":"Xu Ting, Pu Jun, Qin Xuejie, Yi Wei, Song Wenfang","doi":"10.2118/195001-MS","DOIUrl":"https://doi.org/10.2118/195001-MS","url":null,"abstract":"\u0000 South Ordos sandstone reservoir is mainly featured by tiny pore, which mainstream throat radius is around 50nm, high filtration resistance, resulting in low oil productivity and more obvious non-linear seepage characteristics. As of low formation pressure, well production is poor and declines dramatically, therefore primary recovery is hard to sustain effective development for the reservoir. The core problem of tight oil development focuses on the evaluation of tight matrix flowing capability and reservoir producing condition.\u0000 In the paper, in Ordos typical tight oil basin, by means of microscopic flowing simulation, numerical simulation as well as lab experiments results, single-phase and oil-water two-phrase flowing mechanisms have been analyzed, revealing tight oil single phase percolating resistance and movable oil saturation, providing key evaluation parameters for effective reservoir division. For oil-water two-phase flowing, Jamin effect is so serious that water flooding is hard to displace the oil in micro-pores, accordingly relative permeability and displacement efficiency are calculated. Tight matrix-fracture coupling model recovery mechanism have been analyzed, effective producing radius and mechanism of matrix are defined in the condition of fracturing horizontal wells developing, according to which productivity percentage of Ordos tight oil between fracture and matrix have been determined. On basis of geology evaluation and reservoir engineering analysis, correlation of geological properties-well dynamic characteristics are set up, then influencing factors have been studied to identify tight oil producing conditions on depletion development at different oil price. As different classified fracture developed in the reservoir, water flooding producing condition has been studied, laying the foundation for study of effective development method and technical strategy.\u0000 Our research indicates that Ordos tight matrix is of low productivity, with movable water saturation increasing, well productivity sharp decline. During production period, production ratio from fracture is only amounted to 6~14% of accumulation oil. Fully excavating the potential of matrix reserves is predominant to achieve effective development of tight oil. Owing to high start-up pressure gradient, as high as 0.1~0.2MPa/m, for water flooding development, well spacing should be reduced to 50m□ to set up pressure response without fracture developing. While in Ordos basin natural fracture is developed, water channeling is so heavy that accumulative oil is lower than depletion method. CO2 start-up pressure gradient is far smaller than that of water flooding with composite EOR mechanisms, expected to be an effective injection medium for tight oil.\u0000 It is a critical period how so many shut-in wells could be revitalized under low oil price condition. Relying on research results, Ordos tight oil new development method target has been determined, promoting application research a","PeriodicalId":11031,"journal":{"name":"Day 4 Thu, March 21, 2019","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78477723","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}
Dragon Oil operates the Cheleken field in the Caspian Sea offshore Turkmenistan. The production system consists of multiple wellhead and manifold platforms, a complex network of infield carbon steel and flexible flowlines to handle production from HP and LP systems and a 30" × 40 km TL to transport the produced fluids to the CPSF (Central Processing and Storage Facility) located onshore. In addition to the complexities of the flowlines network, the development has a number of unique features that pose challenges to the daily production operation activities such as: -Relatively low reservoir temperatures;-Waxy oil with high WAT (Wax Appearance Temperature) and Pour Point;-Complicated bathymetry of the 30" TL (Trunkline);-Complex reservoirs leading to uncertainty in rates;-Increasing water production;-Increasing sand ingress;-Necessity to commingle water from different sources in the flowlines;-Corrosion, erosion and emulsion occurrence; While management of any of the Flow Assurance issues is well understood on stand-alone basis; there is no definite guidelines to manage them simultaneously through understanding their impact on each other. Obtaining flawless understanding of the nature and extent of each of the impediments issues was a key element for Dragon Oil's team to innovate this approach to minimizing the overall negative impact on production operations. The approach has been developed based on balancing the hydrophobic, hydrophilic and molecular properties of the produced fluids in correlation with the physical criteria of each of the issues to minimize the impact on the others. This paper presents the key elements of a novel approach developed to control the impact of some issues and maintain the deliverability and integrity of the 30" TL. The approach consisted of the following activities:Conducted thorough and rigorous fluids’ analyses;Generated comprehensive operating pressure-temperature envelop during different operational and ambient conditions in the 30" TL;Constructed the occurrence envelops of Flow Assurance issues focusing on wax deposition and severe slugging;Ensured adequacy of slug catching capability at the CPSF and proper procedures to operate;Controlled gas rates to generate severe slugging in the 30" TL;Monitored the performance of the 30" TL (and eventually the system) through close observations to the changes in the key controlling parameters e.g. pressure drop, outcomes of pigging operations and efficiency of separation.
{"title":"From Pore to Process: Novel Flow Assurance Approach to Suppress Severe Production Chemistry Issues by Flow Dynamic Characterization","authors":"Amir T. Alwazzan, M. Dashtebayaz, Mohamed Fiaz","doi":"10.2118/194768-MS","DOIUrl":"https://doi.org/10.2118/194768-MS","url":null,"abstract":"\u0000 Dragon Oil operates the Cheleken field in the Caspian Sea offshore Turkmenistan. The production system consists of multiple wellhead and manifold platforms, a complex network of infield carbon steel and flexible flowlines to handle production from HP and LP systems and a 30\" × 40 km TL to transport the produced fluids to the CPSF (Central Processing and Storage Facility) located onshore. In addition to the complexities of the flowlines network, the development has a number of unique features that pose challenges to the daily production operation activities such as: -Relatively low reservoir temperatures;-Waxy oil with high WAT (Wax Appearance Temperature) and Pour Point;-Complicated bathymetry of the 30\" TL (Trunkline);-Complex reservoirs leading to uncertainty in rates;-Increasing water production;-Increasing sand ingress;-Necessity to commingle water from different sources in the flowlines;-Corrosion, erosion and emulsion occurrence;\u0000 While management of any of the Flow Assurance issues is well understood on stand-alone basis; there is no definite guidelines to manage them simultaneously through understanding their impact on each other. Obtaining flawless understanding of the nature and extent of each of the impediments issues was a key element for Dragon Oil's team to innovate this approach to minimizing the overall negative impact on production operations. The approach has been developed based on balancing the hydrophobic, hydrophilic and molecular properties of the produced fluids in correlation with the physical criteria of each of the issues to minimize the impact on the others.\u0000 This paper presents the key elements of a novel approach developed to control the impact of some issues and maintain the deliverability and integrity of the 30\" TL. The approach consisted of the following activities:Conducted thorough and rigorous fluids’ analyses;Generated comprehensive operating pressure-temperature envelop during different operational and ambient conditions in the 30\" TL;Constructed the occurrence envelops of Flow Assurance issues focusing on wax deposition and severe slugging;Ensured adequacy of slug catching capability at the CPSF and proper procedures to operate;Controlled gas rates to generate severe slugging in the 30\" TL;Monitored the performance of the 30\" TL (and eventually the system) through close observations to the changes in the key controlling parameters e.g. pressure drop, outcomes of pigging operations and efficiency of separation.","PeriodicalId":11031,"journal":{"name":"Day 4 Thu, March 21, 2019","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77264667","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}
Shale has been a major destination for unconventional hydrocarbon resources for its wide stratigraphic coverage as well as high volumetric hydrocarbon potential. Contemporary success in North American shale plays has intrigued operators worldwide in shale exploration. Organic richness has been a key factor to determine the potential of shale as it is proportional to the amount of hydrocarbon likely to be generated and stored in available spaces within the shale. The other important factor in this context is shale brittleness as it indicates how fracable the potential shale is. Attempts are made here by strategically using standard wireline logs in order to evaluate potential of Eocene Vadaparru Shale in Krishna Godavari Basin, India qualitatively and quantitatively. The technique used in this study involves identification of organic lean ‘clean shale’ interval and establishing a ‘clean shale’ relation of resistivity as a function of compressional sonic transit time in the study wells, as both the logs respond comparably to shale and its organic content. Using this relation a proxy ‘clean shale’ resistivity log is generated in shale and compared with measured wireline resistivity. A positive separation between calculated and measured resistivity is then assessed as proportionate shale organic richness, owing to the presence of relatively less dense (corresponding to longer sonic transit time) and more resistive organic content. Shale brittleness is predicted from Young's modulus and Poisson's ratio using compressional, shear and Stoneley wave velocities obtained from sonic measurements, assuming transversely isotropic nature of Vadaparru Shale. The Eocene marine transgressive Vadaparru Shale is a dominant stratigraphy in KG basin as evident from seismics and drilling. Petrophysical analyses in study wells indicated appreciable brittleness within Vadaparru Shale. The organic richness i.e. amount of positive separation between calculated and measured resistivity combined with brittleness quantitatively indicate fair to excellent unconventional potential of Vadaparru Shale. Considerable thickness, Type-II, III kerogen content and geochemical measurements support the study and highlight it as a promising ‘shale reservoir’ destination. In the context of rapidly growing energy demand of India Vadaparru Shale can be considered as serious unconventional player. Overall this study presents quick strategy for shale potential quantification, thus allowing operators to focus spatially in the quest of unconventional hydrocarbon resources.
{"title":"Petrophysical Evaluation of Organic Richness and Brittleness of Shale for Unconventional Hydrocarbon Prospecting: A Case Study on Vadaparru Shale, Krishna Godavari Basin, India","authors":"Arijit Sahu, M. K. Das","doi":"10.2118/194976-MS","DOIUrl":"https://doi.org/10.2118/194976-MS","url":null,"abstract":"\u0000 \u0000 \u0000 Shale has been a major destination for unconventional hydrocarbon resources for its wide stratigraphic coverage as well as high volumetric hydrocarbon potential. Contemporary success in North American shale plays has intrigued operators worldwide in shale exploration. Organic richness has been a key factor to determine the potential of shale as it is proportional to the amount of hydrocarbon likely to be generated and stored in available spaces within the shale. The other important factor in this context is shale brittleness as it indicates how fracable the potential shale is. Attempts are made here by strategically using standard wireline logs in order to evaluate potential of Eocene Vadaparru Shale in Krishna Godavari Basin, India qualitatively and quantitatively.\u0000 \u0000 \u0000 \u0000 The technique used in this study involves identification of organic lean ‘clean shale’ interval and establishing a ‘clean shale’ relation of resistivity as a function of compressional sonic transit time in the study wells, as both the logs respond comparably to shale and its organic content. Using this relation a proxy ‘clean shale’ resistivity log is generated in shale and compared with measured wireline resistivity. A positive separation between calculated and measured resistivity is then assessed as proportionate shale organic richness, owing to the presence of relatively less dense (corresponding to longer sonic transit time) and more resistive organic content. Shale brittleness is predicted from Young's modulus and Poisson's ratio using compressional, shear and Stoneley wave velocities obtained from sonic measurements, assuming transversely isotropic nature of Vadaparru Shale.\u0000 \u0000 \u0000 \u0000 The Eocene marine transgressive Vadaparru Shale is a dominant stratigraphy in KG basin as evident from seismics and drilling. Petrophysical analyses in study wells indicated appreciable brittleness within Vadaparru Shale. The organic richness i.e. amount of positive separation between calculated and measured resistivity combined with brittleness quantitatively indicate fair to excellent unconventional potential of Vadaparru Shale. Considerable thickness, Type-II, III kerogen content and geochemical measurements support the study and highlight it as a promising ‘shale reservoir’ destination. In the context of rapidly growing energy demand of India Vadaparru Shale can be considered as serious unconventional player.\u0000 \u0000 \u0000 \u0000 Overall this study presents quick strategy for shale potential quantification, thus allowing operators to focus spatially in the quest of unconventional hydrocarbon resources.\u0000","PeriodicalId":11031,"journal":{"name":"Day 4 Thu, March 21, 2019","volume":"128 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85560609","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. Grutters, S. Shetty, Winthrop Brown, R. Dunn, Brendan Coadey
There is a growing demand for digital solutions to improve efficiency of oil & gas processing. The ultimate goal is digital platforms that connect multiple information sources, both software and hardware, to make better operational decisions and dramatically improve efficiency. Development of these holistic platforms is still relatively new, although various smaller applications of data digitization and equipment automation do exist. In this paper three field cases will be given to demonstrate the powerful benefits of data digitization and automation. Field Case 1 describes a data management tool that connects field data with SAP and LIMS. The customizable surveillance screens refresh with new laboratory data as soon as they are uploaded in LIMS, and show how water composition trends in relation to corrosion coupons help to optimize costs for corrosion inhibitor. Field Case 2 describes a completely autonomous injection skid to mitigate H2S in a well that requires periodic intervention for paraffin treatment. A scavenger is injected downhole at a dosage rate that is determined by real-time H2S analysers coupled with production flow data, and maintains a zero concentration of H2S at the well head. This novel solution improves personnel safety by enabling work-over crews to work under less hazardous conditions. Field Case 3 describes an automated system for a refinery cooling water system, where a single controller orchestrates five chemical injection pumps based on real-time input from multiple analysers and sensors. From these field cases it can be concluded that digitization and automation tools provide easy, cost- effective and powerful solutions to improve efficiency in oilfield operations. It enables field operators and managers to focus on value adding tasks. When the vast downstream experience of using sophisticated controllers, sensors and analysers is applied to upstream environments efficiency in oil & gas processing facilities can be further improved with lower human intervention.
{"title":"Automation in Upstream Production Chemicals: Learning from Downstream","authors":"M. Grutters, S. Shetty, Winthrop Brown, R. Dunn, Brendan Coadey","doi":"10.2118/195112-MS","DOIUrl":"https://doi.org/10.2118/195112-MS","url":null,"abstract":"\u0000 There is a growing demand for digital solutions to improve efficiency of oil & gas processing. The ultimate goal is digital platforms that connect multiple information sources, both software and hardware, to make better operational decisions and dramatically improve efficiency. Development of these holistic platforms is still relatively new, although various smaller applications of data digitization and equipment automation do exist. In this paper three field cases will be given to demonstrate the powerful benefits of data digitization and automation. Field Case 1 describes a data management tool that connects field data with SAP and LIMS. The customizable surveillance screens refresh with new laboratory data as soon as they are uploaded in LIMS, and show how water composition trends in relation to corrosion coupons help to optimize costs for corrosion inhibitor. Field Case 2 describes a completely autonomous injection skid to mitigate H2S in a well that requires periodic intervention for paraffin treatment. A scavenger is injected downhole at a dosage rate that is determined by real-time H2S analysers coupled with production flow data, and maintains a zero concentration of H2S at the well head. This novel solution improves personnel safety by enabling work-over crews to work under less hazardous conditions. Field Case 3 describes an automated system for a refinery cooling water system, where a single controller orchestrates five chemical injection pumps based on real-time input from multiple analysers and sensors. From these field cases it can be concluded that digitization and automation tools provide easy, cost- effective and powerful solutions to improve efficiency in oilfield operations. It enables field operators and managers to focus on value adding tasks. When the vast downstream experience of using sophisticated controllers, sensors and analysers is applied to upstream environments efficiency in oil & gas processing facilities can be further improved with lower human intervention.","PeriodicalId":11031,"journal":{"name":"Day 4 Thu, March 21, 2019","volume":"56 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88620469","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 study offers a thorough assessment of two contract awarding strategies; Lump Sum Turn Key (LSTK) Versus Lump Sum Procure and Build (LSPB) conducted specifically for C1(≤100 Million USD) budget projects. The study objective is to access and compare the Pros and Cons of each type of awarding strategies over four specific aspects; (1) project budget size, (2) awarding period length, (3) procurement cycle, and (4) level of engineering detail design scope of work. The effect of the project driver and stakeholders’ requirement on each of the 4 aspects is considered and analyzed. Also, the effect of a fifth aspect (brown field Vs green field) is evaluated and introduced in our study as "control". This assessment is conducted as a case study for an ongoing C1 budget project. The evaluation compares realistic time frames utilizing PERT and GANTT charts. The time frames are extracted from processes mandated by "Company" Engineering procedures" SAEP". The two awarding strategies are analyzed using "5 WHYs" technique and fish-bone analysis method for this specific case study. The project activities critical path was driven and analyzed. Level 3 schedules are built using Primavera Software. Data for all 4 aspects were obtained from the company Bench Mark projects and recommended procedures. It was observed that each of aspect number (1), (2), and (3) on its own cannot be a decisive measure to choose a specific contracting strategy for this specific low budget category, C1 projects. You need the stakeholders requirement that is translated into project initiating driver as a core input to steer the decision for selecting the contract awarding strategy. Hence, the assessment of selecting the awarding strategy for C1 projects would show different results if the project is "Cost Driven" Versus if it is to "Schedule Driven′′. For instance, if the project is initiated to maintain business then, the stakeholders would be expediting the execution and completion of the project. Thus, Project Management Team (PMT) will be on great pressure to visit all time saving avenues starting with the contracting strategy. On the other hand, if the project is cost driven then, the awarding strategy that results in lower expenditures will be selected. However, the study concluded that the level of complexity of the engineering detail design scope for a C1 project should be a decisive factor on its own for the choice of the contract awarding strategy. The reason for this conclusion is to avoid wasting valuable resources that could be exhausted in rework. This assessment was conducted using top notch project management softwares merged with lean management methodologies. The author is a strong advocate of introducing lean thinking in project management of Oil and Gas construction project. In his current job with "The Company", he is implementing Lean thinking and process improvement techniques in all project management responsibilities and has published a paper with MOES 2017
{"title":"Assessment of Two Contract Awarding Strategies; Lump Sum Turn Key LSTK and Lump Sum Procure and Build LSPB for Low Budget Oil and Gas Construction Projects C1; Less than 100 Million USD","authors":"M. Ibrahim","doi":"10.2118/195033-MS","DOIUrl":"https://doi.org/10.2118/195033-MS","url":null,"abstract":"\u0000 This study offers a thorough assessment of two contract awarding strategies; Lump Sum Turn Key (LSTK) Versus Lump Sum Procure and Build (LSPB) conducted specifically for C1(≤100 Million USD) budget projects. The study objective is to access and compare the Pros and Cons of each type of awarding strategies over four specific aspects; (1) project budget size, (2) awarding period length, (3) procurement cycle, and (4) level of engineering detail design scope of work. The effect of the project driver and stakeholders’ requirement on each of the 4 aspects is considered and analyzed. Also, the effect of a fifth aspect (brown field Vs green field) is evaluated and introduced in our study as \"control\". This assessment is conducted as a case study for an ongoing C1 budget project. The evaluation compares realistic time frames utilizing PERT and GANTT charts. The time frames are extracted from processes mandated by \"Company\" Engineering procedures\" SAEP\". The two awarding strategies are analyzed using \"5 WHYs\" technique and fish-bone analysis method for this specific case study. The project activities critical path was driven and analyzed. Level 3 schedules are built using Primavera Software.\u0000 Data for all 4 aspects were obtained from the company Bench Mark projects and recommended procedures. It was observed that each of aspect number (1), (2), and (3) on its own cannot be a decisive measure to choose a specific contracting strategy for this specific low budget category, C1 projects. You need the stakeholders requirement that is translated into project initiating driver as a core input to steer the decision for selecting the contract awarding strategy. Hence, the assessment of selecting the awarding strategy for C1 projects would show different results if the project is \"Cost Driven\" Versus if it is to \"Schedule Driven′′. For instance, if the project is initiated to maintain business then, the stakeholders would be expediting the execution and completion of the project. Thus, Project Management Team (PMT) will be on great pressure to visit all time saving avenues starting with the contracting strategy. On the other hand, if the project is cost driven then, the awarding strategy that results in lower expenditures will be selected. However, the study concluded that the level of complexity of the engineering detail design scope for a C1 project should be a decisive factor on its own for the choice of the contract awarding strategy. The reason for this conclusion is to avoid wasting valuable resources that could be exhausted in rework. This assessment was conducted using top notch project management softwares merged with lean management methodologies. The author is a strong advocate of introducing lean thinking in project management of Oil and Gas construction project. In his current job with \"The Company\", he is implementing Lean thinking and process improvement techniques in all project management responsibilities and has published a paper with MOES 2017 ","PeriodicalId":11031,"journal":{"name":"Day 4 Thu, March 21, 2019","volume":"72 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88794053","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}
S. Greenhalgh, A. Al-Lehyani, C. Schmelzbach, D. Sollberger
The bearing and elevation (azimuth and inclination) of a seismic event can be estimated directly from measurements at a single triaxial station. There are instances in which the angular resolution secured by triaxial polarization analysis is better than that obtained by beamforming with an extended scalar array. In these situations, one depends totally on understanding the inter-relationships between the triaxial records that make up a seismic wavetrain. There are many approaches to seismic direction finding (SDF). Monte-Carlo techniques of triaxial seismic direction finding seek to maximise signal power by examining the seismic wavefield in many rotated co-ordinate frames. There are variants on this approach, which entail null seeking in an inverse space. Instead of searching all possible directions for the one which best fits the polarization model of a single arrival, it is possible to carry out an eigen-decomposition of the (complex or real) covariance matrix formed from the three-component data. The eigenvector corresponding to the principal eigenvalue yields the polarization direction automatically, with significant savings in computational effort. Numerical experiments undertaken for different levels of random noise superimposed on a pure mode signal show that there are no significant advantages in using the Monte-Carlo techniques over eigendecompsoition. Confidence measures of event detection may be obtained by examining eigenvalue ratios when using the eigendecompsoition method. A time-domain formulation (covariance or coherency matrix) is preferable to a frequency-domain formulation (cross-spectral matrix) when there are multiple transient events present. The analysis window should be as long as possible (at least half the dominant period of the signal) without causing separate events to interfere. In practise, the direction-of-arrival estimates deteriorate with increasing levels of random noise, and are generally unacceptable for a SNR of less than 1. Special care is needed to avoid direction errors associated with systematic noise, such as sensor gain misalignment between channels, coupling variations between receiver components, velocity inhomogeneity and anisotropy, the free-surface effect, and multiple event interference.
{"title":"Single Station Triaxial Seismic Event Detection, Direction Finding and Polarization Analysis","authors":"S. Greenhalgh, A. Al-Lehyani, C. Schmelzbach, D. Sollberger","doi":"10.2118/194941-MS","DOIUrl":"https://doi.org/10.2118/194941-MS","url":null,"abstract":"\u0000 The bearing and elevation (azimuth and inclination) of a seismic event can be estimated directly from measurements at a single triaxial station. There are instances in which the angular resolution secured by triaxial polarization analysis is better than that obtained by beamforming with an extended scalar array. In these situations, one depends totally on understanding the inter-relationships between the triaxial records that make up a seismic wavetrain. There are many approaches to seismic direction finding (SDF). Monte-Carlo techniques of triaxial seismic direction finding seek to maximise signal power by examining the seismic wavefield in many rotated co-ordinate frames. There are variants on this approach, which entail null seeking in an inverse space. Instead of searching all possible directions for the one which best fits the polarization model of a single arrival, it is possible to carry out an eigen-decomposition of the (complex or real) covariance matrix formed from the three-component data. The eigenvector corresponding to the principal eigenvalue yields the polarization direction automatically, with significant savings in computational effort.\u0000 Numerical experiments undertaken for different levels of random noise superimposed on a pure mode signal show that there are no significant advantages in using the Monte-Carlo techniques over eigendecompsoition. Confidence measures of event detection may be obtained by examining eigenvalue ratios when using the eigendecompsoition method. A time-domain formulation (covariance or coherency matrix) is preferable to a frequency-domain formulation (cross-spectral matrix) when there are multiple transient events present. The analysis window should be as long as possible (at least half the dominant period of the signal) without causing separate events to interfere.\u0000 In practise, the direction-of-arrival estimates deteriorate with increasing levels of random noise, and are generally unacceptable for a SNR of less than 1. Special care is needed to avoid direction errors associated with systematic noise, such as sensor gain misalignment between channels, coupling variations between receiver components, velocity inhomogeneity and anisotropy, the free-surface effect, and multiple event interference.","PeriodicalId":11031,"journal":{"name":"Day 4 Thu, March 21, 2019","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82837899","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}
A. Amer, A. Sajer, T. Al-Adwani, Hanan Salem, R. Abu-Taleb, Ali Abu-Guneej, A. Yateem, Vishnu Chilumuri, P. Goyal, S. Devkar
Producing unconventional reservoirs characterized by low porosities and permeabilities during early stages of exploration and field appraisal can be challenging, especially in high temperature and high pressure (HPHT) downhole conditions. In such reservoirs, the natural fracture network can play a significant role in flowing hydrocarbons, increasing the importance of encountering such network by the boreholes. Consequently, the challenge would be to plan wells through these corridors, which is not always easy. To add to the challenge, well design restrictions dictate, the drilling of only vertical and in minor cases deviated wells. This can reduce the possibility of drilling through sub-vertical fracture sets significantly, and once seismic resolution is considered, it may seem that all odds are agents encountering a fracture network. This article addresses a case where a vertical well is drilled, in the above-mentioned reservoir setting, and missed the natural fracture system. The correct mitigation can make a difference between plugging and abandoning the well or putting it on production. The technique utilized is based on a borehole acoustic reflection survey (BARS) acquired over a vertical well to give a detailed insight on the fracture network 120 ft away from the borehole. Integrating this technique with core and high-resolution borehole image logs rendered an excellent match, increasing the confidence level in the acoustically predicted fracture corridors. Based on these findings new perforation intervals and hydraulic stimulation are proposed to optimize well performance. Such application can reverse the well decommissioning process, opening new opportunities for the rejuvenation of older wells.
{"title":"The Application of Downhole Seismic Imaging in Identifying Natural Fracture Systems; An Integrated Approach Utilizing Core and Borehole Image Data","authors":"A. Amer, A. Sajer, T. Al-Adwani, Hanan Salem, R. Abu-Taleb, Ali Abu-Guneej, A. Yateem, Vishnu Chilumuri, P. Goyal, S. Devkar","doi":"10.2118/194903-MS","DOIUrl":"https://doi.org/10.2118/194903-MS","url":null,"abstract":"\u0000 Producing unconventional reservoirs characterized by low porosities and permeabilities during early stages of exploration and field appraisal can be challenging, especially in high temperature and high pressure (HPHT) downhole conditions. In such reservoirs, the natural fracture network can play a significant role in flowing hydrocarbons, increasing the importance of encountering such network by the boreholes.\u0000 Consequently, the challenge would be to plan wells through these corridors, which is not always easy. To add to the challenge, well design restrictions dictate, the drilling of only vertical and in minor cases deviated wells. This can reduce the possibility of drilling through sub-vertical fracture sets significantly, and once seismic resolution is considered, it may seem that all odds are agents encountering a fracture network.\u0000 This article addresses a case where a vertical well is drilled, in the above-mentioned reservoir setting, and missed the natural fracture system. The correct mitigation can make a difference between plugging and abandoning the well or putting it on production.\u0000 The technique utilized is based on a borehole acoustic reflection survey (BARS) acquired over a vertical well to give a detailed insight on the fracture network 120 ft away from the borehole. Integrating this technique with core and high-resolution borehole image logs rendered an excellent match, increasing the confidence level in the acoustically predicted fracture corridors.\u0000 Based on these findings new perforation intervals and hydraulic stimulation are proposed to optimize well performance. Such application can reverse the well decommissioning process, opening new opportunities for the rejuvenation of older wells.","PeriodicalId":11031,"journal":{"name":"Day 4 Thu, March 21, 2019","volume":"52 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90824647","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}
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