F. Agbor, S. Mhlambi, N. A. Teumahji, W. Sonibare, J. Donker, T. Chatterjee
Despite the undergoing exploration and research for hydrocarbons during the recent decades, the hydrocarbon potentials of existing source rock(s) in the Pletmos basin still remain enigmatic. The basin has undergone rifting and transforms processes during its evolution in a manner that its present-day architecture and geodynamic evolution can only be better understood through the application of a multidisciplinary and multi-scale geo-modelling procedure. In the study, thermal modelling and reconstruction of burial history of the source rocks in the southern depocenter of the Pletmos Basin has been investigated through an integration of data and methods. Through geohistory Modelling, an integration of the acquired multidisciplinary dataset allowed us to reconstruct the burial history, basement subsidence, vertical fluid flow, and the changes in rock properties (i.e. porosity, permeability, pressure and fluid flow rate) both in time and depth, as well as established a reliable tectonostratigraphic framework of the Mesozoic sedimentary infill. Then based on the reconstructed burial history, thermal history was reconstructed by modifying the paleoheat flux to minimize variances, and comparing between measured borehole and predicted vitrinite reflectance and Tmax (thermal indicator) values. These enable us to achieve an improved understanding of the subsurface controlling processes that might have led to the sedimentary infill and resulted to the heat-flow distribution and present-day thermal maturity of the source rocks in the Basin. The approach gives us the opportunity to considered the geodynamic evolution events from Mesozoic (Upper Jurassic) rifting to Cenozoic (including major uplifts, erosion and subsidence, and the Shona Buvet hot spots). Here we present some selected results, from the burial and thermal history modelling reconstructions of the sedimentary geothermal evolution and thermal maturity levels of the source rocks at selected well locations within the area. Likewise, this study has provided supplementary information that aids towards understanding the Petroleum System(s) of the Basin.
{"title":"Geohistory Reconstruction and Maturity Modelling in the Southern Pletmos Basin, Offshore of South Africa","authors":"F. Agbor, S. Mhlambi, N. A. Teumahji, W. Sonibare, J. Donker, T. Chatterjee","doi":"10.2118/192617-MS","DOIUrl":"https://doi.org/10.2118/192617-MS","url":null,"abstract":"\u0000 Despite the undergoing exploration and research for hydrocarbons during the recent decades, the hydrocarbon potentials of existing source rock(s) in the Pletmos basin still remain enigmatic. The basin has undergone rifting and transforms processes during its evolution in a manner that its present-day architecture and geodynamic evolution can only be better understood through the application of a multidisciplinary and multi-scale geo-modelling procedure.\u0000 In the study, thermal modelling and reconstruction of burial history of the source rocks in the southern depocenter of the Pletmos Basin has been investigated through an integration of data and methods.\u0000 Through geohistory Modelling, an integration of the acquired multidisciplinary dataset allowed us to reconstruct the burial history, basement subsidence, vertical fluid flow, and the changes in rock properties (i.e. porosity, permeability, pressure and fluid flow rate) both in time and depth, as well as established a reliable tectonostratigraphic framework of the Mesozoic sedimentary infill. Then based on the reconstructed burial history, thermal history was reconstructed by modifying the paleoheat flux to minimize variances, and comparing between measured borehole and predicted vitrinite reflectance and Tmax (thermal indicator) values. These enable us to achieve an improved understanding of the subsurface controlling processes that might have led to the sedimentary infill and resulted to the heat-flow distribution and present-day thermal maturity of the source rocks in the Basin. The approach gives us the opportunity to considered the geodynamic evolution events from Mesozoic (Upper Jurassic) rifting to Cenozoic (including major uplifts, erosion and subsidence, and the Shona Buvet hot spots). Here we present some selected results, from the burial and thermal history modelling reconstructions of the sedimentary geothermal evolution and thermal maturity levels of the source rocks at selected well locations within the area. Likewise, this study has provided supplementary information that aids towards understanding the Petroleum System(s) of the Basin.","PeriodicalId":11014,"journal":{"name":"Day 1 Mon, November 12, 2018","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88294621","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}
Eglier Yanez, M. Uijttenhout, M. Zidan, R. Salimov, S. Al-jaberi, A. Al-Shamsi, Amnah Al-Sereidi, M. Amer, Yousef Ahmed Alhammadi, A. Abdul-Halim, Giovani Caletti, Mustapha Adli, Yousif Hasan Al-Hammadi, Fahad Mustafa Al-Hosani
Including "smartness" in your field does not necessarily add additional expenditures. ADNOC Offshore piloted a new well completion design combining Interval Control Valves (ICVs) in the shallow reservoir and Inflow Control Devices (ICDs) in the deeper reservoir, both deployed in a water injector well for the first time in the company. The objectives were to improve reservoir management, reduce well construction complexity and achieve one of the main business targets of cost optimization. This paper covers the subsurface study, detailed well construction design, completion deployment, well intervention and overall well performance in commingled injection mode. A multi-disciplinary study was conducted based on updated reservoir data available after the first two years of production in a heterogeneous multi reservoir field. This study showed the possibility of replacing the upper horizontal drain by a deviated perforated section. The authors identified the need of completion compartmentalization to overcome challenges such as high reservoir heterogeneity and uneven pressure depletion enforced by non selective acid stimulation. As part of the evaluation, a simulation was performed to evaluate the expected injection performance across the four zones with different combinations of ICVs and ICDs in order to cater for different injection scenarios. As a result of the integrated analysis, a new well completion design was deployed to optimize a Dual Horizontal Water Injector into a Single Smart Completion with 3 Inflow Control Valves (ICVs) covering the upper perforated zones and 14 Inflow Control Devices (ICDs) with sliding sleeves across lower lateral reservoir. Cost savings and reduction of rig time was achieved with this new completion design demonstrating very pro-active participation from all involved teams, ADNOC Offshore and Service Companies. The requirements to complete high and low permeability zones in one single well can be successfully accomplished. Firstly, mitigation of early water breakthrough is achieved by incorporating surface water injection control in high permeable zones and secondly, the injection target for the low permeable reservoir is also delivered. Building on the successful results and captured lesson learnt, this new well completion design provided the capabilities to optimize the water injection plan while reducing costs. Therefore, the project has passed the trial phase and the team proposed its implementation.
{"title":"Improving Field Development Through Successful Installation of Intelligent Completion on Water Injector Well","authors":"Eglier Yanez, M. Uijttenhout, M. Zidan, R. Salimov, S. Al-jaberi, A. Al-Shamsi, Amnah Al-Sereidi, M. Amer, Yousef Ahmed Alhammadi, A. Abdul-Halim, Giovani Caletti, Mustapha Adli, Yousif Hasan Al-Hammadi, Fahad Mustafa Al-Hosani","doi":"10.2118/192850-MS","DOIUrl":"https://doi.org/10.2118/192850-MS","url":null,"abstract":"\u0000 Including \"smartness\" in your field does not necessarily add additional expenditures. ADNOC Offshore piloted a new well completion design combining Interval Control Valves (ICVs) in the shallow reservoir and Inflow Control Devices (ICDs) in the deeper reservoir, both deployed in a water injector well for the first time in the company. The objectives were to improve reservoir management, reduce well construction complexity and achieve one of the main business targets of cost optimization. This paper covers the subsurface study, detailed well construction design, completion deployment, well intervention and overall well performance in commingled injection mode.\u0000 A multi-disciplinary study was conducted based on updated reservoir data available after the first two years of production in a heterogeneous multi reservoir field. This study showed the possibility of replacing the upper horizontal drain by a deviated perforated section. The authors identified the need of completion compartmentalization to overcome challenges such as high reservoir heterogeneity and uneven pressure depletion enforced by non selective acid stimulation. As part of the evaluation, a simulation was performed to evaluate the expected injection performance across the four zones with different combinations of ICVs and ICDs in order to cater for different injection scenarios.\u0000 As a result of the integrated analysis, a new well completion design was deployed to optimize a Dual Horizontal Water Injector into a Single Smart Completion with 3 Inflow Control Valves (ICVs) covering the upper perforated zones and 14 Inflow Control Devices (ICDs) with sliding sleeves across lower lateral reservoir. Cost savings and reduction of rig time was achieved with this new completion design demonstrating very pro-active participation from all involved teams, ADNOC Offshore and Service Companies.\u0000 The requirements to complete high and low permeability zones in one single well can be successfully accomplished. Firstly, mitigation of early water breakthrough is achieved by incorporating surface water injection control in high permeable zones and secondly, the injection target for the low permeable reservoir is also delivered.\u0000 Building on the successful results and captured lesson learnt, this new well completion design provided the capabilities to optimize the water injection plan while reducing costs. Therefore, the project has passed the trial phase and the team proposed its implementation.","PeriodicalId":11014,"journal":{"name":"Day 1 Mon, November 12, 2018","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86532540","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}
B. Franco, M. Celentano, D. Popa, A. Taher, M. Al-Shehhi
Late Cretaceous plate collision and subsequent ophiolite emplacement at the eastern margin of the Arabian Plate led to compressional events, responsible for the formation of the structural traps of the giant fields onshore Abu Dhabi. In addition, the onset of this structuration during the Turonian caused the configuration of some hence-to-forth overlooked features (pinch-outs and siliciclastic sand deposits). The objective of the present work is to analyze the origin and distribution of these geometries and their potential to constitute stratigraphic traps. To understand the genesis and the distribution of these geometries which formed during the Late Cretaceous, we used a combination of large scale regional stratigraphic well correlations and seismic lines interpretation, together with age dating, core description, and well data information. The methodology consisted in using this data for detailed mapping of relevant time stratigraphic intervals, placing the mapped architecture in the context of the global eustatic sea levels and major geodynamic events of the Arabian Plate. The ensuing plate collision during the Turonian in eastern plate margin was felt hundreds of kilometers into the plate over Abu Dhabi area. Buckling and uplifting created paleo-relief which caused exposure and erosion of Wasia Group sediments in northern and eastern areas of Abu Dhabi Emirate. This led to the configuration of some overlooked stratigraphic features: eroded rims and lateral facies change against structural dip (Mishrif Formation); onlap pinch-outs onto flanks of major structures (Ruwaydhah Formations) and the deposition of siliciclastic sand deposits of the Tuwayil Formation. The features follow low relief areas along contemporaneous synclines in onshore Abu Dhabi and salt withdrawal synclines in offshore Abu Dhabi. With further advance of the obducting ophiolites, a foredeep developed leading to drowning of the previously exposed structures. Shales and interbedded limestones of the Laffan Formation were unconformably deposited over the eroded Wasia Group during the Coniacian transgression associated with the generation of this foredeep. They are now forming an extensive regional seal for these deposits forming potentially stratigraphic traps. We postulate that the rejuvenation of the Shilaif intrashelf basin during the Late Turonian and the deposition of the (Ruwaydhah Formation) was aborted at its early stages by periods of uplift, erosion and their successive erosional unconformities, features that are confirmed on the crest of several eastern area structures. This provided the context for the generation of pinch-out geometries that constitute potential stratigraphic traps downdip of major structures in Abu Dhabi. Very little has been published about the outline and architecture of these stratigraphic traps in Abu Dhabi and the detailed circumstances that led to their genesis, topics that are comprehensively analyzed in the pre
{"title":"Stratigraphic Traps Generation in Abu Dhabi as a Consequence of Ensuing Late Cretaceous Plate Collision and Obduction at the Eastern Arabian Plate Margin","authors":"B. Franco, M. Celentano, D. Popa, A. Taher, M. Al-Shehhi","doi":"10.2118/192928-MS","DOIUrl":"https://doi.org/10.2118/192928-MS","url":null,"abstract":"\u0000 \u0000 \u0000 Late Cretaceous plate collision and subsequent ophiolite emplacement at the eastern margin of the Arabian Plate led to compressional events, responsible for the formation of the structural traps of the giant fields onshore Abu Dhabi. In addition, the onset of this structuration during the Turonian caused the configuration of some hence-to-forth overlooked features (pinch-outs and siliciclastic sand deposits). The objective of the present work is to analyze the origin and distribution of these geometries and their potential to constitute stratigraphic traps.\u0000 \u0000 \u0000 \u0000 To understand the genesis and the distribution of these geometries which formed during the Late Cretaceous, we used a combination of large scale regional stratigraphic well correlations and seismic lines interpretation, together with age dating, core description, and well data information. The methodology consisted in using this data for detailed mapping of relevant time stratigraphic intervals, placing the mapped architecture in the context of the global eustatic sea levels and major geodynamic events of the Arabian Plate.\u0000 \u0000 \u0000 \u0000 The ensuing plate collision during the Turonian in eastern plate margin was felt hundreds of kilometers into the plate over Abu Dhabi area. Buckling and uplifting created paleo-relief which caused exposure and erosion of Wasia Group sediments in northern and eastern areas of Abu Dhabi Emirate. This led to the configuration of some overlooked stratigraphic features: eroded rims and lateral facies change against structural dip (Mishrif Formation); onlap pinch-outs onto flanks of major structures (Ruwaydhah Formations) and the deposition of siliciclastic sand deposits of the Tuwayil Formation. The features follow low relief areas along contemporaneous synclines in onshore Abu Dhabi and salt withdrawal synclines in offshore Abu Dhabi.\u0000 With further advance of the obducting ophiolites, a foredeep developed leading to drowning of the previously exposed structures. Shales and interbedded limestones of the Laffan Formation were unconformably deposited over the eroded Wasia Group during the Coniacian transgression associated with the generation of this foredeep. They are now forming an extensive regional seal for these deposits forming potentially stratigraphic traps.\u0000 We postulate that the rejuvenation of the Shilaif intrashelf basin during the Late Turonian and the deposition of the (Ruwaydhah Formation) was aborted at its early stages by periods of uplift, erosion and their successive erosional unconformities, features that are confirmed on the crest of several eastern area structures. This provided the context for the generation of pinch-out geometries that constitute potential stratigraphic traps downdip of major structures in Abu Dhabi.\u0000 \u0000 \u0000 \u0000 Very little has been published about the outline and architecture of these stratigraphic traps in Abu Dhabi and the detailed circumstances that led to their genesis, topics that are comprehensively analyzed in the pre","PeriodicalId":11014,"journal":{"name":"Day 1 Mon, November 12, 2018","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78454060","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}
Fahd I. Alghunaimi, Duaa Alsaeed, A. Harith, T. Saleh
This paper presents a novel/cost-effective hydrophobic material based 9-octadecenoic acid grafted graphene (POG) for oil/water separation. Graphene derived from graphite was modified with 9-octadecenoic acid to obtain 9-octadecenoic acid grafted graphene (OG). Then, emulsion polymerization of styrene was performed on OG to produce polystyrene branches on 9-octadecenoic acid grafted graphene (POG). Three different composites were prepared by varying the amount of 9-octadecenoic acid grafted graphene used as follows: POG25, POG50, and POG75. The three materials were characterized by using N2-physisorption and Fourier transform Infra-red (FTIR). The BET surface area of POG75 was 288 m2/g while POG50 was 225 m2/g and POG25 was 79 m2/g. These materials were evaluated for their oil/water separation efficiency using model mixture. The results showed that the higher the ratio of the 9-octadecenoic acid grafted graphene, the higher the oil removal efficiency of the material and the faster the rate of the adsorption. The materials showed not only high efficiency but also fast uptake of the certain quantity of the oil just within 1 minute. This can be explained by the high hydrophobicity nature of the materials which repel the water as confirmed by the contact angle of approximately 150°. POG75 showed promising results to be a good candidate adsorbent materials for oil removal from produced water where it displays the highest adsorption capability to organic compounds and the highest BET surface area. POG75 was regenerated and its performance was tested again. This material showed a slightly reduced adsorption rate in the first cycle compared to the fresh material. However, the adsorption rate was constant for the next several cycles. POG75 has the potential to be utilized to remove oil contaminants from produced water.
{"title":"Synthesis of Adsorbent Materials by Emulsion Polymerization for Efficient Oil/Water Separation and Hydrocarbons Recovery from Produced Water","authors":"Fahd I. Alghunaimi, Duaa Alsaeed, A. Harith, T. Saleh","doi":"10.2118/193188-MS","DOIUrl":"https://doi.org/10.2118/193188-MS","url":null,"abstract":"\u0000 This paper presents a novel/cost-effective hydrophobic material based 9-octadecenoic acid grafted graphene (POG) for oil/water separation. Graphene derived from graphite was modified with 9-octadecenoic acid to obtain 9-octadecenoic acid grafted graphene (OG). Then, emulsion polymerization of styrene was performed on OG to produce polystyrene branches on 9-octadecenoic acid grafted graphene (POG). Three different composites were prepared by varying the amount of 9-octadecenoic acid grafted graphene used as follows: POG25, POG50, and POG75. The three materials were characterized by using N2-physisorption and Fourier transform Infra-red (FTIR). The BET surface area of POG75 was 288 m2/g while POG50 was 225 m2/g and POG25 was 79 m2/g. These materials were evaluated for their oil/water separation efficiency using model mixture. The results showed that the higher the ratio of the 9-octadecenoic acid grafted graphene, the higher the oil removal efficiency of the material and the faster the rate of the adsorption. The materials showed not only high efficiency but also fast uptake of the certain quantity of the oil just within 1 minute. This can be explained by the high hydrophobicity nature of the materials which repel the water as confirmed by the contact angle of approximately 150°. POG75 showed promising results to be a good candidate adsorbent materials for oil removal from produced water where it displays the highest adsorption capability to organic compounds and the highest BET surface area. POG75 was regenerated and its performance was tested again. This material showed a slightly reduced adsorption rate in the first cycle compared to the fresh material. However, the adsorption rate was constant for the next several cycles. POG75 has the potential to be utilized to remove oil contaminants from produced water.","PeriodicalId":11014,"journal":{"name":"Day 1 Mon, November 12, 2018","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85936512","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. Lamberti, N. Colombi, M. Calderoni, F. Bombaci, L. Castelnuovo, G. Crema
2018 will be the brightest year for upstream investment since 2014. Costs reduction and the oil price stabilization gives operators confidence in launching new challenging projects. However, launching new projects is still particularly challenging for deep-water assets. Even if project costs are 20% lower than mid-2014, deep-water projects are not yet competitive with tight oil, considering also the higher associated uncertainty. The direction to improve is clear: further cost cuts, through leaner development principles and improved well designs. Moreover, operators have to take advantage from lesson learned of projects already in production. Eni has consolidated on its West Africa deep-water assets a workflow that can support challenging projects FID through: Reduction of time to market parallelizing project phasesManagement of project uncertainty through flexibilityWork in integrated teams taking advantage from digital transformation More in details, the first target is to reduce time to market anticipating free cash flow generation. This is achieved through an appraisal while developing phase: drilling appraisal as first wells of development campaign, derisking the following well locations. Time-to-market reduction is achieved by parallelizing development phases, starting development plan definition during exploration phases and anticipating procurement of long lead items. This is possible if subsurface uncertainty has been properly defined through robust 3D models and if projects can guarantee the flexibility to capture new opportunities: fine tune well locations during drilling campaign, keep spare slots availability and sidetrack opportunities, substitute water and gas injectors with water alternate gas wells (WAG). In addition, Digital Transformation offers more and more the possibility to continuously update 3D models thanks to the availability of real time data, run thousands of simulations on super computers and monitor in real time field performance, taking advantage from simple daily operations. This work is aimed to describe the steps that were the key successful factors of Eni operated deep water projects in West Africa. The presented workflow can now be considered a standard approach for the most challenging Eni's projects and supported the company to reach record time-to-market for the execution of challenging deep-water projects in the range of 2,5 to 4 years from authorization to first oil.
{"title":"Key Successful Factors in Deep Water Development - Eni Experience in West Africa","authors":"A. Lamberti, N. Colombi, M. Calderoni, F. Bombaci, L. Castelnuovo, G. Crema","doi":"10.2118/192681-MS","DOIUrl":"https://doi.org/10.2118/192681-MS","url":null,"abstract":"\u0000 2018 will be the brightest year for upstream investment since 2014. Costs reduction and the oil price stabilization gives operators confidence in launching new challenging projects.\u0000 However, launching new projects is still particularly challenging for deep-water assets. Even if project costs are 20% lower than mid-2014, deep-water projects are not yet competitive with tight oil, considering also the higher associated uncertainty.\u0000 The direction to improve is clear: further cost cuts, through leaner development principles and improved well designs. Moreover, operators have to take advantage from lesson learned of projects already in production.\u0000 Eni has consolidated on its West Africa deep-water assets a workflow that can support challenging projects FID through: Reduction of time to market parallelizing project phasesManagement of project uncertainty through flexibilityWork in integrated teams taking advantage from digital transformation\u0000 More in details, the first target is to reduce time to market anticipating free cash flow generation. This is achieved through an appraisal while developing phase: drilling appraisal as first wells of development campaign, derisking the following well locations. Time-to-market reduction is achieved by parallelizing development phases, starting development plan definition during exploration phases and anticipating procurement of long lead items.\u0000 This is possible if subsurface uncertainty has been properly defined through robust 3D models and if projects can guarantee the flexibility to capture new opportunities: fine tune well locations during drilling campaign, keep spare slots availability and sidetrack opportunities, substitute water and gas injectors with water alternate gas wells (WAG).\u0000 In addition, Digital Transformation offers more and more the possibility to continuously update 3D models thanks to the availability of real time data, run thousands of simulations on super computers and monitor in real time field performance, taking advantage from simple daily operations.\u0000 This work is aimed to describe the steps that were the key successful factors of Eni operated deep water projects in West Africa. The presented workflow can now be considered a standard approach for the most challenging Eni's projects and supported the company to reach record time-to-market for the execution of challenging deep-water projects in the range of 2,5 to 4 years from authorization to first oil.","PeriodicalId":11014,"journal":{"name":"Day 1 Mon, November 12, 2018","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86475329","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}
F. Brindle, M. Rafique, Rajesh Thatha, Stephen McCormick, Samuel Escott, Haroon Bajwa, M. Cocagne
Drill Pipe conveyance (TLC/PCL) of wireline logging tools or Logging While Drilling (LWD) is usually required for high deviation / high differential sticking risk logging scenarios. These are costly in terms of rig time and service company costs. This paper details how a full suite of high-quality open hole log data was obtained on wireline in a high angle 16,500ft wellbore utilizing a new conveyance system and a polymer-locked high strength cable. The new conveyance system, utilizing wheeled carriages and a holefinder with nose angled upwards, takes a holistic approach to tool conveyance, reducing drag while ensuring both correct tool orientation and optimum contact and standoff for each logging service. Management of tool centers of gravity relative to the wheel axes ensures correct orientation. The reduction in friction due to wheeled carriages vs weight and cable load is modelled before the operation in order to ensure successful runs, both into and out of the wellbore. Polymer-locked high strength cable significantly increases maximum safe pull capability and enhanced data transmission technology allows faster logging speeds, greater rig time efficiency and reduced sticking risk. The wheeled carriage system enabled conventional logging in a high angle well, minimized stick-slip and reduced differential sticking risk. The unique holefinder prevented tool hold up during descent. The Vertical Seismic Profile (VSP) run (the only run not able to utilize the system due to tool size and design) was held up on a ledge above the lowest reservoir of interest. The high strength cable allowed safe retrieval of tools (over-pull > 6000lbs) in one particularly sticky zone. In a world first, an array sonic tool was centralized through management of weighted and eccentralized tool sections using bespoke wheels. This eliminated the drag inherent to traditional methods of sonic centralization (centralization using powered calipers and/or spring centralizers), resulting in excellent data quality. Nuclear Magnetic Resonance logs were obtained by orienting the tool sensor with wheels which utilized tool weight to provide sensor application force. This removed the need for additional centralizers, resulting in data devoid of stick-slip artefacts (an issue in previous wells). The formation fluid sampling run was conveyed on drill pipe, taking 6 days of rig time. There are further significant efficiency gains to be had on future operations by using the new conveyance system on sampling tools (operators have already moved in this direction in the Gulf of Mexico).
{"title":"Use of New Wireline Conveyance Technologies on an Offshore Abu Dhabi Well Saves Significant Rig Time and Results in Improved Sonic and Nuclear Magnetic Resonance Data Quality","authors":"F. Brindle, M. Rafique, Rajesh Thatha, Stephen McCormick, Samuel Escott, Haroon Bajwa, M. Cocagne","doi":"10.2118/192876-MS","DOIUrl":"https://doi.org/10.2118/192876-MS","url":null,"abstract":"\u0000 Drill Pipe conveyance (TLC/PCL) of wireline logging tools or Logging While Drilling (LWD) is usually required for high deviation / high differential sticking risk logging scenarios. These are costly in terms of rig time and service company costs. This paper details how a full suite of high-quality open hole log data was obtained on wireline in a high angle 16,500ft wellbore utilizing a new conveyance system and a polymer-locked high strength cable.\u0000 The new conveyance system, utilizing wheeled carriages and a holefinder with nose angled upwards, takes a holistic approach to tool conveyance, reducing drag while ensuring both correct tool orientation and optimum contact and standoff for each logging service. Management of tool centers of gravity relative to the wheel axes ensures correct orientation. The reduction in friction due to wheeled carriages vs weight and cable load is modelled before the operation in order to ensure successful runs, both into and out of the wellbore. Polymer-locked high strength cable significantly increases maximum safe pull capability and enhanced data transmission technology allows faster logging speeds, greater rig time efficiency and reduced sticking risk.\u0000 The wheeled carriage system enabled conventional logging in a high angle well, minimized stick-slip and reduced differential sticking risk. The unique holefinder prevented tool hold up during descent. The Vertical Seismic Profile (VSP) run (the only run not able to utilize the system due to tool size and design) was held up on a ledge above the lowest reservoir of interest. The high strength cable allowed safe retrieval of tools (over-pull > 6000lbs) in one particularly sticky zone.\u0000 In a world first, an array sonic tool was centralized through management of weighted and eccentralized tool sections using bespoke wheels. This eliminated the drag inherent to traditional methods of sonic centralization (centralization using powered calipers and/or spring centralizers), resulting in excellent data quality. Nuclear Magnetic Resonance logs were obtained by orienting the tool sensor with wheels which utilized tool weight to provide sensor application force. This removed the need for additional centralizers, resulting in data devoid of stick-slip artefacts (an issue in previous wells).\u0000 The formation fluid sampling run was conveyed on drill pipe, taking 6 days of rig time. There are further significant efficiency gains to be had on future operations by using the new conveyance system on sampling tools (operators have already moved in this direction in the Gulf of Mexico).","PeriodicalId":11014,"journal":{"name":"Day 1 Mon, November 12, 2018","volume":"464 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84164442","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}
Thuraya Al Ghafri, Youngtak Seo, Jinhui Liu, Dong-Oh Kim, Ren Aijing, K. Belaid, Zhao Mingqiu, Jia Wenrui
The Arabian Gulf is prolific of low relief geological structures, however, their definition and imaging present in general a genuine challenge. It is also commonly understood that low relief structures won't benefit from Pre-Stack Depth Migration (PSDM) whereas, Pre-Stack Time Migration (PSTM) is the ultimate required process. Thus, PSTM is frequently applied for the imaging of these low relief structures. Nonetheless, our recent 3D PSDM processing work has demonstrated that this perception is not all the time correct and has proved that PSDM can indeed add significant value to low relief structures. An Anisotropic PSDM (APSDM) workflow was carefully designed and meticulously applied on a very low relief structure located onshore Abu Dhabi –UAE. The main objectives of this 3D Anisotropic PSDM processing were established as follows: Achieve an accurate & clearer depth structure image with higher resolution.Mitigate & address the observed depth uncertainties at the existing wells.Enhance the faults architecture & imaging.Analyze anisotropic velocity & build a reliable velocity model for depth imaging.Interpret azimuth volumes in depth & time domains. The designed processing workflow consisted of the following main five stages: Gathers pre-conditioning and residual noise attenuation adopting the principle of amplitude preservation.Velocity building & updating using available well data, interpreted horizons and applying VTI full azimuth and multi azimuth velocity tomography processes.Depth imaging using Kirchhoff PSDM in OVT (Offset Vector Tile) domain.Post migration processing for residual inter-bed multiples & noise attenuation in addition to azimuthal anisotropy analysis and final depth-tie examination.Post stack processing for acquisition foot print removal and signal to noise ratio (S/N) enhancement. It should be noted that the selection of the optimum processing parameters at all the processing steps was done after the implementation of an intensive testing & rigorous QC/QA procedures. The main results and findings revealed by the 3D Anisotropic PSDM processing and the subsequent 3D seismic data interpretation are summarized as follows: PSDM shows less depth uncertainty compared to PSTM at existing wells. However, based on the results of recent drilling activities which have been conducted after PSDM, depth uncertainty at new well locations still exists.Reliable velocity model was built for depth imaging. This was established after 12 tomography iterations carried out for the isotropic velocity model and four iterations of anisotropy updates and VTI azimuthal velocity tomography.Some low relief structures are better defined in PSDM than PSTM.Seismic continuity of some target levels has been improved.Seismic resolution is degraded due to the limited frequency content.Fault imaging has been improved at some locations.
{"title":"Value of PSDM Processing on Low Relief Structure in East Onshore Abu Dhabi","authors":"Thuraya Al Ghafri, Youngtak Seo, Jinhui Liu, Dong-Oh Kim, Ren Aijing, K. Belaid, Zhao Mingqiu, Jia Wenrui","doi":"10.2118/193161-MS","DOIUrl":"https://doi.org/10.2118/193161-MS","url":null,"abstract":"\u0000 The Arabian Gulf is prolific of low relief geological structures, however, their definition and imaging present in general a genuine challenge. It is also commonly understood that low relief structures won't benefit from Pre-Stack Depth Migration (PSDM) whereas, Pre-Stack Time Migration (PSTM) is the ultimate required process. Thus, PSTM is frequently applied for the imaging of these low relief structures.\u0000 Nonetheless, our recent 3D PSDM processing work has demonstrated that this perception is not all the time correct and has proved that PSDM can indeed add significant value to low relief structures.\u0000 An Anisotropic PSDM (APSDM) workflow was carefully designed and meticulously applied on a very low relief structure located onshore Abu Dhabi –UAE.\u0000 The main objectives of this 3D Anisotropic PSDM processing were established as follows: Achieve an accurate & clearer depth structure image with higher resolution.Mitigate & address the observed depth uncertainties at the existing wells.Enhance the faults architecture & imaging.Analyze anisotropic velocity & build a reliable velocity model for depth imaging.Interpret azimuth volumes in depth & time domains.\u0000 The designed processing workflow consisted of the following main five stages: Gathers pre-conditioning and residual noise attenuation adopting the principle of amplitude preservation.Velocity building & updating using available well data, interpreted horizons and applying VTI full azimuth and multi azimuth velocity tomography processes.Depth imaging using Kirchhoff PSDM in OVT (Offset Vector Tile) domain.Post migration processing for residual inter-bed multiples & noise attenuation in addition to azimuthal anisotropy analysis and final depth-tie examination.Post stack processing for acquisition foot print removal and signal to noise ratio (S/N) enhancement.\u0000 It should be noted that the selection of the optimum processing parameters at all the processing steps was done after the implementation of an intensive testing & rigorous QC/QA procedures.\u0000 The main results and findings revealed by the 3D Anisotropic PSDM processing and the subsequent 3D seismic data interpretation are summarized as follows: PSDM shows less depth uncertainty compared to PSTM at existing wells. However, based on the results of recent drilling activities which have been conducted after PSDM, depth uncertainty at new well locations still exists.Reliable velocity model was built for depth imaging. This was established after 12 tomography iterations carried out for the isotropic velocity model and four iterations of anisotropy updates and VTI azimuthal velocity tomography.Some low relief structures are better defined in PSDM than PSTM.Seismic continuity of some target levels has been improved.Seismic resolution is degraded due to the limited frequency content.Fault imaging has been improved at some locations.","PeriodicalId":11014,"journal":{"name":"Day 1 Mon, November 12, 2018","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76987443","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 pressure response observed during the unsteady state displacement is a critical factor in determining the steady value and contains valuable characteristics about the rock permeability and capillary pressure. Our objective is to elucidate the mechanism of the unsteady state displcment and its impact on the pressure reponse. We tried to match the experimentally-measured pressure profile using both numerical simulation and analytical solutions. Promising results are observed when the capillary pressure is considered. The results clarify that this response is not a function of gas compressibility or viscous fingering, but is directly linked to the ratio of liquid fractional flow to liquid relative permeability as a function of saturation. The relative permeability exponents have a direct role to play in this regard. This work highlights the inacpaibility observed in a reservoir simulator to capture the pressure signature. This brings into question the ability of such simulators to provide reliable data when it comes to model the displacement processes at the core-scale.
{"title":"On the Pressure Response During Unsteady State Fluid Displacement Experiments","authors":"M. Mehana, M. Fahes","doi":"10.2118/193299-MS","DOIUrl":"https://doi.org/10.2118/193299-MS","url":null,"abstract":"\u0000 The pressure response observed during the unsteady state displacement is a critical factor in determining the steady value and contains valuable characteristics about the rock permeability and capillary pressure. Our objective is to elucidate the mechanism of the unsteady state displcment and its impact on the pressure reponse. We tried to match the experimentally-measured pressure profile using both numerical simulation and analytical solutions. Promising results are observed when the capillary pressure is considered. The results clarify that this response is not a function of gas compressibility or viscous fingering, but is directly linked to the ratio of liquid fractional flow to liquid relative permeability as a function of saturation. The relative permeability exponents have a direct role to play in this regard. This work highlights the inacpaibility observed in a reservoir simulator to capture the pressure signature. This brings into question the ability of such simulators to provide reliable data when it comes to model the displacement processes at the core-scale.","PeriodicalId":11014,"journal":{"name":"Day 1 Mon, November 12, 2018","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82864295","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}
During normal rig workover operations, once the old completion is retrieved, corrosion log is being executed to check the condition of the casing and/or liner as one of the means to establish a way forward. Decision can be made easily in case of pipe found completely corroded or absolutely intact. However, such clear scenarios are not always the case and the decision making takes significant time, specially if corrosion log results are received at night time or during the week end. It may become a subject of hot discussion between involved stakeholders, trying to find a right balance between safety and operations. Therefore Gas Development Operations Subsurface Team of ADNOC Onshore requested Technical Center Well Integrity Team to identify clear criteria in advance, to save rig time and improve business performance and decision making process. Based on this request Technical Center developed a strategy of predefined well integrity criteria's that are being successfully used now, saving rig time during workover and avoiding conflicts between teams in questionable situations. The method is based on several factors: Maximum Allowable Annulus Surface Pressure (MAASP) calculation as per Norsok D10 standard, application of Double Barrier concept for Secondary Well Barrier Envelope, sensitivity analysis based on MAASP degradation and remained wall thickness of casing and/or liner. This method has already been successfully implemented in several wells during workover operations saving time for decision making. It is planned to be included in the next release of corporate procedures. Method, explained in this paper can be used as a guideline by all petroleum engineers, drilling engineers, well integrity engineers and petrophysicists who are involved in workover operations, helping them to improve decision making process based on the results of the casing corrosion logs. In addition, the subject of well life prediction and well life extension in standard Company well design is covered, with focus on safety during workover operations.
{"title":"Rig Time Optimization During Workover by Predefined Well Integrity Criteria Using MAASP Sensitivity Analysis","authors":"A. Yugay, Fawad Zain Yousfi, A. Jaiyeola","doi":"10.2118/192924-MS","DOIUrl":"https://doi.org/10.2118/192924-MS","url":null,"abstract":"\u0000 During normal rig workover operations, once the old completion is retrieved, corrosion log is being executed to check the condition of the casing and/or liner as one of the means to establish a way forward. Decision can be made easily in case of pipe found completely corroded or absolutely intact. However, such clear scenarios are not always the case and the decision making takes significant time, specially if corrosion log results are received at night time or during the week end. It may become a subject of hot discussion between involved stakeholders, trying to find a right balance between safety and operations. Therefore Gas Development Operations Subsurface Team of ADNOC Onshore requested Technical Center Well Integrity Team to identify clear criteria in advance, to save rig time and improve business performance and decision making process. Based on this request Technical Center developed a strategy of predefined well integrity criteria's that are being successfully used now, saving rig time during workover and avoiding conflicts between teams in questionable situations.\u0000 The method is based on several factors: Maximum Allowable Annulus Surface Pressure (MAASP) calculation as per Norsok D10 standard, application of Double Barrier concept for Secondary Well Barrier Envelope, sensitivity analysis based on MAASP degradation and remained wall thickness of casing and/or liner. This method has already been successfully implemented in several wells during workover operations saving time for decision making. It is planned to be included in the next release of corporate procedures.\u0000 Method, explained in this paper can be used as a guideline by all petroleum engineers, drilling engineers, well integrity engineers and petrophysicists who are involved in workover operations, helping them to improve decision making process based on the results of the casing corrosion logs. In addition, the subject of well life prediction and well life extension in standard Company well design is covered, with focus on safety during workover operations.","PeriodicalId":11014,"journal":{"name":"Day 1 Mon, November 12, 2018","volume":"51 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78832972","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. Salahuddin, Sheikha Al Naqbi, S. Syofyan, M. Y. Alklih, K. Hammadi
Reservoir compartmentalization, either structural, stratigraphic, or combination, is one of key parameters for accurately characterizing the hydrocarbons distribution in the subsurface and it is an important component for optimizing hydrocarbon recovery. In order to accurately characterize its compartmentalization, structural synthesis has been applied for generating a representative structural configuration of the complex and highly faulted reservoirs of the studied field. This paper demonstrates detail structural synthesis of a Cretaceous Middle-Eastern carbonate reservoir. The studied field exhibits multiple fault blocks with different fluid composition and contacts variation. Log analysis and test results from a number of wells suggested oil rim with significant gas cap and water leg. Exploiting the oil and gas in highly faulted reservoir possesses a major challenge hence the optimum strategy of development plan was created. Multi-tectonics history of the Arabia in the region is demonstrated by both folding and brittle deformation represented by fault system comprising en echelon faults and joint sets. The most dominant faults are N75W and N45W trending strike slip fault systems. Kinematic analysis, outcrop analogue, and nearby field analogue revealed that the two fault systems have been developed by different tectonic events. The N75W trending faults have been developed as tensile fracture shortly prior to folding when SHmax azimuth was approximately oriented 120o azimuth. The N45W trending faults have been developed at a later stage possible as splay faults by branching from the pre-existing N75W when the SHmax trend was oriented approximately 90°. The N45W fault arrays show partitioning of displacement between the various splays, with relatively abrupt changes in the displacement at branchlines. Long ‘single faults’ are frequently shown to be segmented into en-echelon arrays. This expression defines a model of fault growth by radial propagation and linkage from a single seed fault as indicated from geometrical and kinematic evidence. Antithetic N45W fault exhibit a downward decrease in displacement towards a tip line near the N75W master fault. This suggests that the N45W faults were initially developed as Riedel shears which then propagated and linked to the pre-existing N75W system as splay faults. This has occurred by a continuous counterclockwise rotation of the causative SHmax stress from Cretaceous to present. Quantification of the orientations, segmentation, and offset magnitudes provided a foundation for defining their implications for fluid charging, fluid flow, and pressure development within the reservoir. Thus several development scenarios were constructed in order to maintain the pressure and production rate, considering various combinations of horizontal producers and injectors, number of wells, well orientation, horizontal length, and depletion schemes.
{"title":"Heavily Compartmentalized Reservoir: From Structural Synthesis to Optimum Development Plan","authors":"A. Salahuddin, Sheikha Al Naqbi, S. Syofyan, M. Y. Alklih, K. Hammadi","doi":"10.2118/193136-MS","DOIUrl":"https://doi.org/10.2118/193136-MS","url":null,"abstract":"\u0000 Reservoir compartmentalization, either structural, stratigraphic, or combination, is one of key parameters for accurately characterizing the hydrocarbons distribution in the subsurface and it is an important component for optimizing hydrocarbon recovery. In order to accurately characterize its compartmentalization, structural synthesis has been applied for generating a representative structural configuration of the complex and highly faulted reservoirs of the studied field. This paper demonstrates detail structural synthesis of a Cretaceous Middle-Eastern carbonate reservoir. The studied field exhibits multiple fault blocks with different fluid composition and contacts variation. Log analysis and test results from a number of wells suggested oil rim with significant gas cap and water leg. Exploiting the oil and gas in highly faulted reservoir possesses a major challenge hence the optimum strategy of development plan was created.\u0000 Multi-tectonics history of the Arabia in the region is demonstrated by both folding and brittle deformation represented by fault system comprising en echelon faults and joint sets. The most dominant faults are N75W and N45W trending strike slip fault systems. Kinematic analysis, outcrop analogue, and nearby field analogue revealed that the two fault systems have been developed by different tectonic events. The N75W trending faults have been developed as tensile fracture shortly prior to folding when SHmax azimuth was approximately oriented 120o azimuth. The N45W trending faults have been developed at a later stage possible as splay faults by branching from the pre-existing N75W when the SHmax trend was oriented approximately 90°.\u0000 The N45W fault arrays show partitioning of displacement between the various splays, with relatively abrupt changes in the displacement at branchlines. Long ‘single faults’ are frequently shown to be segmented into en-echelon arrays. This expression defines a model of fault growth by radial propagation and linkage from a single seed fault as indicated from geometrical and kinematic evidence. Antithetic N45W fault exhibit a downward decrease in displacement towards a tip line near the N75W master fault. This suggests that the N45W faults were initially developed as Riedel shears which then propagated and linked to the pre-existing N75W system as splay faults. This has occurred by a continuous counterclockwise rotation of the causative SHmax stress from Cretaceous to present.\u0000 Quantification of the orientations, segmentation, and offset magnitudes provided a foundation for defining their implications for fluid charging, fluid flow, and pressure development within the reservoir. Thus several development scenarios were constructed in order to maintain the pressure and production rate, considering various combinations of horizontal producers and injectors, number of wells, well orientation, horizontal length, and depletion schemes.","PeriodicalId":11014,"journal":{"name":"Day 1 Mon, November 12, 2018","volume":"47 7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84867635","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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