Raymond Nguyen, A. Jacques, V. Jaffrezic, Y. Bigno, A. Serry, H. Zakaria, O. Khan, O. Jadallah, B. Brouard
The development of carbonate reservoirs of a giant field, Offshore Abu Dhabi, requires long horizontal wells to maximize productivity, but at the risk of unwanted gas and water channeling through its inherent heterogeneities. Conformance can be enhanced with dedicated segmented completions (blank sections, Inflow Control Device, Autonomous Inflow Control Device, etc.) or selective acid stimulation (diverter, Limited Entry Liner), which are increasingly implemented to extend well life, and eventually well value. If these technologies have matured, success depends heavily on the quality of the formation knowledge prior to completion. As of today, conventional logs provide the basic ground, but they lack dynamic information, whereas production logging results are obtained too late, when the well is already completed. Initially introduced for the optimization of unconventional well completions (see Jacques et al, URTEC 2019), the Well Testing Logging (WTLog) offers the advantage to record a log of mobility, at the end of drilling the openhole, enabling a favorable timing to influence adapted completion and stimulation design. Contrasted viscosity brines are sequentially circulated through the drill pipes at a constant rate and back-produced from the casing at constant pressure. The fluids interface travels in the drain from the TD to the casing shoe, and the measurement of the differential formation seepage is interpreted into an injectivity profile. Combined with rate fall-off phase analysis, permeability and skin logs are derived. Lasting a few hours and realized with conventional rig equipment (such as cement pumps, coriolis flowmeters, Managed Pressure Drilling system), it is a nonintrusive, safe, and ultimately low-cost operation. Forward, it can replace costly logging, when aimed at characterizing heterogeneities. Within a year, the two first WTLog pilots of the Middle East were successfully designed and carried out. They targeted two appraisal wells in distinct undeveloped reservoirs (Cretaceous and Upper Jurassic formations) which benefited from rich acquisition programs (Image log, Production log) to benchmark and qualify this technology. After an explanation of the technology principles, this paper describes the design, operations, and results of these pilots. It then focuses on the petrophysical consolidation of the matrix/fracture characterization. It concludes by sharing the learnings and offers insight to what extent it is a promising technology to be applied in Middle East carbonate reservoir developments.
阿布扎比近海(Offshore Abu Dhabi)一个大型油气田的碳酸盐岩储层开发需要长水平井来实现产能最大化，但由于其固有的非均质性，存在不必要的气和水窜流风险。可以通过专用分段完井(空白段、流入控制装置、自动流入控制装置等)或选择性酸增产(转向剂、有限进入尾管)来提高井眼的稳定性，这些措施越来越多地用于延长井的寿命，最终提高井的价值。如果这些技术已经成熟，成功与否在很大程度上取决于完井前地层知识的质量。目前，常规测井提供了基本的基础信息，但缺乏动态信息，而生产测井结果在井已经完井后才得到。测试测井(WTLog)最初是为了优化非常规井完井(见Jacques等人，URTEC 2019)而引入的，它的优点是可以在裸眼钻井结束时记录井的流动情况，从而为完井和增产设计提供有利的时机。对比粘度盐水依次以恒定速率通过钻杆循环，并在恒定压力下从套管中回排。流体界面在从TD到套管鞋的排液中流动，对地层微分渗流的测量被解释为注入能力剖面。结合速率降相分析，导出了渗透率和表皮测井曲线。使用常规钻机设备(如水泥泵、科里奥利流量计、控压钻井系统)，作业时间仅为几个小时，是一种非侵入式、安全、低成本的作业。向前，它可以取代昂贵的日志记录，当目标是表征异构性。在一年内，中东地区的两个首批WTLog飞行员成功设计并实施。他们将两口评价井定位于不同的未开发油藏(白垩纪和上侏罗统地层)，这些井受益于丰富的采集程序(图像测井、生产测井)，以对该技术进行基准测试和验证。在阐述了技术原理后，本文描述了这些试点的设计、操作和结果。然后重点关注基质的岩石物理固结/裂缝表征。最后，本文分享了该技术在中东碳酸盐岩储层开发中的应用前景。
{"title":"Piloting the 1st Well-Test-Logging in the Middle East, Paving the Way to Low-Cost Dynamic Reservoir Characterization and Well Value Optimization","authors":"Raymond Nguyen, A. Jacques, V. Jaffrezic, Y. Bigno, A. Serry, H. Zakaria, O. Khan, O. Jadallah, B. Brouard","doi":"10.2118/206177-ms","DOIUrl":"https://doi.org/10.2118/206177-ms","url":null,"abstract":"\u0000 The development of carbonate reservoirs of a giant field, Offshore Abu Dhabi, requires long horizontal wells to maximize productivity, but at the risk of unwanted gas and water channeling through its inherent heterogeneities. Conformance can be enhanced with dedicated segmented completions (blank sections, Inflow Control Device, Autonomous Inflow Control Device, etc.) or selective acid stimulation (diverter, Limited Entry Liner), which are increasingly implemented to extend well life, and eventually well value.\u0000 If these technologies have matured, success depends heavily on the quality of the formation knowledge prior to completion. As of today, conventional logs provide the basic ground, but they lack dynamic information, whereas production logging results are obtained too late, when the well is already completed.\u0000 Initially introduced for the optimization of unconventional well completions (see Jacques et al, URTEC 2019), the Well Testing Logging (WTLog) offers the advantage to record a log of mobility, at the end of drilling the openhole, enabling a favorable timing to influence adapted completion and stimulation design. Contrasted viscosity brines are sequentially circulated through the drill pipes at a constant rate and back-produced from the casing at constant pressure. The fluids interface travels in the drain from the TD to the casing shoe, and the measurement of the differential formation seepage is interpreted into an injectivity profile. Combined with rate fall-off phase analysis, permeability and skin logs are derived. Lasting a few hours and realized with conventional rig equipment (such as cement pumps, coriolis flowmeters, Managed Pressure Drilling system), it is a nonintrusive, safe, and ultimately low-cost operation. Forward, it can replace costly logging, when aimed at characterizing heterogeneities.\u0000 Within a year, the two first WTLog pilots of the Middle East were successfully designed and carried out. They targeted two appraisal wells in distinct undeveloped reservoirs (Cretaceous and Upper Jurassic formations) which benefited from rich acquisition programs (Image log, Production log) to benchmark and qualify this technology.\u0000 After an explanation of the technology principles, this paper describes the design, operations, and results of these pilots. It then focuses on the petrophysical consolidation of the matrix/fracture characterization. It concludes by sharing the learnings and offers insight to what extent it is a promising technology to be applied in Middle East carbonate reservoir developments.","PeriodicalId":10965,"journal":{"name":"Day 3 Thu, September 23, 2021","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88353951","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}
It is useful during drilling operations to know when bit failure has occurred because this knowledge can be used to improve drilling performance and provides guidance on when to pull out of hole. This paper presents a simple polycrystalline diamond compact (PDC) bit wear indicator and an associated methodology to help quantify wear and failure using real-time surface sensor data and PDC dull images. The wear indicator is used to identify the point of failure, after which corresponding surface data and dull images can be used to infer the cause of failure. It links rotary speed (RPM) with rate of penetration (ROP) and weight-on-bit (WOB). The term incorporating RPM and ROP represents a "sliding distance", i.e. the number of revolutions required to drill a unit distance of formation, while the WOB represents the formation hardness or contact pressure applied by the formation. This PDC bit wear metric was applied and validated on a data set comprised of 51 lateral production hole bit runs on 9 wells. Surface electric drilling recorder (EDR) data alongside bit dull photos were used to interpret the relationship between the wear metric and observed PDC wear. All runs were in the same extremely hard (estimated 35 – 50 kpsi unconfined compressive strength) and abrasive shale formation. Sliding drilling time and off-bottom time were filtered from the data, and the median wear metric value for each stand was calculated versus measured hole depth while in rotary mode. The initial point in time when the bit fails was found to be most often a singular event, after which ROP never recovered. Once damaged, subsequent catastrophic bit failure generally occurred within drilling 1-2 stands. The rapid bit failure observed was attributed to the increased thermal loads seen at the wear flat of the PDC cutter, which accelerate diamond degradation. The wear metric more accurately identifies the point in time (stand being drilled) of failure than the ROP value by itself. Review of post-run PDC photos show that the final recorded wear metric value can be related to the observed severity of the PDC damage. This information was used to determine a pull criterion to reduce pulling bits that are damaged beyond repair (DBR) and reduce time spent beyond the effective end of life. Pulling bits before DBR status is reached and replacing them increases overall drilling performance. The presented wear metric is simple and cost-effective to implement, which is important to lower-cost land wells, and requires only real-time surface sensor data. It enables a targeted approach to analyzing PDC bit wear, optimizing drilling performance and establishing effective bit pull criteria.
{"title":"Quantifying PDC Bit Wear in Real-Time and Establishing an Effective Bit Pull Criterion Using Surface Sensors","authors":"Y. Witt-Doerring, P. Pastusek, P. Ashok, E. Oort","doi":"10.2118/205844-ms","DOIUrl":"https://doi.org/10.2118/205844-ms","url":null,"abstract":"\u0000 It is useful during drilling operations to know when bit failure has occurred because this knowledge can be used to improve drilling performance and provides guidance on when to pull out of hole. This paper presents a simple polycrystalline diamond compact (PDC) bit wear indicator and an associated methodology to help quantify wear and failure using real-time surface sensor data and PDC dull images.\u0000 The wear indicator is used to identify the point of failure, after which corresponding surface data and dull images can be used to infer the cause of failure. It links rotary speed (RPM) with rate of penetration (ROP) and weight-on-bit (WOB). The term incorporating RPM and ROP represents a \"sliding distance\", i.e. the number of revolutions required to drill a unit distance of formation, while the WOB represents the formation hardness or contact pressure applied by the formation.\u0000 This PDC bit wear metric was applied and validated on a data set comprised of 51 lateral production hole bit runs on 9 wells. Surface electric drilling recorder (EDR) data alongside bit dull photos were used to interpret the relationship between the wear metric and observed PDC wear. All runs were in the same extremely hard (estimated 35 – 50 kpsi unconfined compressive strength) and abrasive shale formation. Sliding drilling time and off-bottom time were filtered from the data, and the median wear metric value for each stand was calculated versus measured hole depth while in rotary mode.\u0000 The initial point in time when the bit fails was found to be most often a singular event, after which ROP never recovered. Once damaged, subsequent catastrophic bit failure generally occurred within drilling 1-2 stands. The rapid bit failure observed was attributed to the increased thermal loads seen at the wear flat of the PDC cutter, which accelerate diamond degradation. The wear metric more accurately identifies the point in time (stand being drilled) of failure than the ROP value by itself.\u0000 Review of post-run PDC photos show that the final recorded wear metric value can be related to the observed severity of the PDC damage. This information was used to determine a pull criterion to reduce pulling bits that are damaged beyond repair (DBR) and reduce time spent beyond the effective end of life. Pulling bits before DBR status is reached and replacing them increases overall drilling performance.\u0000 The presented wear metric is simple and cost-effective to implement, which is important to lower-cost land wells, and requires only real-time surface sensor data. It enables a targeted approach to analyzing PDC bit wear, optimizing drilling performance and establishing effective bit pull criteria.","PeriodicalId":10965,"journal":{"name":"Day 3 Thu, September 23, 2021","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77673373","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}
Mihaela Vlaicu, Vasile Marius Nae, P. Buerssner, Stefan Liviu Firu, N. Logashova
Paraffin represents one of the main case of failures and production losses which facing the entire oil industry. Prevention of paraffin deposition on the subsurface/surface equipment can be achieved by keeping the paraffin dissolved in crude oil or minimizing the adhesion or aggregation process of wax crystals. The paraffin problems which occur, conduct to gradual reduction of the tubular and pipelines internal diameter, restriction or valves blockages, and reduce the equipment capacity until the production is stop. Problems due to paraffin deposition varies and is different according with each commercial field, sometime the difference is from a well to well which producing from the same reservoir with different consistency. How we shall proceed? Before or after paraffin is field on the equipment? How could be avoid the future paraffin deposition? How long the selected method is proper for well ? The decision represents a combination based on oil's chemical & physical characteristics, well's behavior, method selected for prevention or elimination and combined with economic analysis and field experience. The paraffin inhibition applying is a common practice in OMV Petrom, which cover majority of the production wells. For the special wells, which the paraffin inhibition didn't provided satisfying results (multiple intervention due to paraffin deposition) was selected the Down Hole Heating technology (DHH) which was successfully tested in our company since 2014 thanks according with the yearly New Technology Program. The operating principle consists in heating the fluid volume from tubing using the heating cable which can be installed inside tubing, for NF and ESP wells or outside tubing for SRP or PCP wells. The cable is designed and located at the interval of wax crystallization appearance and heats the fluid to the temperature higher than the wax crystallization point (WAT). Since then, the DHH technology had an upward course, proven by high run life (highest value 2500 days / average 813 days) of the technology at the total 47 wells equipped, until this moment. Based on the successful results, recorded of 64% of old production wells equipped, it was decided to apply the technology at first completion of the new wells (36%), thus ensuring the protection of the new equipment. The paper offers an overview of DHH technology implementation, achievements, benefits and online monitoring of technology implementation starting with 2014 until today. The total impact shown a decreasing of no.of failures with 73,8%, the cost of intervention with 76,5%. The production losses decreased only with 5%, which certifies the fact that the technology helping production maintaining during the exploitation in comparison with production losses due paraffin issues recorded at wells without equipped with DHH technology. During 6 years of down hole heating technology application were developed candidate selection decision tree, monitoring the electrical efficiency
{"title":"Downhole Heating Technology – New Solution for Paraffinic Wells","authors":"Mihaela Vlaicu, Vasile Marius Nae, P. Buerssner, Stefan Liviu Firu, N. Logashova","doi":"10.2118/206128-ms","DOIUrl":"https://doi.org/10.2118/206128-ms","url":null,"abstract":"\u0000 Paraffin represents one of the main case of failures and production losses which facing the entire oil industry. Prevention of paraffin deposition on the subsurface/surface equipment can be achieved by keeping the paraffin dissolved in crude oil or minimizing the adhesion or aggregation process of wax crystals. The paraffin problems which occur, conduct to gradual reduction of the tubular and pipelines internal diameter, restriction or valves blockages, and reduce the equipment capacity until the production is stop. Problems due to paraffin deposition varies and is different according with each commercial field, sometime the difference is from a well to well which producing from the same reservoir with different consistency.\u0000 How we shall proceed? Before or after paraffin is field on the equipment? How could be avoid the future paraffin deposition? How long the selected method is proper for well ? The decision represents a combination based on oil's chemical & physical characteristics, well's behavior, method selected for prevention or elimination and combined with economic analysis and field experience.\u0000 The paraffin inhibition applying is a common practice in OMV Petrom, which cover majority of the production wells. For the special wells, which the paraffin inhibition didn't provided satisfying results (multiple intervention due to paraffin deposition) was selected the Down Hole Heating technology (DHH) which was successfully tested in our company since 2014 thanks according with the yearly New Technology Program. The operating principle consists in heating the fluid volume from tubing using the heating cable which can be installed inside tubing, for NF and ESP wells or outside tubing for SRP or PCP wells. The cable is designed and located at the interval of wax crystallization appearance and heats the fluid to the temperature higher than the wax crystallization point (WAT).\u0000 Since then, the DHH technology had an upward course, proven by high run life (highest value 2500 days / average 813 days) of the technology at the total 47 wells equipped, until this moment.\u0000 Based on the successful results, recorded of 64% of old production wells equipped, it was decided to apply the technology at first completion of the new wells (36%), thus ensuring the protection of the new equipment.\u0000 The paper offers an overview of DHH technology implementation, achievements, benefits and online monitoring of technology implementation starting with 2014 until today. The total impact shown a decreasing of no.of failures with 73,8%, the cost of intervention with 76,5%. The production losses decreased only with 5%, which certifies the fact that the technology helping production maintaining during the exploitation in comparison with production losses due paraffin issues recorded at wells without equipped with DHH technology.\u0000 During 6 years of down hole heating technology application were developed candidate selection decision tree, monitoring the electrical efficiency","PeriodicalId":10965,"journal":{"name":"Day 3 Thu, September 23, 2021","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73417033","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}
P. Ferrara, Luigi Mutidieri, Gianluca Magni, D. Farina, Luca Dal Forno, Giorgio Ricci Maccarini, Francesco Battaglia, G. Ricci
In an era of reduced profit margin and high market uncertainty, more than ever it is important to meet operational excellence as a key factor for business sustainability. This is common to most technical applications, but it is particularly true for the drilling operations, where considerable investments and associated risks are involved. During last four years, as part of its digital transformation process, Eni has equipped itself with several digital tools for the diagnosis and the monitoring of drilling and completion operations. Goals and reached benefits can be summarized in risk reduction, operational efficiency and performance optimization. Based on a wide case history started in 2019, a Digital Drilling Package was developed for operations support, from the design to the construction phase. Three main tools are now available to be applied to the most complex wells, either stand-alone or in parallel, covering drilling operations non-productive time (NPT) prediction, performance advanced analytics and real time simulations. This last simulation tool was deployed for the first time in late 2020 on some wells and is now being included in the engineering and operation workflows. Attacking operational NPT and invisible lost time with the aim to increase safety and to reach the technical limit is not only a matter of processing tools. It requires a deep integration with headquarter (HQ), geographical units and field locations, with the definition of a strong data management infrastructure. This paper describes Eni's experience both on-site and in office, showing how the portability and integration of big data systems, suitable data lake architectures and human factor synergies can create effectiveness at all levels. An Africa Offshore field case history is reported to show how predictive and data analytics modelling and tools interact. In addition, the way in which these tools have been managed to support optimum decision-making processes is highlighted. Next development steps will target an even higher level of integration of all available digital tools to have a single diagnostic approach based on univocal dashboards and in-house data server infrastructures.
{"title":"First Complete Digital Drilling Package Deployment for Risks Reduction and Performance Optimization: Africa Offshore Case History","authors":"P. Ferrara, Luigi Mutidieri, Gianluca Magni, D. Farina, Luca Dal Forno, Giorgio Ricci Maccarini, Francesco Battaglia, G. Ricci","doi":"10.2118/205924-ms","DOIUrl":"https://doi.org/10.2118/205924-ms","url":null,"abstract":"\u0000 In an era of reduced profit margin and high market uncertainty, more than ever it is important to meet operational excellence as a key factor for business sustainability. This is common to most technical applications, but it is particularly true for the drilling operations, where considerable investments and associated risks are involved. During last four years, as part of its digital transformation process, Eni has equipped itself with several digital tools for the diagnosis and the monitoring of drilling and completion operations. Goals and reached benefits can be summarized in risk reduction, operational efficiency and performance optimization.\u0000 Based on a wide case history started in 2019, a Digital Drilling Package was developed for operations support, from the design to the construction phase. Three main tools are now available to be applied to the most complex wells, either stand-alone or in parallel, covering drilling operations non-productive time (NPT) prediction, performance advanced analytics and real time simulations. This last simulation tool was deployed for the first time in late 2020 on some wells and is now being included in the engineering and operation workflows.\u0000 Attacking operational NPT and invisible lost time with the aim to increase safety and to reach the technical limit is not only a matter of processing tools. It requires a deep integration with headquarter (HQ), geographical units and field locations, with the definition of a strong data management infrastructure. This paper describes Eni's experience both on-site and in office, showing how the portability and integration of big data systems, suitable data lake architectures and human factor synergies can create effectiveness at all levels. An Africa Offshore field case history is reported to show how predictive and data analytics modelling and tools interact. In addition, the way in which these tools have been managed to support optimum decision-making processes is highlighted.\u0000 Next development steps will target an even higher level of integration of all available digital tools to have a single diagnostic approach based on univocal dashboards and in-house data server infrastructures.","PeriodicalId":10965,"journal":{"name":"Day 3 Thu, September 23, 2021","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75329475","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}
E. Papamichos, L. E. Walle, A. Berntsen, D. Szewczyk
Sand onset and sand rate predictions are important in hydrocarbon production to optimize production, increase recovery, and reduce costs and the environmental footprint. Recent laboratory results on Castlegate sandstone from sand production tests in a True Triaxial test system have revealed that stress anisotropy plays an important role not only on sand onset but also in sand rate. The results confirmed our hypothesis that stress anisotropy means earlier sand produced but less sand. The laboratory results also revealed the effect of fluid saturation, i.e., oil, brine or irreducible water saturation on sand onset and sand rate. They allow the calibration of SandPredictor, a field sand prediction model, for stress anisotropy and production before and after water breakthrough. A field case analysis demonstrated the effects and showed the importance of in situ stress anisotropy and watercut on sand mass and rate.
{"title":"Sand Mass Production in Anisotropic Stresses From Lab to Field Predictions","authors":"E. Papamichos, L. E. Walle, A. Berntsen, D. Szewczyk","doi":"10.2118/205929-ms","DOIUrl":"https://doi.org/10.2118/205929-ms","url":null,"abstract":"\u0000 Sand onset and sand rate predictions are important in hydrocarbon production to optimize production, increase recovery, and reduce costs and the environmental footprint. Recent laboratory results on Castlegate sandstone from sand production tests in a True Triaxial test system have revealed that stress anisotropy plays an important role not only on sand onset but also in sand rate. The results confirmed our hypothesis that stress anisotropy means earlier sand produced but less sand. The laboratory results also revealed the effect of fluid saturation, i.e., oil, brine or irreducible water saturation on sand onset and sand rate. They allow the calibration of SandPredictor, a field sand prediction model, for stress anisotropy and production before and after water breakthrough. A field case analysis demonstrated the effects and showed the importance of in situ stress anisotropy and watercut on sand mass and rate.","PeriodicalId":10965,"journal":{"name":"Day 3 Thu, September 23, 2021","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75234121","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}
While optimizing hydrocarbon production, combining well intervention solutions can enable significant benefits due to reductions in risk exposure: fewer rig-ups and downs, less in-the-hole operating time and the carbon production and costs associated with rig time, especially when working from sub-sea intervention vessels. Operators in general, prefer to achieve multiple intervention objectives in a single descent in the well, if the operations complexity does not increase the risk exposure to an unacceptable level. Often, the risk of a mis-run, causing a second run, meets the cost vs value criteria for acceptable risk, when the large operating time savings of a successful combined run is considered. In collaboration with a mechanical e-line provider, North Sea operators developed three reliable combination solutions which increased their operational efficiency. Combining these most run services under more standard, common scope of work procedures, saved the operator time in planning, execution, risk exposure and money, while enabling them to produce hydrocarbons in the saved time. This paper will present the technology involved with these combined services, use a typical example of each and the cost savings achieved.
{"title":"The Case for Combining Well Intervention Solutions to Optimize Production and Reduce Risk Exposure","authors":"Eyvind Morten Meling, H. Mourani, B. Schwanitz","doi":"10.2118/205889-ms","DOIUrl":"https://doi.org/10.2118/205889-ms","url":null,"abstract":"\u0000 While optimizing hydrocarbon production, combining well intervention solutions can enable significant benefits due to reductions in risk exposure: fewer rig-ups and downs, less in-the-hole operating time and the carbon production and costs associated with rig time, especially when working from sub-sea intervention vessels. Operators in general, prefer to achieve multiple intervention objectives in a single descent in the well, if the operations complexity does not increase the risk exposure to an unacceptable level. Often, the risk of a mis-run, causing a second run, meets the cost vs value criteria for acceptable risk, when the large operating time savings of a successful combined run is considered.\u0000 In collaboration with a mechanical e-line provider, North Sea operators developed three reliable combination solutions which increased their operational efficiency. Combining these most run services under more standard, common scope of work procedures, saved the operator time in planning, execution, risk exposure and money, while enabling them to produce hydrocarbons in the saved time. This paper will present the technology involved with these combined services, use a typical example of each and the cost savings achieved.","PeriodicalId":10965,"journal":{"name":"Day 3 Thu, September 23, 2021","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73022192","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 common challenge in exploration in the North Slope of Alaska is the formation evaluation of low-permeability formations when near-wellbore damage is caused by water-based muds (WBM). This study describes the novel application of existing technology to collect high-quality hydrocarbon samples efficiently in these challenging conditions. The concept was tested with a wireline formation tester in a well with severe formation damage caused by WBM. The procedure and hardware used are discussed and an example of the effectiveness of the proposed technique is shown. Due to the unfavorable mobility ratio, WBM filtrates tends to move preferentially while attempting oil sampling in low permeability rock leading to long station times during wireline formation testing operations. To overcome this challenge, a target sampling interval was subjected to high drawdown using a 3D radial probe to move the target phase closer to the wellbore. Once hydrocarbon was detected in the fluid analyzer, the 3D radial probe was retracted, and the string repositioned to cover the same interval with a straddle packer assembly. Straddle packers provide wellbore annular space for filtrate and hydrocarbon to segregate after the flow period is resumed. When hydrocarbons are again seen in the fluid analyzer, a simultaneous two-pump flow is used to collect them and discard the filtrate. The combination of 3D radial probe and straddle packer assists with displacing the mud filtrate, bringing the target hydrocarbons to the wellbore, and enables the collection of segregated samples with exceptional quality. After pumping at one sampling station using the 3D Radial probe, the maximum hydrocarbon fraction observed was 5%. When the straddle packer was positioned at the same interval, the fluid analyzer showed that the low velocity in the annular space between tool's mandrel and wellbore enabled hydrocarbon segregation from the filtrate due to the existing density contrast. When the hydrocarbon in the wellbore reached the straddle packer inlet, the lower pump was used to flow most of the filtrate in the down direction at high rate. Meanwhile, the hydrocarbon was "skimmed off" and placed in sample containers at a much lower rate using the upper pump. Laboratory results confirmed that the samples collected with the traditional sampling method contained 95% filtrate whereas the samples collected with our technique contained 90% hydrocarbon. Downhole fluid segregation using single-inlet, wireline straddle packer and dual-pump action has not been found in the literature. Recent developments in wireline formation testing use dual inlets in straddle packer modules to enable downhole segregation. We consider that the technique described here innovatively uses the capabilities of current formation testers to collect high-quality hydrocarbon samples in low permeability conditions. With minor adjustments, this technique can also be applied in gas or water sampling in wells drilled with oil-bas
{"title":"Application of Gravity-Assisted Wellbore Segregation to Wireline Sampling Operations. A Low Permeability Case Study","authors":"G. Garcia, H. Dumont, T. Akindipe","doi":"10.2118/206138-ms","DOIUrl":"https://doi.org/10.2118/206138-ms","url":null,"abstract":"\u0000 A common challenge in exploration in the North Slope of Alaska is the formation evaluation of low-permeability formations when near-wellbore damage is caused by water-based muds (WBM). This study describes the novel application of existing technology to collect high-quality hydrocarbon samples efficiently in these challenging conditions. The concept was tested with a wireline formation tester in a well with severe formation damage caused by WBM. The procedure and hardware used are discussed and an example of the effectiveness of the proposed technique is shown.\u0000 Due to the unfavorable mobility ratio, WBM filtrates tends to move preferentially while attempting oil sampling in low permeability rock leading to long station times during wireline formation testing operations. To overcome this challenge, a target sampling interval was subjected to high drawdown using a 3D radial probe to move the target phase closer to the wellbore. Once hydrocarbon was detected in the fluid analyzer, the 3D radial probe was retracted, and the string repositioned to cover the same interval with a straddle packer assembly. Straddle packers provide wellbore annular space for filtrate and hydrocarbon to segregate after the flow period is resumed. When hydrocarbons are again seen in the fluid analyzer, a simultaneous two-pump flow is used to collect them and discard the filtrate. The combination of 3D radial probe and straddle packer assists with displacing the mud filtrate, bringing the target hydrocarbons to the wellbore, and enables the collection of segregated samples with exceptional quality.\u0000 After pumping at one sampling station using the 3D Radial probe, the maximum hydrocarbon fraction observed was 5%. When the straddle packer was positioned at the same interval, the fluid analyzer showed that the low velocity in the annular space between tool's mandrel and wellbore enabled hydrocarbon segregation from the filtrate due to the existing density contrast. When the hydrocarbon in the wellbore reached the straddle packer inlet, the lower pump was used to flow most of the filtrate in the down direction at high rate. Meanwhile, the hydrocarbon was \"skimmed off\" and placed in sample containers at a much lower rate using the upper pump. Laboratory results confirmed that the samples collected with the traditional sampling method contained 95% filtrate whereas the samples collected with our technique contained 90% hydrocarbon.\u0000 Downhole fluid segregation using single-inlet, wireline straddle packer and dual-pump action has not been found in the literature. Recent developments in wireline formation testing use dual inlets in straddle packer modules to enable downhole segregation. We consider that the technique described here innovatively uses the capabilities of current formation testers to collect high-quality hydrocarbon samples in low permeability conditions. With minor adjustments, this technique can also be applied in gas or water sampling in wells drilled with oil-bas","PeriodicalId":10965,"journal":{"name":"Day 3 Thu, September 23, 2021","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74578218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Mata, Zunerge Guevara, L. Quintero, Carlos Vasquez, Hernando Trujillo, Alberto Muñoz, J. Falla
Although leakages in well tubulars have always existed, their occurrence has become very frequent as the number of active wells in mature fields increases. The catastrophic risk of these leaks is an increase in the number of environmental accidents in the oil and gas industry. One of the fundamental causes of leaks is corrosion, which plays a negative role in the productive life of the wells. Generally, these environmental events are associated with surface or near-surface sources. Since multiple casing strings exist within this depth range, the identification of the leak location becomes extremely difficult. In view of this, the industry has put much effort in improving and new technology to be more precise and comprehensive in diagnosing these leaks. The evolution of two of such technologies will be addressed in this paper. The first one is a new electromagnetic high-definition frequency tool for pipes and multiples casing for metal loss detection. This state-of-the-art technology is a noticeable improvement over existing tools, due to an important increase in the number of sources, number of detectors and wide range of working frequencies. The combination of these changes allows for the evaluation of metal loss in up to 5 concentric casings in a single run. Furthermore, the tool is small in diameter which makes it compatible with production pipes without the need of a workover rig. This versatility obviously helps in the preworkover diagnosis before deciding to move a rig to location to eventually remedy any leak problems. The electromagnetic technology is complemented, with the latest leak detection acoustic technology. A spontaneous audio source is normally associated with downhole fluid movements. The tool has an array of 8 hydrophones with a working frequency range from 100 Hz to 100 KHz. These two different technologies based on independent fundamental principles, allows for the detection of leaks in multiple concentric pipes with great vertical and radial precision to identify the exact location of leaks as small as to 0.02 L/min. the depth of investigation of the system is up to 10 feet. Therefore, it is possible to detect fluid movement within the formation. Pulsed neutron technology was included in the study to detect water movement behind the casing to establish the flow path to the surface in addition to the leak point. A very complex acquisition program was established that was undoubtedly a key success factor in the results obtained. The electromagnetic tool determined the depth of severe casing metal loss in 7-inch casing, also the acoustic tool detected the noise of fluid movement in the 7-inch annulus, and the pulsed-neutron tool showed the beginning of water movement at the same interval the temperature log, also included in the same tool string showed a considerable change that correlated with all these logs, indicating the point of communication in this well. After establishing the uniqueness of the solution, this dia
{"title":"Combination of New Acoustic and Electromagnetic Frequency Technologies Detects Leaks Behind Multiple Casings. Case History","authors":"J. Mata, Zunerge Guevara, L. Quintero, Carlos Vasquez, Hernando Trujillo, Alberto Muñoz, J. Falla","doi":"10.2118/206383-ms","DOIUrl":"https://doi.org/10.2118/206383-ms","url":null,"abstract":"\u0000 Although leakages in well tubulars have always existed, their occurrence has become very frequent as the number of active wells in mature fields increases. The catastrophic risk of these leaks is an increase in the number of environmental accidents in the oil and gas industry. One of the fundamental causes of leaks is corrosion, which plays a negative role in the productive life of the wells.\u0000 Generally, these environmental events are associated with surface or near-surface sources. Since multiple casing strings exist within this depth range, the identification of the leak location becomes extremely difficult. In view of this, the industry has put much effort in improving and new technology to be more precise and comprehensive in diagnosing these leaks. The evolution of two of such technologies will be addressed in this paper. The first one is a new electromagnetic high-definition frequency tool for pipes and multiples casing for metal loss detection. This state-of-the-art technology is a noticeable improvement over existing tools, due to an important increase in the number of sources, number of detectors and wide range of working frequencies. The combination of these changes allows for the evaluation of metal loss in up to 5 concentric casings in a single run. Furthermore, the tool is small in diameter which makes it compatible with production pipes without the need of a workover rig. This versatility obviously helps in the preworkover diagnosis before deciding to move a rig to location to eventually remedy any leak problems.\u0000 The electromagnetic technology is complemented, with the latest leak detection acoustic technology. A spontaneous audio source is normally associated with downhole fluid movements. The tool has an array of 8 hydrophones with a working frequency range from 100 Hz to 100 KHz. These two different technologies based on independent fundamental principles, allows for the detection of leaks in multiple concentric pipes with great vertical and radial precision to identify the exact location of leaks as small as to 0.02 L/min. the depth of investigation of the system is up to 10 feet. Therefore, it is possible to detect fluid movement within the formation.\u0000 Pulsed neutron technology was included in the study to detect water movement behind the casing to establish the flow path to the surface in addition to the leak point.\u0000 A very complex acquisition program was established that was undoubtedly a key success factor in the results obtained. The electromagnetic tool determined the depth of severe casing metal loss in 7-inch casing, also the acoustic tool detected the noise of fluid movement in the 7-inch annulus, and the pulsed-neutron tool showed the beginning of water movement at the same interval the temperature log, also included in the same tool string showed a considerable change that correlated with all these logs, indicating the point of communication in this well.\u0000 After establishing the uniqueness of the solution, this dia","PeriodicalId":10965,"journal":{"name":"Day 3 Thu, September 23, 2021","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76223984","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. Donald, J. Patrick, Stribling K. Michelle, Craig Jim, R. Luiz, Silva Pedro, S. A. Ibrahim
While the shale revolution flourished prior to the pandemic, the increased supply bubble had already taken a toll on the profitability of horizontal wells with multiple transverse fractures. A significant shift previously occurred to reduce proppant costs by utilizing cheaper, smaller grained, lower strength, and broadly diverse grain sized sands. Due to the extremely low matrix permeability in active unconventional plays, the use of regional 40/70 and 100 mesh sands (50/140, 70/140, etc.) has become commonplace with adequate results. What remains is the need for enhanced conductivity near the wellbore to handle the radial flow convergence loss when the well is brought on-line. Research is being conducted to better understand how to efficiently increase near-wellbore conductivity using lead and tail-in stages with higher permeability (ceramic) proppant when frac sand is the majority of the material pumped into the well. A 10’x20’ Large Slot Flow (LSF) apparatus, equipped with multiple injection points, side-panel ports for leak-off and/or post-test injection, with the ability to be disassembled for sample analysis after testing, was utilized for this project. For this data, the inlet was moved to the centerline of the wall to allow for proppant and fluid to transport into an environment similar to a horizontal wellbore connecting with a transverse fracture. Various tests were conducted to study the depositional characteristics of lead and tail-in stages with ceramic proppant (15% BW-Lead, 5% BW-Tail) and a main stage of 100 mesh sand (80%). Three inlet positions were established in the lower, middle, and upper portion of the apparatus. Tests were recorded to visually capture the efficiency of placing the premium proppants near the wellbore for increased conductivity. A key addition to the study was the innovative, post-production analysis through the side-panel ports. Fluid was injected into the proppant pack to observe the effect of increased near-wellbore conductivity. To improve visibility, the fluid was colored with a fluorescent dye and observed under black lights. The injection front geometry was radial initially, but typically elongated toward the exit point after contacting the ceramic proppant. The amount of time and distance for the fluid to travel through the sand pack, as well as that for the fluid to reach the offtake point once the ceramic bed was reached, were monitored and recorded. The ratio of the velocities should represent a valid qualitative indication of the conductivity contrast of the two proppants. This paper will describe the unique experimental configuration, outline the testing program for both deposition and post-production assessments performed on the deposits, along with results that could provide better design practices leading to improved transverse fracture performance.
{"title":"An Advanced Proppant Depositional Study with Post-Production Flow Evaluation in a 10' X 20', Transverse Fracture, Slot Flow Configuration","authors":"A. Donald, J. Patrick, Stribling K. Michelle, Craig Jim, R. Luiz, Silva Pedro, S. A. Ibrahim","doi":"10.2118/206212-ms","DOIUrl":"https://doi.org/10.2118/206212-ms","url":null,"abstract":"\u0000 While the shale revolution flourished prior to the pandemic, the increased supply bubble had already taken a toll on the profitability of horizontal wells with multiple transverse fractures. A significant shift previously occurred to reduce proppant costs by utilizing cheaper, smaller grained, lower strength, and broadly diverse grain sized sands. Due to the extremely low matrix permeability in active unconventional plays, the use of regional 40/70 and 100 mesh sands (50/140, 70/140, etc.) has become commonplace with adequate results. What remains is the need for enhanced conductivity near the wellbore to handle the radial flow convergence loss when the well is brought on-line. Research is being conducted to better understand how to efficiently increase near-wellbore conductivity using lead and tail-in stages with higher permeability (ceramic) proppant when frac sand is the majority of the material pumped into the well. A 10’x20’ Large Slot Flow (LSF) apparatus, equipped with multiple injection points, side-panel ports for leak-off and/or post-test injection, with the ability to be disassembled for sample analysis after testing, was utilized for this project. For this data, the inlet was moved to the centerline of the wall to allow for proppant and fluid to transport into an environment similar to a horizontal wellbore connecting with a transverse fracture. Various tests were conducted to study the depositional characteristics of lead and tail-in stages with ceramic proppant (15% BW-Lead, 5% BW-Tail) and a main stage of 100 mesh sand (80%). Three inlet positions were established in the lower, middle, and upper portion of the apparatus. Tests were recorded to visually capture the efficiency of placing the premium proppants near the wellbore for increased conductivity. A key addition to the study was the innovative, post-production analysis through the side-panel ports. Fluid was injected into the proppant pack to observe the effect of increased near-wellbore conductivity. To improve visibility, the fluid was colored with a fluorescent dye and observed under black lights. The injection front geometry was radial initially, but typically elongated toward the exit point after contacting the ceramic proppant. The amount of time and distance for the fluid to travel through the sand pack, as well as that for the fluid to reach the offtake point once the ceramic bed was reached, were monitored and recorded. The ratio of the velocities should represent a valid qualitative indication of the conductivity contrast of the two proppants.\u0000 This paper will describe the unique experimental configuration, outline the testing program for both deposition and post-production assessments performed on the deposits, along with results that could provide better design practices leading to improved transverse fracture performance.","PeriodicalId":10965,"journal":{"name":"Day 3 Thu, September 23, 2021","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76433515","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}
In gas wells, decreased/unstable production can occur due to difficult-to-predict dynamic effects resulted from late-life phenomena, such as liquid loading and flooding. To minimize the negative impact of these effects, maximize production and extend the wells’ lifetime, wells are often operated in an intermittent production regime. The goal of this work is to find the optimum production and shut-in cycles to maximize intermittent gas production as a decision support to operators. A framework suitable for single and multiple wells was developed by coupling a Deep Learning forward model trained on historical data with a population-based global optimizer, Particle Swarm Optimization (PSO). The forward model predicts the production rates and wellhead pressure during production and shut-in conditions, respectively. The PSO algorithm optimizes the operational criteria given operational and environmental objectives, such as maximizing production, minimizing start-up/shut-in actions, penalizing emissions under several constraints such as planned maintenances and meeting a contract production value. The accuracy of the Deep Learning models was tested on synthetic and field data. On synthetic data, mature wells were tested under different reservoir conditions such as initial water saturation, permeability and flow regimes. The relative errors in the predicted total cumulative production ranged between 0.5 and 4.6% for synthetic data and 0.9% for field data. The mean errors for pressure prediction were of 2-3 bar. The optimization framework was benchmarked for production optimization and contract value matching for a single-well (on field data) and a cluster of wells (synthetic data). Single-well production optimization of a North Sea well achieved a 3% production increase, including planned maintenances. Production optimization for six wells resulted in a 21% production increase for a horizon of 30 days, while contract value matching yielded 29/30 values within 3% of the target. The most optimum, repeatable and computationally efficient results were obtained using critical pressure/gas flowrates as operational criteria. This could enable real-time gas production optimization and operational decision-making in a wide range of well conditions and operational requirements.
{"title":"Data-Driven Optimization of Intermittent Gas Production in Mature Fields Assisted by Deep Learning and a Population-Based Global Optimizer","authors":"J. F. Gómez, P. S. Omrani, S. Belfroid","doi":"10.2118/206195-ms","DOIUrl":"https://doi.org/10.2118/206195-ms","url":null,"abstract":"In gas wells, decreased/unstable production can occur due to difficult-to-predict dynamic effects resulted from late-life phenomena, such as liquid loading and flooding. To minimize the negative impact of these effects, maximize production and extend the wells’ lifetime, wells are often operated in an intermittent production regime. The goal of this work is to find the optimum production and shut-in cycles to maximize intermittent gas production as a decision support to operators. A framework suitable for single and multiple wells was developed by coupling a Deep Learning forward model trained on historical data with a population-based global optimizer, Particle Swarm Optimization (PSO). The forward model predicts the production rates and wellhead pressure during production and shut-in conditions, respectively. The PSO algorithm optimizes the operational criteria given operational and environmental objectives, such as maximizing production, minimizing start-up/shut-in actions, penalizing emissions under several constraints such as planned maintenances and meeting a contract production value. The accuracy of the Deep Learning models was tested on synthetic and field data. On synthetic data, mature wells were tested under different reservoir conditions such as initial water saturation, permeability and flow regimes. The relative errors in the predicted total cumulative production ranged between 0.5 and 4.6% for synthetic data and 0.9% for field data. The mean errors for pressure prediction were of 2-3 bar. The optimization framework was benchmarked for production optimization and contract value matching for a single-well (on field data) and a cluster of wells (synthetic data). Single-well production optimization of a North Sea well achieved a 3% production increase, including planned maintenances. Production optimization for six wells resulted in a 21% production increase for a horizon of 30 days, while contract value matching yielded 29/30 values within 3% of the target. The most optimum, repeatable and computationally efficient results were obtained using critical pressure/gas flowrates as operational criteria. This could enable real-time gas production optimization and operational decision-making in a wide range of well conditions and operational requirements.","PeriodicalId":10965,"journal":{"name":"Day 3 Thu, September 23, 2021","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75943066","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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