The paper aims to highlight the importance of using adequate dynamic data to ground-truth reservoir simulation models early in the production life of a field. This study also highlights the benefits of adequate instrumentation and data capture, as well as the need to review assumptions made for green fields in their first few production years. This study reviews two vintages of probabilistic assessment for an offshore gas condensate reservoir. An earlier probabilistic assessment for the case study reservoir was built based primarily on core data from two analogous reservoirs, one of which was from the same field, prior to the availability of bottom hole pressure and drawdown data. Initial history match and forecasts showed a significantly poor production performance with significant impact on the condensate reserves volumes from the single well in the reservoir. Following the acquisition of pressure data from the downhole gauges and pressure transient analyses results, the model recalibrated in line with estimated distance to boundaries, drawdown and productivity indices. Incorporating the additional data from the downhole instrumentation during the history match showed the earth model severely underestimated the permeability of the reservoir. Matching the drawdown and well test data required a significant permeability multiplier for the low and mid case models for the reservoir. A comparison of results from both model vintages showed significant differences in the expected production plateau for the reservoir and consequently reserves estimates. These finding demonstrates value of the acquisition of multiple downhole dynamic data and the pitfalls with reservoir performance forecasts and reserves assessments when simulation models are not adequately constrained with dynamic well data early in the production life of the reservoir.
{"title":"Demonstrating the Value of Early Incorporation of Dynamic Data during Probabilistic Assessment for a Niger Delta Gas Condensate Reservoir","authors":"F. Ogbuagu, Lynn Silpngarmlers","doi":"10.2118/198830-MS","DOIUrl":"https://doi.org/10.2118/198830-MS","url":null,"abstract":"\u0000 The paper aims to highlight the importance of using adequate dynamic data to ground-truth reservoir simulation models early in the production life of a field. This study also highlights the benefits of adequate instrumentation and data capture, as well as the need to review assumptions made for green fields in their first few production years.\u0000 This study reviews two vintages of probabilistic assessment for an offshore gas condensate reservoir. An earlier probabilistic assessment for the case study reservoir was built based primarily on core data from two analogous reservoirs, one of which was from the same field, prior to the availability of bottom hole pressure and drawdown data. Initial history match and forecasts showed a significantly poor production performance with significant impact on the condensate reserves volumes from the single well in the reservoir.\u0000 Following the acquisition of pressure data from the downhole gauges and pressure transient analyses results, the model recalibrated in line with estimated distance to boundaries, drawdown and productivity indices. Incorporating the additional data from the downhole instrumentation during the history match showed the earth model severely underestimated the permeability of the reservoir. Matching the drawdown and well test data required a significant permeability multiplier for the low and mid case models for the reservoir.\u0000 A comparison of results from both model vintages showed significant differences in the expected production plateau for the reservoir and consequently reserves estimates. These finding demonstrates value of the acquisition of multiple downhole dynamic data and the pitfalls with reservoir performance forecasts and reserves assessments when simulation models are not adequately constrained with dynamic well data early in the production life of the reservoir.","PeriodicalId":11250,"journal":{"name":"Day 3 Wed, August 07, 2019","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81615190","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}
C. N. Adewumi, O. Achugasim, R. Ogali, O. Akaranta
Starches serve as vital raw materials in many industrial applications especially in food, textile, pharmaceutical and petroleum industries. In petroleum industry, chemically modified starches are used in water based drilling mud to enhance fluid loss and viscosity in the formation during drilling. Most starches used for these applications are obtained from food sources such as corn, potato and cassava and this affects the overall production cost. Artocarpus heterophyllus Lam (AHL) is a tropical tree with large bulb (fruit) containing pulp and seed. In Nigeria, this tree grows in the wild or homes but its fruit is not seen as a food source and thus allowed to waste. Starch was extracted from the pulp of unripe but matured AHL using wet milling method, and the extracted starch was examined for its proximate composition and physicochemical properties. Starch extraction from the unripe pulp gave a starch yield of 44.12±1.13% and the physicochemical characterization shows that the starch has high amylose content (24.09±0.11%), water absorption capacity (116±0.18%), gelatinization temperature (71°C) and the swelling power increases with increase in temperature. The thermal behavior of the starch studied with differential scanning calorimeter (DSC) demonstrated a distinguished endothermic peak with distinct onset, peak and conclusion temperatures. The scanning electron microscope (SEM) result showed that the starch granules are small sized and aggregate together with high tendency of forming network of granules. The results obtained from the physicochemical characterization of unripe AHL pulp starch shows that it has high potential for oilfield applications.
{"title":"Physicochemical Characterization of Starch from Unripe Artocarpus heterophyllus Lam Pulp as a Low-Cost Starch Source for Oilfield Applications","authors":"C. N. Adewumi, O. Achugasim, R. Ogali, O. Akaranta","doi":"10.2118/198746-MS","DOIUrl":"https://doi.org/10.2118/198746-MS","url":null,"abstract":"\u0000 Starches serve as vital raw materials in many industrial applications especially in food, textile, pharmaceutical and petroleum industries. In petroleum industry, chemically modified starches are used in water based drilling mud to enhance fluid loss and viscosity in the formation during drilling. Most starches used for these applications are obtained from food sources such as corn, potato and cassava and this affects the overall production cost. Artocarpus heterophyllus Lam (AHL) is a tropical tree with large bulb (fruit) containing pulp and seed. In Nigeria, this tree grows in the wild or homes but its fruit is not seen as a food source and thus allowed to waste. Starch was extracted from the pulp of unripe but matured AHL using wet milling method, and the extracted starch was examined for its proximate composition and physicochemical properties. Starch extraction from the unripe pulp gave a starch yield of 44.12±1.13% and the physicochemical characterization shows that the starch has high amylose content (24.09±0.11%), water absorption capacity (116±0.18%), gelatinization temperature (71°C) and the swelling power increases with increase in temperature. The thermal behavior of the starch studied with differential scanning calorimeter (DSC) demonstrated a distinguished endothermic peak with distinct onset, peak and conclusion temperatures. The scanning electron microscope (SEM) result showed that the starch granules are small sized and aggregate together with high tendency of forming network of granules. The results obtained from the physicochemical characterization of unripe AHL pulp starch shows that it has high potential for oilfield applications.","PeriodicalId":11250,"journal":{"name":"Day 3 Wed, August 07, 2019","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89784787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper is intended to tackle and treat the subject of global warming which includes its components, current issues, trends and challenges to enable us to add our own mitigation measures to support the global efforts on its reduction. The caustic effects would be analyzed using environmental data gotten from Environmental Impact Assessment (EIA) studies and Environmental Evaluation Report (EER) from various field locations in the oil production fields in the Niger Delta region of Nigeria. Analysis of the various cleaner energy alternatives other than fossil fuels would be done, with individual challenges of these alternatives been highlighted, from which a projection for the zone under study would be done using graphs and data plotted in Excel. Mitigation strategies has been suggested and backed with adequate recommendations that are gotten from sample opinions from experts in environmental matters in the oil and gas industry.
{"title":"Global Warming Issues, Challenges & Vulnerable Africa – Cleaner Energy Possibilities, Emission Reduction Analysis and Mitigation Strategies","authors":"E. Umeh, Cyprian Onyekperem","doi":"10.2118/198778-MS","DOIUrl":"https://doi.org/10.2118/198778-MS","url":null,"abstract":"\u0000 This paper is intended to tackle and treat the subject of global warming which includes its components, current issues, trends and challenges to enable us to add our own mitigation measures to support the global efforts on its reduction. The caustic effects would be analyzed using environmental data gotten from Environmental Impact Assessment (EIA) studies and Environmental Evaluation Report (EER) from various field locations in the oil production fields in the Niger Delta region of Nigeria. Analysis of the various cleaner energy alternatives other than fossil fuels would be done, with individual challenges of these alternatives been highlighted, from which a projection for the zone under study would be done using graphs and data plotted in Excel. Mitigation strategies has been suggested and backed with adequate recommendations that are gotten from sample opinions from experts in environmental matters in the oil and gas industry.","PeriodicalId":11250,"journal":{"name":"Day 3 Wed, August 07, 2019","volume":"52 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83793519","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 this study, a 3-Dimensional non-linear partial differential equation (PDE) describing flow of non-Newtonian fluid in porous media was developed for a no-flow boundary reservoir. Non-Newtonian fluid flow in porous media has direct applications in polymer flooding for secondary oil recovery operations and flow of heavy crude in the reservoir. This novel work presents the pressure behavior of horizontal wells with non-Newtonian fluid flow in porous media as well as the methodology for analyzing pressure transient data from non-Newtonian reservoirs. The main assumptions in the mathematical modeling of the differential equation are; permeability anisotropy with directional permeabilities kx, ky and kz horizontal well is in the y-direction perpendicular to direction of maximum permeability kx effects of gravity, skin and wellbore storage were neglected and the reservoir fluid was considered to be a non-Newtonian pseudo plastic fluid that obeys power law model in an isothermal condition. The derived equation was discretized using finite difference approach; A 3D numerical simulator was developed with the aid of MATLAB to solve the system of linear equations obtained from the discretization of a 15 X15 × 15 grid system to obtain pressure transient data. Type curves in terms of PwD and tD were generated for different power law flow index n ranging from 0.1 to 1 for horizontal well length of 600ft, 1000ft and 1200ft. The developed type curves in this study were validated with a Newtonian case using Tiab Direct synthesis (TDS) technique to analyze the radial flow regime for the determination of average permeability as well as the early linear flow for determining kx The results obtained from the Newtonian fluid case were very close to the actual property been determined.
{"title":"3D Numerical Modeling of Linear Flow of Non-Newtonian Fluid in Porous Media: Application to Non-Newtonian Draw-Down Pressure Transient Analysis","authors":"K. Adenuga, G. Achumba, Ebuka Ezenworo","doi":"10.2118/198848-MS","DOIUrl":"https://doi.org/10.2118/198848-MS","url":null,"abstract":"\u0000 In this study, a 3-Dimensional non-linear partial differential equation (PDE) describing flow of non-Newtonian fluid in porous media was developed for a no-flow boundary reservoir. Non-Newtonian fluid flow in porous media has direct applications in polymer flooding for secondary oil recovery operations and flow of heavy crude in the reservoir. This novel work presents the pressure behavior of horizontal wells with non-Newtonian fluid flow in porous media as well as the methodology for analyzing pressure transient data from non-Newtonian reservoirs.\u0000 The main assumptions in the mathematical modeling of the differential equation are; permeability anisotropy with directional permeabilities kx, ky and kz horizontal well is in the y-direction perpendicular to direction of maximum permeability kx effects of gravity, skin and wellbore storage were neglected and the reservoir fluid was considered to be a non-Newtonian pseudo plastic fluid that obeys power law model in an isothermal condition.\u0000 The derived equation was discretized using finite difference approach; A 3D numerical simulator was developed with the aid of MATLAB to solve the system of linear equations obtained from the discretization of a 15 X15 × 15 grid system to obtain pressure transient data. Type curves in terms of PwD and tD were generated for different power law flow index n ranging from 0.1 to 1 for horizontal well length of 600ft, 1000ft and 1200ft.\u0000 The developed type curves in this study were validated with a Newtonian case using Tiab Direct synthesis (TDS) technique to analyze the radial flow regime for the determination of average permeability as well as the early linear flow for determining kx The results obtained from the Newtonian fluid case were very close to the actual property been determined.","PeriodicalId":11250,"journal":{"name":"Day 3 Wed, August 07, 2019","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88462844","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}
Wale Ajao, Ezinwanneakolam Isiba, Eddy Okoh, Immaculate Okoruwa, Stanley Omenai, Nicholas Abu, O. Babalola, Oluwatobi Oke
Oil Mining Lease 26 (OML 26) is held by NNPC and First Hydrocarbon Nigeria Limited (FHN) in a Joint Venture relationship and operated by an Asset Management Team (AMT). The license consists of several oil and gas discoveries including the Ogini, Isoko, and Ozoro fields on the western part, Ovo in the central area and Aboh to the east. Oil Production is mainly from the Ogini and Isoko fields with the Ogini field contributing the largest volume. The Ogini oil is relatively heavy, with in-situ oil viscosity ranging from 3 to 59cp, and an oil gravity ranging from 15°API to 19°API. Field development and production from the Ogini field has been very challenging with the characteristic low GOR, low rate and high watercut. Oil production peaked at 8,900 stb/d shortly after field start-up in the 80s and has been declining since then. In 2018 however, the field witnessed breakthrough performance stemming from production optimization initiatives and strategies which unlocked resource potential of the field. A peak production of ca 17,000 bopd was recorded during Q4 of 2018 without drilling new wells. A number of production enhancement activities carefully designed, planned, and executed coupled with change in operations philosophy released more volumes transforming the production levels and production profile of the field from a mere 3,000bopd to ca 17,000 bopd peak production. This paper highlights the strategies, optimization techniques and the paradigm shift in operational culture that resulted in the significant change and ramp up of production in the field.
{"title":"Production Optimization Strategies for Unlocking Resource Potential in A Heavy-Oil Brown Field - The OML26 Success Story","authors":"Wale Ajao, Ezinwanneakolam Isiba, Eddy Okoh, Immaculate Okoruwa, Stanley Omenai, Nicholas Abu, O. Babalola, Oluwatobi Oke","doi":"10.2118/198800-MS","DOIUrl":"https://doi.org/10.2118/198800-MS","url":null,"abstract":"\u0000 Oil Mining Lease 26 (OML 26) is held by NNPC and First Hydrocarbon Nigeria Limited (FHN) in a Joint Venture relationship and operated by an Asset Management Team (AMT). The license consists of several oil and gas discoveries including the Ogini, Isoko, and Ozoro fields on the western part, Ovo in the central area and Aboh to the east.\u0000 Oil Production is mainly from the Ogini and Isoko fields with the Ogini field contributing the largest volume. The Ogini oil is relatively heavy, with in-situ oil viscosity ranging from 3 to 59cp, and an oil gravity ranging from 15°API to 19°API. Field development and production from the Ogini field has been very challenging with the characteristic low GOR, low rate and high watercut. Oil production peaked at 8,900 stb/d shortly after field start-up in the 80s and has been declining since then.\u0000 In 2018 however, the field witnessed breakthrough performance stemming from production optimization initiatives and strategies which unlocked resource potential of the field. A peak production of ca 17,000 bopd was recorded during Q4 of 2018 without drilling new wells. A number of production enhancement activities carefully designed, planned, and executed coupled with change in operations philosophy released more volumes transforming the production levels and production profile of the field from a mere 3,000bopd to ca 17,000 bopd peak production. This paper highlights the strategies, optimization techniques and the paradigm shift in operational culture that resulted in the significant change and ramp up of production in the field.","PeriodicalId":11250,"journal":{"name":"Day 3 Wed, August 07, 2019","volume":"147 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76089828","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}
Ogochukwu Benyeogor, D. Jambol, O. Amah, D. Obiga, S. Awe, A. Erinle
Managed pressure drilling (MPD) is an adaptive drilling technique used to improve the economics and to mitigate risks associated with drilling high pressure and high temperature (HPHT) exploration wells where the drilling window is often narrow. The technique involves the combination of surface back pressure and fluid hydrostatic column to provide the required bottom hole pressure for safe drilling. Typical MPD equipment spread includes rotating control device (RCD), chokes, high pressure lines and gate valves with Pressure relief valves (PRVs) incorporated. The primary purpose of the PRV is to protect the MPD surface equipment and the formation from being overpressured. The relief valve achieves this by bypassing the normal fluid flow path for MPD operations and relieving the system pressure to the rig Mud gas separator (MGS) through a dedicated line. Each time a PRV is activated the resulting loss of surface back pressure increases the risk of taking a kick. On the other hand, when a PRV is not activated, an excessive increase in surface pressure raises the risk of formation fracture leading to losses. Therefore, the performance of the PRV has an immense impact on assessing the risk of a well control situation, which may be caused by either loses due to formation breakdown and consequently a kick from loss of the hydrostatic pressure component of the equivalent surface density (ESD) or an influx as a result of loss of surface back pressure component of the ESD due to loss of integrity of surface equipment). Pressure Relief Management philosophy generally covers decisions such as which parts of the well system (surface and subsurface) are to be preferentially protected by the PRVs, selection of activation pressure for high level alarms, types, number and setpoints of PRVs in the MPD system during different phases of the drilling operations - drilling, connections and tripping, and MPD choke full-opening pressure. These values are dependent on formation integrity test (FIT), mud weight, drilling window, annular friction pressure and operating envelope of RCD. The set points require adjustment depending on the hole size and flow rate and may be different during completion and well control operations. This paper describes the Pressure Relief Management philosophy for a HPHT well drilled in the Niger delta. It looks at factors that drive the high-pressure alarm setting values, choice of PRV types, placement and the part of the well system being protected, PRV tripping and reset values, and MPD choke full opening pressures. It also describes the challenges and risk assessment that influenced the selection of set points (single or dual setpoints) for different phases of the drilling operations.
{"title":"Pressure Relief Management Philosophy for MPD Operations on Surface Stack HPHT Exploration Wells","authors":"Ogochukwu Benyeogor, D. Jambol, O. Amah, D. Obiga, S. Awe, A. Erinle","doi":"10.2118/198812-MS","DOIUrl":"https://doi.org/10.2118/198812-MS","url":null,"abstract":"\u0000 Managed pressure drilling (MPD) is an adaptive drilling technique used to improve the economics and to mitigate risks associated with drilling high pressure and high temperature (HPHT) exploration wells where the drilling window is often narrow. The technique involves the combination of surface back pressure and fluid hydrostatic column to provide the required bottom hole pressure for safe drilling. Typical MPD equipment spread includes rotating control device (RCD), chokes, high pressure lines and gate valves with Pressure relief valves (PRVs) incorporated. The primary purpose of the PRV is to protect the MPD surface equipment and the formation from being overpressured. The relief valve achieves this by bypassing the normal fluid flow path for MPD operations and relieving the system pressure to the rig Mud gas separator (MGS) through a dedicated line. Each time a PRV is activated the resulting loss of surface back pressure increases the risk of taking a kick. On the other hand, when a PRV is not activated, an excessive increase in surface pressure raises the risk of formation fracture leading to losses. Therefore, the performance of the PRV has an immense impact on assessing the risk of a well control situation, which may be caused by either loses due to formation breakdown and consequently a kick from loss of the hydrostatic pressure component of the equivalent surface density (ESD) or an influx as a result of loss of surface back pressure component of the ESD due to loss of integrity of surface equipment).\u0000 Pressure Relief Management philosophy generally covers decisions such as which parts of the well system (surface and subsurface) are to be preferentially protected by the PRVs, selection of activation pressure for high level alarms, types, number and setpoints of PRVs in the MPD system during different phases of the drilling operations - drilling, connections and tripping, and MPD choke full-opening pressure. These values are dependent on formation integrity test (FIT), mud weight, drilling window, annular friction pressure and operating envelope of RCD. The set points require adjustment depending on the hole size and flow rate and may be different during completion and well control operations.\u0000 This paper describes the Pressure Relief Management philosophy for a HPHT well drilled in the Niger delta. It looks at factors that drive the high-pressure alarm setting values, choice of PRV types, placement and the part of the well system being protected, PRV tripping and reset values, and MPD choke full opening pressures. It also describes the challenges and risk assessment that influenced the selection of set points (single or dual setpoints) for different phases of the drilling operations.","PeriodicalId":11250,"journal":{"name":"Day 3 Wed, August 07, 2019","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91108428","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}
Osazua J. Itua, T. Jenakumo, Mohammed Hafiz Ringim, A. D. Kuijper
Assessing well integrity through cement bond analysis is recommended and sometimes legally required because the potential risk of a poorly executed cement job on people, assets and environment during- and post well construction can be catastrophic. Traditionally, cement bond logs were acquired with wireline tools. Following advances in tool response modelling and log data processing, Logging While Drilling (LWD) acoustic data for cement bond analysis - acquiring the data while tripping in or tripping out of hole - has become an attractive and viable option to consider over traditional wireline data acquisition. The LWD option comes with the added advantage of substantial savings in rig time while eliminating operational complexity and safety risks associated with additional wireline logging operation particularly in high angle- and extended reach wells. To assess the robustness of the LWD cased hole cement evaluation logs and to validate its application to Deep Water (DW) wells, LWD and wireline acoustic logs were acquired back-to-back in three wells in the DW Gulf of Guinea (GoG), and the bond index estimated from both acquisitions were compared. This paper presents the outcome of the work and provides support to the opportunity to consider LWD acoustic data acquisition for quantitative cement bond evaluation.
{"title":"Logging While Drilling Cement Evaluation: Case Study in Deep Water Gulf of Guinea","authors":"Osazua J. Itua, T. Jenakumo, Mohammed Hafiz Ringim, A. D. Kuijper","doi":"10.2118/198755-MS","DOIUrl":"https://doi.org/10.2118/198755-MS","url":null,"abstract":"\u0000 Assessing well integrity through cement bond analysis is recommended and sometimes legally required because the potential risk of a poorly executed cement job on people, assets and environment during- and post well construction can be catastrophic. Traditionally, cement bond logs were acquired with wireline tools. Following advances in tool response modelling and log data processing, Logging While Drilling (LWD) acoustic data for cement bond analysis - acquiring the data while tripping in or tripping out of hole - has become an attractive and viable option to consider over traditional wireline data acquisition. The LWD option comes with the added advantage of substantial savings in rig time while eliminating operational complexity and safety risks associated with additional wireline logging operation particularly in high angle- and extended reach wells.\u0000 To assess the robustness of the LWD cased hole cement evaluation logs and to validate its application to Deep Water (DW) wells, LWD and wireline acoustic logs were acquired back-to-back in three wells in the DW Gulf of Guinea (GoG), and the bond index estimated from both acquisitions were compared. This paper presents the outcome of the work and provides support to the opportunity to consider LWD acoustic data acquisition for quantitative cement bond evaluation.","PeriodicalId":11250,"journal":{"name":"Day 3 Wed, August 07, 2019","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84916388","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}
O. Kuku, A. Ekeigwe, G. Ajakaiye, Tammy Olushina, C. Harper, Y. Zheng, S. A. Green
The X field has been in production since 2011 and some of the reservoirs are on a water flooding-scheme for pressure support. The water flood commenced solely with the injection of seawater and more recently commingled produced water and seawater. A few years into the production, it was observed that production from at least one of the reservoirs has become sour. Thus, a reservoir souring study of the X field was conducted to ascertain the immediate cause of souring, determine future sulphide production trend and provide recommendations on sulphide concentration and integrity monitoring, bacteria monitoring practices and mitigation against the current souring events on the X field. The study was conducted by a joint team from Oriental Energy Resources Limited (OERL) - operator, Baker Hughes, a GE company (BHGE) in collaboration with the regulatory agency, the Department of Petroleum Resources (DPR). The study utilized BHGE proprietary workflows, including those previously documented in SPE-179921-MS, and drew on significant routine operational data, and specialized data such as sulphide and sulphate isotopes, detailed water compositions (including Volatile Fatty Acids -VFA), serial dilution and molecular microbiological enumeration techniques and microbiological sequencing techniques. The study concluded that the primary source of souring was microbiological and that this souring event was not limited to the focus, high H2S reservoir (XY) but was observed to be present on all water injected reservoirs in the X field. It was felt, though not proven, that the Sulphate Reducing Bacteria (SRB) may have been derived from the seawater. The microbiological Deoxyribonucleic Acid (DNA) analyses indicated that the primary carbon source, once VFA had been sufficiently depleted, was likely to be the biodegradation products of hydrocarbon degrading bacteria within the reservoir. The study also concluded that, due to the lack of carbon source constraint for the bacteria, the required inhibitory nitrate dose rates would be uneconomically high and would yield no benefit over the effects of replacing Sea Water Injection (SWI) with Produced Water Re-Injection (PWRI). However, it has been observed that sulphate concentration in production had declined since the cessation of seawater injection. The reservoir souring study has resulted in a heightened level of surveillance, thereby leading to a safer operating environment on the X asset. The field operating strategy and chemical application has been modified to allow the overall magnitude of sulphide related hazards and cost of operating the field to be reduced. This project is a first in the Nigerian oil production operations, involving an open collaboration between an operator, a government body and a service vendor on reservoir souring.
{"title":"The Application of Holistic Workflows for Sour Reservoir Management on the X Field","authors":"O. Kuku, A. Ekeigwe, G. Ajakaiye, Tammy Olushina, C. Harper, Y. Zheng, S. A. Green","doi":"10.2118/198849-MS","DOIUrl":"https://doi.org/10.2118/198849-MS","url":null,"abstract":"\u0000 The X field has been in production since 2011 and some of the reservoirs are on a water flooding-scheme for pressure support. The water flood commenced solely with the injection of seawater and more recently commingled produced water and seawater. A few years into the production, it was observed that production from at least one of the reservoirs has become sour.\u0000 Thus, a reservoir souring study of the X field was conducted to ascertain the immediate cause of souring, determine future sulphide production trend and provide recommendations on sulphide concentration and integrity monitoring, bacteria monitoring practices and mitigation against the current souring events on the X field.\u0000 The study was conducted by a joint team from Oriental Energy Resources Limited (OERL) - operator, Baker Hughes, a GE company (BHGE) in collaboration with the regulatory agency, the Department of Petroleum Resources (DPR).\u0000 The study utilized BHGE proprietary workflows, including those previously documented in SPE-179921-MS, and drew on significant routine operational data, and specialized data such as sulphide and sulphate isotopes, detailed water compositions (including Volatile Fatty Acids -VFA), serial dilution and molecular microbiological enumeration techniques and microbiological sequencing techniques.\u0000 The study concluded that the primary source of souring was microbiological and that this souring event was not limited to the focus, high H2S reservoir (XY) but was observed to be present on all water injected reservoirs in the X field. It was felt, though not proven, that the Sulphate Reducing Bacteria (SRB) may have been derived from the seawater. The microbiological Deoxyribonucleic Acid (DNA) analyses indicated that the primary carbon source, once VFA had been sufficiently depleted, was likely to be the biodegradation products of hydrocarbon degrading bacteria within the reservoir.\u0000 The study also concluded that, due to the lack of carbon source constraint for the bacteria, the required inhibitory nitrate dose rates would be uneconomically high and would yield no benefit over the effects of replacing Sea Water Injection (SWI) with Produced Water Re-Injection (PWRI). However, it has been observed that sulphate concentration in production had declined since the cessation of seawater injection.\u0000 The reservoir souring study has resulted in a heightened level of surveillance, thereby leading to a safer operating environment on the X asset. The field operating strategy and chemical application has been modified to allow the overall magnitude of sulphide related hazards and cost of operating the field to be reduced.\u0000 This project is a first in the Nigerian oil production operations, involving an open collaboration between an operator, a government body and a service vendor on reservoir souring.","PeriodicalId":11250,"journal":{"name":"Day 3 Wed, August 07, 2019","volume":"61 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84669337","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 efficiency of cuttings transport is very important factor for a good drilling operation program. The transportation of these cuttings through the annulus is a complex problem that is affected by many parameters. For effective cuttings transport prediction, it will require that all these parameters be considered simultaneously. Predictions of pressure losses and cuttings transportation through the annulus are very complex during drilling operation due to the combination of interacting drilling parameters. Success during drilling program is due to efficiently cleaned hole. For better understanding of the effects of some of these parameters that affect cutting transportation, the power law of non-Newtonian viscosity model was adopted to establish the mathematical model of the cutting transport process in the well annulus. Some of the hole-cleaning challenges focused are: the absence of the basic data needed to fully evaluate present field practices and current concepts on drill cutting transport, the combined effect of operational parameters and drilling fluid properties, the effect of operational parameters and cutting properties and what is the effect of rheology model on cutting transport simulation. Poor hole-cleaning during drilling can lead to a lot of bore hole issues which has a negative effects. The overall effect is increase in drilling time and drilling cost. The proposed tool allows more precise prediction of cuttings transport property in the whole range of the well. In this paper, the effects of annular fluid velocity, transport ratio, size and density of cuttings are investigated. The results obtained showed that the most important factors controlling cutting transport are annular velocity and the fluid rheological properties. From the simulation result, it can be observed that an optimum transport ratio was obtained at 1.42m/s. The transport ratio increases rapidly with velocity but then begins to level out or increase more slowly in the velocity range of 1.42 to 1.62 m/s. We can also deduce from the result that cuttings velocity increases with the flow rate; but this increment does not follow a linear behaviour.
{"title":"Evaluation of Cuttings Transport in Well Annulus Using Power Law Model","authors":"Edward K. Menegbo, Eme Charles, A. Dosunmu","doi":"10.2118/198825-MS","DOIUrl":"https://doi.org/10.2118/198825-MS","url":null,"abstract":"\u0000 The efficiency of cuttings transport is very important factor for a good drilling operation program. The transportation of these cuttings through the annulus is a complex problem that is affected by many parameters. For effective cuttings transport prediction, it will require that all these parameters be considered simultaneously. Predictions of pressure losses and cuttings transportation through the annulus are very complex during drilling operation due to the combination of interacting drilling parameters. Success during drilling program is due to efficiently cleaned hole. For better understanding of the effects of some of these parameters that affect cutting transportation, the power law of non-Newtonian viscosity model was adopted to establish the mathematical model of the cutting transport process in the well annulus. Some of the hole-cleaning challenges focused are: the absence of the basic data needed to fully evaluate present field practices and current concepts on drill cutting transport, the combined effect of operational parameters and drilling fluid properties, the effect of operational parameters and cutting properties and what is the effect of rheology model on cutting transport simulation. Poor hole-cleaning during drilling can lead to a lot of bore hole issues which has a negative effects. The overall effect is increase in drilling time and drilling cost. The proposed tool allows more precise prediction of cuttings transport property in the whole range of the well. In this paper, the effects of annular fluid velocity, transport ratio, size and density of cuttings are investigated. The results obtained showed that the most important factors controlling cutting transport are annular velocity and the fluid rheological properties. From the simulation result, it can be observed that an optimum transport ratio was obtained at 1.42m/s. The transport ratio increases rapidly with velocity but then begins to level out or increase more slowly in the velocity range of 1.42 to 1.62 m/s. We can also deduce from the result that cuttings velocity increases with the flow rate; but this increment does not follow a linear behaviour.","PeriodicalId":11250,"journal":{"name":"Day 3 Wed, August 07, 2019","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85602997","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}
Transparency in information is one of the most important undertaking that the government in collaboration with oil and gas stakeholders can offer to the public. Open, and therefore, accessible, nonproprietary data in the current information age is a tool for improved governance, transparency and innovation. The oil and gas industry is a huge data generator through its daily operations, it is a leader and in fact, a home to big data. From existing development assets, to supply chains, customer relations etc, data provides a competitive advantage for organizational growth and management. Beyond the strategic opportunities that big data provides within the industry, is the enormous capabilities that big data through open data initiatives can have on company-community relations. In this paper, we examine the various acts and legislations governing oil and gas industry operations and their position on data transparency. Our examination sheds light on current positions of the tripartite of law, policy and practice and the demonstrated gaps between this tripartite. In addition to the legal analysis, we also examine the issue of open data through the petroleum engineering prism. The benefits and significant impact a movement in open data will deliver to the industry are also examined which include but are not limited to: addressing public concerns and increasing community workforce participation and protection of oil and non-oil natural resources. Finally, because discussion on open data is incomplete without the necessary data literacy skills needed to utilize, analyze and draw meaningful conclusions from data, we examine how best we can increase these skills within the community to bridge the information divide. As we enter 20 years of steady democracy and political process in Nigeria, open data will certainly disband doubts and fake news in our energy conversations as it will provide a level playing field for all parties. Public discourse will be more focused on facts and lead to improved and sound decision making.
{"title":"Towards Information Transparency: Current Posture and Advocacy for Open Data Systems for Efficiency, Equity and Justice – The Nigerian Oil and Gas Experience","authors":"M. A. Ante, A. Ante","doi":"10.2118/198795-MS","DOIUrl":"https://doi.org/10.2118/198795-MS","url":null,"abstract":"\u0000 Transparency in information is one of the most important undertaking that the government in collaboration with oil and gas stakeholders can offer to the public. Open, and therefore, accessible, nonproprietary data in the current information age is a tool for improved governance, transparency and innovation.\u0000 The oil and gas industry is a huge data generator through its daily operations, it is a leader and in fact, a home to big data. From existing development assets, to supply chains, customer relations etc, data provides a competitive advantage for organizational growth and management. Beyond the strategic opportunities that big data provides within the industry, is the enormous capabilities that big data through open data initiatives can have on company-community relations.\u0000 In this paper, we examine the various acts and legislations governing oil and gas industry operations and their position on data transparency. Our examination sheds light on current positions of the tripartite of law, policy and practice and the demonstrated gaps between this tripartite. In addition to the legal analysis, we also examine the issue of open data through the petroleum engineering prism. The benefits and significant impact a movement in open data will deliver to the industry are also examined which include but are not limited to: addressing public concerns and increasing community workforce participation and protection of oil and non-oil natural resources.\u0000 Finally, because discussion on open data is incomplete without the necessary data literacy skills needed to utilize, analyze and draw meaningful conclusions from data, we examine how best we can increase these skills within the community to bridge the information divide.\u0000 As we enter 20 years of steady democracy and political process in Nigeria, open data will certainly disband doubts and fake news in our energy conversations as it will provide a level playing field for all parties. Public discourse will be more focused on facts and lead to improved and sound decision making.","PeriodicalId":11250,"journal":{"name":"Day 3 Wed, August 07, 2019","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80684000","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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